/* =========================================================================
   MATHY SAT - UI COMPONENTS AND RESPONSIVE STYLES
   ========================================================================= */
    .brand {
      display: flex;
      align-items: center;
      gap: 12px;
      background: none;
      border: none;
      color: var(--fg);
      text-align: left;
      cursor: pointer;
      margin-bottom: 20px;
      padding: 6px 8px;
      border-radius: 10px;
    }

    .brand-lamp-icon {
      width: 40px;
      height: 40px;
      flex-shrink: 0;
      display: flex;
    }
    .brand-lamp-icon .ace-logo { width: 100%; height: 100%; display: block; }

    .brand-title {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--fg);
      line-height: 1.1;
    }

    .brand-tag {
      font-size: 0.68rem;
      color: var(--accent);
      letter-spacing: 0.12em;
      font-family:var(--font-ui);
    }

    .streak-badge {
      margin-bottom: 18px;
      background: linear-gradient(135deg, rgba(245, 158, 11, 0.12), rgba(56, 189, 248, 0.08));
      border: 1px solid var(--border-glow);
      border-radius: 12px;
      padding: 10px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    nav {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .nav-btn {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 10px 14px;
      border-radius: 9px;
      border: 1px solid transparent;
      background: transparent;
      color: var(--muted-fg);
      font-size: 0.92rem;
      font-family:var(--font-ui);
      font-weight: 600;
      cursor: pointer;
      text-align: left;
      transition: all 0.2s;
    }

    .nav-btn:hover {
      background: var(--surface-raised);
      color: var(--fg);
      border-color: var(--border);
    }

    .nav-btn.active {
      background: var(--surface-raised);
      color: var(--primary);
      border-color: var(--border-glow);
      box-shadow: 0 4px 16px rgba(245, 158, 11, 0.12);
    }

    .theme-toggle-btn {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 9px;
      margin-top: 10px;
      border-radius: 9px;
      border: 1px solid var(--border);
      background: var(--surface-raised);
      color: var(--fg);
      font-size: 0.85rem;
      cursor: pointer;
      font-family:var(--font-ui);
    }

    .theme-toggle-btn:hover {
      border-color: var(--primary);
      color: var(--primary);
    }

    .sidebar-footer {
      margin-top: auto;
      background: var(--surface-card);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 12px;
    }

    .sidebar-footer h4 {
      font-size: 0.82rem;
      font-weight: 700;
      color: var(--primary);
    }

    .sidebar-footer p {
      font-size: 0.74rem;
      color: var(--muted-fg);
      margin-top: 4px;
      line-height: 1.4;
    }

    main {
      flex: 1;
      min-width: 0;
      display: flex;
      flex-direction: column;
    }

    .mobile-header {
      display: none;
      align-items: center;
      justify-content: space-between;
      padding: 12px 16px;
      background: var(--surface);
      border-bottom: 1px solid var(--border);
      position: sticky;
      top: 0;
      z-index: 50;
    }

    @media (max-width: 900px) {
      aside {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
    }

    /* Phones: the logo, streak, theme and 6 nav icons must fit in ~360px without widening the page. */
    @media (max-width: 520px) {
      .mobile-header { padding: 10px 8px; gap: 6px; }
      .mobile-header .brand-title { display: none; }
      .mobile-header > div { gap: 2px !important; min-width: 0; overflow-x: auto; scrollbar-width: none; }
      .mobile-header .nav-btn { width: 38px; height: 38px; min-width: 0; padding: 0; gap: 0; justify-content: center; flex-shrink: 0; }
      .mobile-header .filter-pill { padding: 4px 8px; }
      .mobile-header .nav-btn svg { width: 20px; height: 20px; }
    }

    .page-content {
      padding: 32px 24px 64px;
      max-width: 1180px;
      margin: 0 auto;
      width: 100%;
    }

    .panel {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 14px;
      padding: 24px;
      box-shadow: var(--shadow-panel);
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 10px 20px;
      border-radius: 9px;
      font-size: 0.9rem;
      font-family:var(--font-ui);
      font-weight: 700;
      cursor: pointer;
      border: none;
      transition: all 0.2s;
    }

    .btn:hover {
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    }

    .btn:active {
      transform: translateY(1px);
    }

    .btn-primary {
      background: var(--gold-gradient);
      color: var(--primary-fg);
      box-shadow: 0 4px 16px var(--primary-glow);
    }

    .btn-secondary {
      background: var(--secondary);
      color: var(--secondary-fg);
      border: 1px solid var(--border);
    }

    .btn-secondary:hover {
      background: var(--surface-raised);
      border-color: var(--primary);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--border);
      color: var(--fg);
    }

    .btn-outline:hover {
      border-color: var(--accent);
      color: var(--accent);
    }

    .badge {
      display: inline-flex;
      align-items: center;
      padding: 4px 10px;
      border-radius: 9999px;
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.08em;
      font-family:var(--font-ui);
    }

    .badge-primary {
      background: rgba(245, 158, 11, 0.15);
      border: 1px solid rgba(245, 158, 11, 0.4);
      color: var(--primary);
    }

    .badge-cyan {
      background: rgba(56, 189, 248, 0.15);
      border: 1px solid rgba(56, 189, 248, 0.35);
      color: var(--accent);
    }

    .badge-muted {
      background: var(--muted);
      color: var(--muted-fg);
      border: 1px solid var(--border);
    }

    .badge-success {
      background: var(--success-bg);
      color: var(--success);
      border: 1px solid var(--success);
    }

    .badge-destructive {
      background: var(--destructive-bg);
      color: var(--destructive);
      border: 1px solid var(--destructive);
    }

    .grid-paper {
      background-image:
        linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
        linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
      background-size: 26px 26px;
    }

    .text-gold {
      color: inherit;
    }

    .choice-btn {
      display: flex;
      align-items: center;
      gap: 14px;
      width: 100%;
      padding: 14px 18px;
      background: var(--surface-card);
      border: 1px solid var(--border);
      border-radius: 10px;
      color: var(--fg);
      font-size: 1.05rem;
      font-family: 'STIX Two Text', serif;
      cursor: pointer;
      text-align: left;
      transition: background 0.2s, border-color 0.2s;
    }

    .choice-btn:hover:not(.eliminated):not(.right):not(.wrong) {
      background: var(--surface-raised);
      border-color: var(--accent);
    }

    .choice-btn.right {
      border-color: var(--success) !important;
      background: var(--success-bg) !important;
      color: var(--success) !important;
      font-weight: 700;
    }

    .choice-btn.wrong {
      border-color: var(--destructive) !important;
      background: var(--destructive-bg) !important;
      color: var(--destructive) !important;
      font-weight: 700;
    }

    .choice-btn.selected {
      border-color: var(--accent) !important;
      background: rgba(56, 189, 248, 0.12) !important;
      box-shadow: 0 0 10px rgba(56, 189, 248, 0.25);
    }

    /* Bluebook Answer Choice Eliminator */
    .choice-btn.eliminated {
      opacity: 0.52;
      background: rgba(244, 63, 94, 0.05);
      border-color: rgba(244, 63, 94, 0.28);
    }

    .choice-btn.eliminated:hover {
      opacity: 0.72;
      border-color: rgba(244, 63, 94, 0.48);
    }

    .choice-btn.eliminated .choice-letter {
      opacity: 0.5;
      text-decoration: line-through;
      background: rgba(244, 63, 94, 0.1);
      color: var(--destructive);
      border: 1px dashed var(--destructive);
    }

    .choice-content {
      position: relative;
      display: inline-block;
      line-height: 1.5;
    }

    .choice-btn.eliminated .choice-content {
      text-decoration: line-through;
      text-decoration-color: var(--destructive);
      text-decoration-thickness: 2px;
      color: var(--muted-fg);
    }

    /* Solid horizontal strike across formulas & KaTeX */
    .choice-btn.eliminated .choice-content::after {
      content: '';
      position: absolute;
      left: -4px;
      right: -4px;
      top: 50%;
      height: 2px;
      background: var(--destructive, #f43f5e);
      transform: translateY(-50%);
      pointer-events: none;
      border-radius: 2px;
      box-shadow: 0 0 6px rgba(244, 63, 94, 0.35);
    }

    .choice-btn.eliminated .katex {
      opacity: 0.65;
    }

    /* Bluebook Eliminator Active Mode Visual Cue */
    .choice-btn.eliminator-mode-active {
      border-style: dashed;
      border-color: rgba(244, 63, 94, 0.45);
      cursor: pointer;
    }

    .choice-btn.eliminator-mode-active:hover {
      border-color: var(--destructive);
      background: rgba(244, 63, 94, 0.08);
    }

    .choice-eliminate-btn {
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 6px;
      padding: 5px 10px;
      color: var(--muted-fg);
      font-family:var(--font-ui);
      font-size: 0.82rem;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 4px;
      transition: all 0.15s ease;
      margin-left: auto;
      flex-shrink: 0;
      z-index: 2;
      user-select: none;
      min-height: 32px;
    }

    .choice-eliminate-btn:hover {
      background: rgba(244, 63, 94, 0.15);
      border-color: var(--destructive);
      color: #fb7185;
      transform: scale(1.06);
    }

    .choice-eliminate-btn:focus-visible {
      outline: 2px solid var(--primary);
      outline-offset: 2px;
    }

    .choice-eliminate-btn.eliminated {
      background: rgba(244, 63, 94, 0.22);
      border-color: var(--destructive);
      color: var(--destructive);
      font-weight: 800;
      box-shadow: 0 0 8px rgba(244, 63, 94, 0.3);
    }

    .choice-eliminate-badge {
      font-family:var(--font-ui);
      font-size: 0.78rem;
      padding: 3px 8px;
      border-radius: 6px;
      margin-left: auto;
      flex-shrink: 0;
    }

    .choice-eliminate-badge.eliminated {
      background: rgba(244, 63, 94, 0.14);
      color: var(--destructive);
      border: 1px solid rgba(244, 63, 94, 0.3);
    }

    /* Light Theme Bluebook Adaptations */
    :root[data-theme="light"] .choice-btn.eliminated {
      background: rgba(225, 29, 72, 0.05);
      border-color: rgba(225, 29, 72, 0.3);
    }

    :root[data-theme="light"] .choice-eliminate-btn {
      background: #f1f5f9;
      border-color: #cbd5e1;
      color: #64748b;
    }

    :root[data-theme="light"] .choice-eliminate-btn:hover {
      background: rgba(225, 29, 72, 0.12);
      border-color: var(--destructive);
      color: var(--destructive);
    }

    :root[data-theme="light"] .choice-eliminate-btn.eliminated {
      background: rgba(225, 29, 72, 0.18);
      border-color: var(--destructive);
      color: var(--destructive);
    }

    /* Question Bank Responsive Choice Grid */
    .bank-choices-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
      margin-bottom: 14px;
    }

    @media (max-width: 680px) {
      .bank-choices-grid {
        grid-template-columns: 1fr;
      }
    }


    .choice-letter {
      width: 28px;
      height: 28px;
      border-radius: 8px;
      background: var(--muted);
      color: var(--muted-fg);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.85rem;
      font-weight: bold;
      flex-shrink: 0;
      font-family:var(--font-ui);
    }

    .filter-pill {
      padding: 7px 16px;
      border-radius: 9999px;
      font-size: 0.78rem;
      font-weight: 700;
      font-family:var(--font-ui);
      border: 1px solid var(--border);
      background: var(--surface);
      color: var(--muted-fg);
      cursor: pointer;
      transition: all 0.2s;
    }

    .filter-pill:hover {
      color: var(--fg);
      background: var(--surface-raised);
      border-color: var(--accent);
    }

    .filter-pill.active {
      background: var(--gold-gradient);
      border-color: transparent;
      color: var(--primary-fg);
      box-shadow: 0 2px 10px var(--primary-glow);
    }

    .filter-pill.subtopic-pill {
      padding: 5px 12px;
      font-size: 0.74rem;
      font-family: 'Inter', system-ui, -apple-system, sans-serif;
      font-weight: 600;
      border-radius: 8px;
    }

    .filter-pill.subtopic-pill.active {
      background: var(--primary);
      color: #0b0f19;
      font-weight: 700;
      box-shadow: 0 2px 8px var(--primary-glow);
    }

    .subtopic-chips-tray {
      animation: fadeInSubtopics 0.2s ease-in-out;
    }

    @keyframes fadeInSubtopics {
      from { opacity: 0; transform: translateY(-4px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .sub-tabs-bar {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      padding: 6px;
      background: var(--surface-card);
      border: 1px solid var(--border);
      border-radius: 12px;
      margin-bottom: 24px;
    }

    .sub-tab-btn {
      padding: 9px 18px;
      border-radius: 8px;
      border: none;
      background: transparent;
      color: var(--muted-fg);
      font-family:var(--font-ui);
      font-size: 0.85rem;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.2s;
    }

    .sub-tab-btn:hover {
      color: var(--fg);
      background: var(--surface-raised);
    }

    .sub-tab-btn.active {
      background: var(--surface-raised);
      color: var(--primary);
      border-bottom: 2px solid var(--primary);
    }

    /* ALADDIN LAMP CHAMBER & SEQUENTIAL SCROLL EMERGENCE ANIMATION */
    .aladdin-chamber {
      position: relative;
      background: radial-gradient(circle at 50% 100%, rgba(245, 158, 11, 0.18), rgba(56, 189, 248, 0.06) 45%, transparent 72%);
      border: 1px solid var(--border);
      border-radius: 20px;
      padding: 40px 24px 34px;
      overflow: hidden;
      margin-bottom: 40px;
      transition: box-shadow 0.8s ease;
    }

    .aladdin-chamber.summon-step-1 {
      box-shadow: 0 0 45px rgba(245, 158, 11, 0.22);
    }

    .summon-control-bar {
      display: flex;
      justify-content: flex-end;
      margin-bottom: 12px;
      position: relative;
      z-index: 10;
    }

    .rub-lamp-btn {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 14px;
      border-radius: 20px;
      border: 1px solid var(--border-glow);
      background: rgba(245, 158, 11, 0.1);
      color: var(--primary);
      font-size: 0.78rem;
      font-family:var(--font-ui);
      font-weight: 700;
      cursor: pointer;
      transition: all 0.3s;
    }

    .rub-lamp-btn:hover {
      background: var(--primary);
      color: var(--primary-fg);
      transform: scale(1.04);
      box-shadow: 0 0 15px var(--primary-glow);
    }

    .genie-portals-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 28px;
      position: relative;
      z-index: 5;
      margin-bottom: 24px;
      min-height: 220px;
    }

    @media (max-width: 820px) {
      .genie-portals-wrapper {
        grid-template-columns: 1fr;
      }
    }

    .genie-card {
      background: var(--surface);
      border: 1px solid var(--border-glow);
      border-radius: 16px;
      padding: 20px;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), 0 0 25px rgba(245, 158, 11, 0.2);
      display: flex;
      gap: 18px;
      align-items: center;
      position: relative;
    }

    /* SCROLL ANIMATION: Start hidden down at the lamp's mouth */
    .genie-card-aladin {
      opacity: 0;
      transform: translate(30%, 160px) scale(0.12) rotate(-18deg);
      pointer-events: none;
      filter: blur(10px);
      transition: opacity 0.9s cubic-bezier(0.16, 1, 0.3, 1),
                  transform 1.25s cubic-bezier(0.175, 0.885, 0.32, 1.275),
                  filter 0.9s ease;
    }

    .genie-card-mohab {
      opacity: 0;
      transform: translate(-30%, 160px) scale(0.12) rotate(18deg);
      pointer-events: none;
      filter: blur(10px);
      transition: opacity 0.9s cubic-bezier(0.16, 1, 0.3, 1),
                  transform 1.25s cubic-bezier(0.175, 0.885, 0.32, 1.275),
                  filter 0.9s ease;
    }

    .genie-card.card-alt {
      border-color: var(--accent-glow);
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), 0 0 25px rgba(56, 189, 248, 0.2);
    }

    /* Step 1 Trigger: Aladin emerges first */
    .aladdin-chamber.summon-step-1 .genie-card-aladin {
      opacity: 1;
      transform: translate(0, 0) scale(1) rotate(0deg);
      pointer-events: auto;
      filter: blur(0px);
    }

    /* Step 2 Trigger: Mohab emerges second */
    .aladdin-chamber.summon-step-2 .genie-card-mohab {
      opacity: 1;
      transform: translate(0, 0) scale(1) rotate(0deg);
      pointer-events: auto;
      filter: blur(0px);
    }

    /* Step 3: Once fully emerged, both float gracefully */
    .aladdin-chamber.summon-complete .genie-card-aladin {
      animation: genieFloat 4.2s ease-in-out infinite;
    }

    .aladdin-chamber.summon-complete .genie-card-mohab {
      animation: genieFloat 4.2s ease-in-out infinite 2.1s;
    }

    .genie-img-wrap {
      width: 130px;
      height: 165px;
      flex-shrink: 0;
      border-radius: 14px;
      overflow: hidden;
      border: 3px solid #fbbf24;
      box-shadow: 0 0 20px rgba(251, 191, 36, 0.6);
      position: relative;
    }

    .genie-card.card-alt .genie-img-wrap {
      border-color: #38bdf8;
      box-shadow: 0 0 20px rgba(56, 189, 248, 0.6);
    }

    .genie-img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .genie-details {
      flex: 1;
    }

    .genie-title {
      font-size: 1.25rem;
      font-weight: 800;
      color: var(--fg);
      margin-bottom: 3px;
    }

    .genie-subtitle {
      font-size: 0.76rem;
      font-family:var(--font-ui);
      color: var(--primary);
      letter-spacing: 0.08em;
      margin-bottom: 8px;
    }

    .genie-card.card-alt .genie-subtitle {
      color: var(--accent);
    }

    .genie-desc {
      font-size: 0.88rem;
      color: var(--muted-fg);
      line-height: 1.48;
      font-style: italic;
    }

    .lamp-display-center {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      margin-top: 6px;
      position: relative;
      cursor: pointer;
    }

    .aladdin-lamp-svg {
      width: 135px;
      height: auto;
      filter: drop-shadow(0 0 20px rgba(245, 158, 11, 0.75));
      animation: lampGlow 3s infinite alternate;
      transition: transform 0.4s ease;
    }

    .lamp-display-center:hover .aladdin-lamp-svg {
      transform: scale(1.1) translateY(-4px);
      filter: drop-shadow(0 0 35px rgba(245, 158, 11, 0.95));
    }

    .lamp-burst {
      animation: lampBurstPulse 0.8s ease-out !important;
    }

    .smoke-path-left, .smoke-path-right {
      stroke-dasharray: 450;
      stroke-dashoffset: 450;
      opacity: 0;
      transition: stroke-dashoffset 1.4s ease-out, opacity 0.6s ease;
    }

    .aladdin-chamber.summon-step-1 .smoke-path-left {
      stroke-dashoffset: 0;
      opacity: 1;
    }

    .aladdin-chamber.summon-step-2 .smoke-path-right {
      stroke-dashoffset: 0;
      opacity: 1;
    }

    @keyframes lampBurstPulse {
      0% { transform: scale(1); filter: drop-shadow(0 0 15px rgba(245, 158, 11, 0.6)); }
      50% { transform: scale(1.22); filter: drop-shadow(0 0 45px rgba(254, 240, 138, 1)); }
      100% { transform: scale(1); filter: drop-shadow(0 0 20px rgba(245, 158, 11, 0.75)); }
    }

    @keyframes lampGlow {
      0% { transform: scale(1) translateY(0); filter: drop-shadow(0 0 16px rgba(245, 158, 11, 0.5)); }
      100% { transform: scale(1.05) translateY(-3px); filter: drop-shadow(0 0 30px rgba(245, 158, 11, 0.9)); }
    }

    @keyframes genieFloat {
      0%, 100% { transform: translateY(0px) rotate(0deg); }
      50% { transform: translateY(-7px) rotate(0.6deg); }
    }

    @keyframes pulseGlow {
      0%, 100% { box-shadow: 0 0 15px rgba(245, 158, 11, 0.3); }
      50% { box-shadow: 0 0 30px rgba(245, 158, 11, 0.6); }
    }

    mark.user-hl {
      background: var(--hl-color);
      color: var(--hl-text);
      padding: 1px 4px;
      border-radius: 4px;
      font-weight: 600;
    }

    .modal-backdrop {
      position: fixed;
      inset: 0;
      background: rgba(0, 0, 0, 0.75);
      backdrop-filter: blur(4px);
      z-index: 100;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 16px;
    }

    .modal-window {
      background: var(--surface);
      border: 1px solid var(--border-glow);
      border-radius: 16px;
      max-width: 820px;
      width: 100%;
      max-height: 90vh;
      overflow-y: auto;
      padding: 24px;
      box-shadow: var(--shadow-panel);
    }

    .in-test-desmos-window {
      position: fixed;
      top: 75px;
      right: 25px;
      width: 550px;
      max-width: calc(100vw - 32px);
      height: 530px;
      max-height: calc(100vh - 90px);
      z-index: 160;
      background: var(--surface);
      border: 1px solid var(--border-glow);
      border-radius: 14px;
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.65), 0 0 25px rgba(245, 158, 11, 0.2);
      display: none;
      flex-direction: column;
      overflow: hidden;
      resize: both;
      min-width: 320px;
      min-height: 360px;
    }

    @media (max-width: 768px) {
      .in-test-desmos-window {
        top: 65px !important;
        left: 12px !important;
        right: 12px !important;
        width: calc(100vw - 24px) !important;
        height: calc(100vh - 80px) !important;
        resize: none;
      }
    }

    svg {
      width: 18px;
      height: 18px;
      stroke-width: 2;
      stroke: currentColor;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
    }

    .grid-2col {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      align-items: center;
    }

    .grid-3col {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 18px;
    }

    @media (max-width: 900px) {
      .grid-2col {
        grid-template-columns: 1fr;
      }
    }

    .progress-bar-bg {
      height: 8px;
      background: var(--muted);
      border-radius: 9999px;
      overflow: hidden;
      margin: 12px 0 6px;
    }

    .progress-bar-fill {
      height: 100%;
      background: var(--gold-gradient);
      border-radius: 9999px;
      transition: width 0.4s ease;
    }

    .qb-card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 20px;
      margin-bottom: 18px;
    }

    .qb-card.solved-correct {
      border-left: 5px solid var(--success);
    }

    .qb-card.solved-wrong {
      border-left: 5px solid var(--destructive);
    }

    /* =========================================================================
       DUAL TIMER SYSTEM STYLES
       ========================================================================= */
    .dual-timer-box {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 6px 14px;
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 8px;
      transition: all 0.2s ease;
    }

    .dual-timer-box.warning {
      border-color: var(--destructive) !important;
      background: rgba(244, 63, 94, 0.12) !important;
      box-shadow: 0 0 12px rgba(244, 63, 94, 0.35);
      animation: timerWarningPulse 1.4s infinite;
    }

    @keyframes timerWarningPulse {
      0%, 100% { transform: scale(1); opacity: 1; }
      50% { transform: scale(1.02); opacity: 0.88; }
    }

    .dual-timer-text {
      font-family:var(--font-ui);
      font-weight: 700;
      font-size: 0.95rem;
      color: var(--primary);
      min-width: 80px;
      text-align: center;
    }

    .dual-timer-box.warning .dual-timer-text {
      color: var(--destructive) !important;
    }

    .dual-timer-toggle-btn {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 6px;
      padding: 3px 8px;
      font-size: 0.72rem;
      color: var(--muted-fg);
      cursor: pointer;
      font-family:var(--font-ui);
      transition: all 0.15s ease;
    }

    .dual-timer-toggle-btn:hover {
      border-color: var(--primary);
      color: var(--fg);
    }

    /* =========================================================================
       DYNAMIC SAT TARGET PACER & STEPPER FILTER STYLES
       ========================================================================= */
    .sat-target-pacer {
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 10px;
      padding: 10px 14px;
      margin-bottom: 14px;
      transition: all 0.25s ease;
    }

    .sat-target-pacer.optimal {
      border-color: rgba(16, 185, 129, 0.35);
    }

    .sat-target-pacer.warning {
      border-color: rgba(245, 158, 11, 0.45);
      background: linear-gradient(135deg, var(--surface-raised), rgba(245, 158, 11, 0.05));
    }

    .sat-target-pacer.danger {
      border-color: rgba(239, 68, 68, 0.55) !important;
      background: linear-gradient(135deg, var(--surface-raised), rgba(239, 68, 68, 0.08)) !important;
      box-shadow: 0 0 16px rgba(239, 68, 68, 0.15);
      animation: pacerAlertGlow 1.8s infinite;
    }

    @keyframes pacerAlertGlow {
      0%, 100% { border-color: rgba(239, 68, 68, 0.55); }
      50% { border-color: rgba(239, 68, 68, 0.85); box-shadow: 0 0 20px rgba(239, 68, 68, 0.28); }
    }

    .pacer-progress-track {
      width: 100%;
      height: 6px;
      background: rgba(255, 255, 255, 0.08);
      border-radius: 999px;
      margin-top: 8px;
      overflow: hidden;
    }

    .pacer-progress-fill {
      height: 100%;
      border-radius: 999px;
      transition: width 0.35s ease, background-color 0.35s ease;
      background: var(--success);
    }

    .stepper-filter-wrap {
      display: flex;
      align-items: center;
      gap: 6px;
      margin-bottom: 8px;
      flex-wrap: wrap;
    }

    .stepper-filter-btn {
      background: transparent;
      border: 1px solid var(--border);
      border-radius: 16px;
      padding: 3px 10px;
      font-size: 0.72rem;
      font-family:var(--font-ui);
      color: var(--muted-fg);
      cursor: pointer;
      transition: all 0.15s ease;
    }

    .stepper-filter-btn:hover {
      color: var(--fg);
      border-color: var(--border-glow);
    }

    .stepper-filter-btn.active {
      background: rgba(245, 158, 11, 0.12);
      border-color: var(--primary);
      color: var(--primary);
      font-weight: 700;
    }

    .matrix-filter-tabs {
      display: flex;
      gap: 8px;
      margin-bottom: 16px;
      flex-wrap: wrap;
    }

    .matrix-filter-tab {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 8px;
      padding: 6px 14px;
      font-size: 0.8rem;
      font-family:var(--font-ui);
      font-weight: 700;
      color: var(--muted-fg);
      cursor: pointer;
      transition: all 0.18s ease;
    }

    .matrix-filter-tab:hover {
      color: var(--fg);
    }

    .matrix-filter-tab.active {
      background: rgba(245, 158, 11, 0.12);
      border-color: var(--primary);
      color: var(--primary);
    }

    /* =========================================================================
       BLUEBOOK-STYLE REVIEW MATRIX & FLAGGING STYLES
       ========================================================================= */
    .review-matrix-container {
      max-width: 900px;
      margin: 0 auto;
      animation: fadeIn 0.25s ease-out;
    }

    .review-matrix-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
      gap: 12px;
      margin: 22px 0 32px 0;
    }

    @media (max-width: 600px) {
      .review-matrix-grid {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
        gap: 8px;
      }
    }

    .matrix-tile {
      background: var(--surface-card);
      border: 2px solid var(--border);
      border-radius: 10px;
      padding: 14px 10px;
      cursor: pointer;
      text-align: center;
      position: relative;
      transition: all 0.15s ease;
      user-select: none;
    }

    .matrix-tile:hover {
      transform: translateY(-2px);
      border-color: var(--primary);
      box-shadow: 0 4px 14px rgba(0, 0, 0, 0.25);
    }

    .matrix-tile.answered {
      background: rgba(56, 189, 248, 0.08);
      border-color: var(--accent);
    }

    .matrix-tile.unanswered {
      border-style: dashed;
      border-color: var(--border);
      opacity: 0.85;
    }

    .matrix-tile.flagged {
      border-color: var(--primary) !important;
    }

    .matrix-tile.flagged::before {
      content: '';
      position: absolute;
      top: 0;
      right: 0;
      width: 0;
      height: 0;
      border-top: 20px solid var(--primary);
      border-left: 20px solid transparent;
      border-top-right-radius: 8px;
    }

    .matrix-flag-icon {
      position: absolute;
      top: 2px;
      right: 3px;
      font-size: 0.72rem;
      color: var(--primary-fg);
      z-index: 2;
    }

    .matrix-q-num {
      font-size: 1.35rem;
      font-weight: 800;
      font-family:var(--font-ui);
      color: var(--fg);
      margin-bottom: 2px;
    }

    .matrix-status-label {
      font-size: 0.72rem;
      font-family:var(--font-ui);
      color: var(--muted-fg);
    }

    .matrix-tile.answered .matrix-status-label {
      color: var(--accent);
      font-weight: 600;
    }

    .matrix-tile.unanswered .matrix-status-label {
      color: var(--muted-fg);
    }

    /* =========================================================================
       GENIE'S ERROR VAULT — MISTAKE NOTEBOOK STYLES
       ========================================================================= */
    .mistake-card {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 14px;
      padding: 22px;
      margin-bottom: 20px;
      transition: all 0.2s ease;
      position: relative;
    }

    .mistake-card.unmastered {
      border-left: 5px solid var(--destructive);
    }

    .mistake-card.mastered {
      border-left: 5px solid var(--success);
    }

    .mistake-note-textarea {
      width: 100%;
      border-radius: 8px;
      border: 1px solid var(--border);
      background: var(--surface-card);
      color: var(--fg);
      padding: 10px 14px;
      font-size: 0.92rem;
      font-family: inherit;
      line-height: 1.5;
      resize: vertical;
      min-height: 72px;
      outline: none;
      transition: border-color 0.2s;
    }

    .mistake-note-textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 2px var(--primary-glow);
    }

    .mastery-badge {
      font-family:var(--font-ui);
      font-size: 0.75rem;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 6px;
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }

    .mastery-badge.unmastered {
      background: rgba(244, 63, 94, 0.14);
      color: var(--destructive);
      border: 1px solid rgba(244, 63, 94, 0.35);
    }

    .mastery-badge.mastered {
      background: rgba(16, 185, 129, 0.14);
      color: var(--success);
      border: 1px solid rgba(16, 185, 129, 0.35);
    }

    /* Explanation Tabs (Algebraic Method vs. Desmos Shortcut) */
    .exp-tabs-nav {
      display: flex;
      gap: 10px;
      border-bottom: 1px solid var(--border);
      margin-bottom: 12px;
      padding-bottom: 4px;
    }
    .exp-tab-btn {
      background: transparent;
      border: none;
      border-bottom: 2px solid transparent;
      padding: 6px 14px;
      font-family:var(--font-ui);
      font-weight: 700;
      font-size: 0.88rem;
      color: var(--muted-fg);
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: all 0.15s ease;
    }
    .exp-tab-btn:hover:not(.active) {
      color: var(--fg);
    }
    .exp-tab-btn.active-alg {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .exp-tab-btn.active-desmos {
      color: #38bdf8;
      border-bottom-color: #38bdf8;
    }
    .exp-panel {
      animation: fadeIn 0.2s ease;
    }

    /* Target Score Calculator Styles */
    .target-score-hero {
      background: linear-gradient(135deg, rgba(245, 158, 11, 0.08), rgba(56, 189, 248, 0.06));
      border: 1px solid var(--border-glow);
      border-radius: 16px;
      padding: 24px;
      margin-bottom: 24px;
    }
    .target-score-input-wrap {
      display: flex;
      align-items: center;
      gap: 20px;
      flex-wrap: wrap;
      margin-top: 14px;
    }
    .target-score-display {
      font-family:var(--font-ui);
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      text-shadow: 0 0 20px rgba(245, 158, 11, 0.35);
      line-height: 1;
      min-width: 140px;
    }
    .score-slider {
      flex: 1;
      min-width: 200px;
      accent-color: var(--primary);
      height: 8px;
      border-radius: 4px;
      cursor: pointer;
    }
    .benchmark-card {
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 12px;
      padding: 16px 20px;
      transition: transform 0.2s, border-color 0.2s;
    }
    .benchmark-card:hover {
      border-color: var(--border-glow);
      transform: translateY(-2px);
    }
    .domain-bar-bg {
      height: 8px;
      background: rgba(255, 255, 255, 0.08);
      border-radius: 4px;
      overflow: hidden;
      margin-top: 6px;
    }
    .domain-bar-fill {
      height: 100%;
      border-radius: 4px;
      transition: width 0.5s ease-out;
    }

    /* Toast */
    .toast {
      position: fixed;
      bottom: 24px;
      right: 24px;
      background: var(--surface);
      color: var(--fg);
      border: 1px solid var(--primary);
      padding: 14px 20px;
      border-radius: 10px;
      box-shadow: 0 8px 24px rgba(0,0,0,0.4), 0 0 12px var(--border-glow);
      z-index: 2000;
      display: flex;
      align-items: center;
      gap: 10px;
      transform: translateY(100px);
      opacity: 0;
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
      font-family:var(--font-ui);
      font-size: 0.88rem;
    }
    .toast.show {
      transform: translateY(0);
      opacity: 1;
    }

    /* Curriculum Video Lessons & Theater Modal */
    .video-lesson-card {
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 14px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
      position: relative;
    }
    .video-lesson-card:hover {
      border-color: var(--primary);
      transform: translateY(-2px);
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35), 0 0 16px rgba(245, 158, 11, 0.15);
    }
    .video-thumb-container {
      position: relative;
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #080c14;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      cursor: pointer;
    }
    .video-play-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: rgba(245, 158, 11, 0.92);
      color: #0c1017;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.25rem;
      padding-left: 3px;
      box-shadow: 0 0 16px rgba(245, 158, 11, 0.5);
      transition: transform 0.2s ease, background 0.2s ease;
    }
    .video-thumb-container:hover .video-play-btn {
      transform: scale(1.12);
      background: #fbbf24;
    }
    .video-theater-overlay {
      position: fixed;
      inset: 0;
      background: rgba(5, 8, 14, 0.88);
      backdrop-filter: blur(8px);
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 20px;
      z-index: 3000;
      animation: fadeIn 0.2s ease;
    }
    .video-theater-box {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 16px;
      width: 100%;
      max-width: 960px;
      max-height: 92vh;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 24px rgba(245, 158, 11, 0.2);
    }
    .video-player-frame {
      width: 100%;
      aspect-ratio: 16 / 9;
      background: #000;
      position: relative;
    }

    /* =========================================================================
       OFFICIAL COLLEGE BOARD SAT REFERENCE SHEET & VIDEO LINK STYLES
       ========================================================================= */
    .ref-modal-window {
      max-width: 1140px !important;
      width: 95vw !important;
      max-height: 92vh !important;
      padding: 24px 28px !important;
      border-radius: 18px !important;
      background: var(--surface) !important;
      border: 1px solid var(--border-glow) !important;
      box-shadow: 0 24px 60px rgba(0, 0, 0, 0.75), 0 0 30px rgba(245, 158, 11, 0.15) !important;
    }

    .ref-sheet-tabs {
      display: flex;
      gap: 10px;
      border-bottom: 1px solid var(--border);
      margin-bottom: 18px;
      padding-bottom: 4px;
    }

    .ref-tab-btn {
      background: transparent;
      border: none;
      border-bottom: 2px solid transparent;
      padding: 8px 16px;
      font-family:var(--font-ui);
      font-size: 0.92rem;
      font-weight: 700;
      color: var(--muted-fg);
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      gap: 7px;
    }
    .ref-tab-btn:hover {
      color: var(--fg);
    }
    .ref-tab-btn.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .ref-sheet-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 18px;
    }

    .ref-sheet-card {
      background: var(--surface-raised);
      border: 1px solid var(--border);
      border-radius: 14px;
      padding: 16px 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
    }
    .ref-sheet-card:hover {
      border-color: var(--primary);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
    }

    .ref-card-title {
      font-family:var(--font-ui);
      font-size: 0.95rem;
      font-weight: 700;
      color: var(--fg);
      margin-bottom: 10px;
      letter-spacing: 0.02em;
    }

    .ref-svg-wrap {
      width: 100%;
      height: 145px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: rgba(0, 0, 0, 0.28);
      border-radius: 10px;
      margin-bottom: 12px;
      padding: 8px 12px;
    }
    .ref-svg-wrap svg {
      width: 100%;
      height: 100%;
      max-height: 135px;
      display: block;
    }

    .ref-formula-box {
      font-family:var(--font-ui);
      font-size: 1.05rem;
      color: var(--primary);
      line-height: 1.45;
      margin-top: auto;
      width: 100%;
      padding-top: 8px;
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      font-weight: 600;
    }
    .ref-formula-box strong {
      font-weight: 700;
    }

    .ref-notes-banner {
      background: linear-gradient(135deg, rgba(245, 158, 11, 0.09), rgba(56, 189, 248, 0.05));
      border: 1px solid rgba(245, 158, 11, 0.3);
      border-radius: 12px;
      padding: 14px 18px;
      margin-top: 18px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .ref-notes-banner h4 {
      font-family:var(--font-ui);
      font-size: 0.9rem;
      color: var(--primary);
      margin: 0 0 4px 0;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .ref-notes-list {
      margin: 0;
      padding-left: 20px;
      font-size: 0.88rem;
      color: var(--fg);
      line-height: 1.6;
    }

    .exp-tab-video-btn {
      margin-left: auto;
      border: 1px solid var(--border-glow);
      border-radius: 8px;
      padding: 5px 12px;
      font-size: 0.8rem;
      font-family:var(--font-ui);
      font-weight: 700;
      color: var(--primary);
      background: rgba(245, 158, 11, 0.08);
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.18s ease;
    }
    .exp-tab-video-btn:hover {
      background: rgba(245, 158, 11, 0.2);
      border-color: var(--primary);
      transform: translateY(-1px);
    }

    /* =========================================================================
       P2 FEATURES: PACING & TIME-SPENT ANALYTICS (Test Review & Diagnostic)
       ========================================================================= */
    .pacing-analytics-card {
      background: var(--surface-raised);
      border: 1px solid var(--border-glow);
      border-radius: 14px;
      padding: 22px;
      margin: 24px 0;
      text-align: left;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    }

    .pacing-metric-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
      gap: 14px;
      margin: 16px 0;
    }

    .pacing-metric-item {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 10px;
      padding: 14px;
      text-align: center;
    }

    .pacing-metric-val {
      font-family:var(--font-ui);
      font-size: 1.6rem;
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 4px;
    }

    .pacing-metric-lbl {
      font-size: 0.74rem;
      color: var(--muted-fg);
      letter-spacing: 0.05em;
    }

    .time-sink-list {
      display: flex;
      flex-direction: column;
      gap: 8px;
      margin-top: 14px;
      max-height: 280px;
      overflow-y: auto;
    }

    .time-sink-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      background: rgba(0, 0, 0, 0.22);
      border: 1px solid var(--border);
      border-radius: 8px;
      padding: 10px 14px;
      font-size: 0.86rem;
      transition: all 0.15s ease;
    }
    .time-sink-item:hover {
      background: rgba(245, 158, 11, 0.05);
      border-color: var(--primary);
    }

    .time-sink-badge {
      font-family:var(--font-ui);
      font-size: 0.76rem;
      font-weight: 700;
      padding: 2px 8px;
      border-radius: 4px;
    }
    .time-sink-badge.trap {
      background: rgba(239, 68, 68, 0.15);
      color: #f87171;
      border: 1px solid rgba(239, 68, 68, 0.35);
    }
    .time-sink-badge.success {
      background: rgba(16, 185, 129, 0.15);
      color: #34d399;
      border: 1px solid rgba(16, 185, 129, 0.35);
    }

    /* =========================================================================
       P2 FEATURES: QUESTION OF THE DAY (QOTD)
       ========================================================================= */
    .qotd-container {
      background: linear-gradient(135deg, rgba(245, 158, 11, 0.08) 0%, rgba(56, 189, 248, 0.04) 50%, rgba(0, 0, 0, 0.4) 100%);
      border: 1.5px solid var(--border-glow);
      border-radius: 16px;
      padding: 24px;
      margin-bottom: 30px;
      box-shadow: 0 12px 36px rgba(0, 0, 0, 0.45), 0 0 24px rgba(245, 158, 11, 0.08);
      position: relative;
      overflow: hidden;
    }

    .qotd-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
      margin-bottom: 16px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      padding-bottom: 14px;
    }

    .qotd-streak-pill {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: rgba(245, 158, 11, 0.14);
      border: 1px solid rgba(245, 158, 11, 0.35);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 999px;
      font-size: 0.78rem;
      font-family:var(--font-ui);
      font-weight: 700;
    }

    .qotd-timer-pill {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: rgba(56, 189, 248, 0.12);
      border: 1px solid rgba(56, 189, 248, 0.35);
      color: #0369a1; /* 4.5:1+ on light backgrounds (was #38bdf8, 2.1:1) */
      padding: 4px 12px;
      border-radius: 999px;
      font-size: 0.78rem;
      font-family:var(--font-ui);
    }

    .qotd-choice-btn {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 12px 16px;
      border-radius: 10px;
      background: var(--surface);
      border: 1px solid var(--border);
      cursor: pointer;
      font-size: 0.95rem;
      color: var(--fg);
      text-align: left;
      transition: all 0.15s ease;
      width: 100%;
    }
    .qotd-choice-btn:hover:not(:disabled) {
      border-color: var(--primary);
      background: var(--surface-raised);
      transform: translateX(4px);
    }
    .qotd-choice-btn.selected-correct {
      border-color: var(--success);
      background: rgba(16, 185, 129, 0.12);
      color: var(--success);
    }
    .qotd-choice-btn.selected-wrong {
      border-color: var(--destructive);
      background: rgba(239, 68, 68, 0.12);
      color: var(--destructive);
    }

    /* =========================================================================
       P2 FEATURES: DESMOS KEYSTROKE PLAYBOOK
       ========================================================================= */
    .desmos-playbook-box {
      background: rgba(15, 23, 42, 0.75);
      border: 1px solid rgba(56, 189, 248, 0.28);
      border-radius: 12px;
      padding: 18px;
      margin-top: 10px;
      position: relative;
    }

    .desmos-playbook-title {
      font-family:var(--font-ui);
      font-size: 0.95rem;
      font-weight: 700;
      color: #38bdf8;
      display: flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 12px;
    }

    .desmos-step-item {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      padding: 8px 10px;
      border-radius: 8px;
      background: rgba(0, 0, 0, 0.25);
      margin-bottom: 8px;
      font-size: 0.9rem;
      line-height: 1.5;
    }
    .desmos-step-badge {
      font-family:var(--font-ui);
      font-size: 0.72rem;
      font-weight: 700;
      background: rgba(56, 189, 248, 0.18);
      color: #38bdf8;
      border: 1px solid rgba(56, 189, 248, 0.35);
      padding: 2px 7px;
      border-radius: 4px;
      white-space: nowrap;
      margin-top: 1px;
    }

    .desmos-key-pill {
      font-family:var(--font-ui);
      font-size: 0.82rem;
      font-weight: 600;
      background: rgba(245, 158, 11, 0.12);
      color: var(--primary);
      border: 1px solid rgba(245, 158, 11, 0.3);
      padding: 1px 6px;
      border-radius: 4px;
      letter-spacing: 0.02em;
    }




    /* ---- Docked in-test Desmos (Bluebook-style): the calculator sits beside the
       question instead of covering it. Desktop: full-height panel on the right,
       resizable from its left edge. Tablet/phone: bottom sheet. ---- */
    .desmos-dock-resizer { display: none; }
    body.desmos-docked main { margin-right: var(--desmos-dock-w, 42vw); transition: margin-right 0.15s ease; }
    body.desmos-docked .in-test-desmos-window {
      top: 0 !important; right: 0 !important; bottom: 0 !important; left: auto !important;
      width: var(--desmos-dock-w, 42vw) !important; height: 100vh !important; max-height: 100vh;
      max-width: 75vw; min-width: 320px; border-radius: 0; resize: none;
      border-width: 0 0 0 1px; box-shadow: -8px 0 30px rgba(0, 0, 0, 0.35);
    }
    body.desmos-docked .desmos-dock-resizer {
      display: block; position: absolute; left: -5px; top: 0; bottom: 0; width: 10px;
      cursor: col-resize; z-index: 3; touch-action: none;
    }
    body.desmos-docked .desmos-dock-resizer:hover, body.desmos-docked .desmos-dock-resizer.dragging {
      background: linear-gradient(90deg, transparent 3px, var(--primary) 3px, var(--primary) 6px, transparent 6px);
    }
    body.desmos-docked #in-test-desmos-header { cursor: default; }
    body.desmos-docked #in-test-desmos-floating-pill { right: calc(var(--desmos-dock-w, 42vw) + 24px) !important; }
    @media (max-width: 1024px) {
      body.desmos-docked main { margin-right: 0; padding-bottom: 52vh; }
      body.desmos-docked .in-test-desmos-window {
        top: auto !important; left: 0 !important; right: 0 !important; bottom: 0 !important;
        width: 100vw !important; height: 52vh !important; max-width: 100vw; min-width: 0;
        border-radius: 14px 14px 0 0; border-width: 1px 0 0 0;
      }
      body.desmos-docked .desmos-dock-resizer { display: none; }
      body.desmos-docked #in-test-desmos-floating-pill { right: 24px !important; bottom: calc(52vh + 12px) !important; }
    }
    @media (max-width: 1024px) {
      #desmos-dock-btn, #desmos-split-btn { display: none; }
    }
    @media (max-width: 600px) {
      #in-test-desmos-header .badge, #in-test-desmos-header button[title^="Reset"] { display: none; }
      #in-test-desmos-header strong { font-size: 0.85rem !important; }
    }

    /* ---- OnePrep / Bluebook parity (js/oneprep.js) ---- */
    .op-chip { display: inline-flex; align-items: center; padding: 3px 10px; border-radius: 999px; font-size: 0.78rem; font-weight: 600; background: var(--surface-raised); border: 1px solid var(--border); color: var(--fg); }
    .op-chip-id { font-family: var(--font-code, monospace); font-weight: 500; color: var(--muted-fg); }
    .op-diff-warm-up { color: var(--success); border-color: var(--success); }
    .op-diff-core { color: var(--primary); border-color: var(--border-glow); }
    .op-diff-stretch { color: var(--destructive); border-color: var(--destructive); }
    .op-switch { display: inline-flex; align-items: center; gap: 8px; margin-left: 6px; font-size: 0.82rem; font-weight: 600; cursor: pointer; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border); background: var(--surface); }
    .op-switch input { accent-color: var(--pencil, var(--primary)); width: 16px; height: 16px; }
    .op-report-btn { background: none; border: none; color: var(--muted-fg); font-size: 0.8rem; text-decoration: underline; cursor: pointer; padding: 4px; }
    .op-report-btn:hover { color: var(--fg); }
    .op-hint-wrap { margin: -10px 0 18px; }
    .op-hint-btn { font-size: 0.85rem; padding: 6px 14px; }
    .op-hint { margin-top: 10px; padding: 12px 14px; border-radius: 10px; background: var(--surface-raised); border-left: 3px solid var(--pencil, var(--primary)); line-height: 1.6; }
    .op-expr-list { display: grid; gap: 8px; margin-top: 12px; }
    .op-expr { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); }
    .op-expr code { flex: 1; min-width: 160px; font-size: 0.88rem; overflow-wrap: anywhere; }
    .op-mini { font-size: 0.78rem !important; padding: 4px 10px !important; }
    .op-drawer-backdrop { position: fixed; inset: 0; z-index: 400; background: rgba(14, 22, 38, 0.45); display: none; align-items: center; justify-content: center; padding: 16px; }
    .op-drawer { width: min(560px, 100%); max-height: 85vh; overflow: auto; background: var(--surface); color: var(--fg); border: 1px solid var(--border); border-radius: 16px; padding: 18px; box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3); display: grid; gap: 12px; }
    .op-drawer-head { display: flex; justify-content: space-between; align-items: center; }
    .op-icon-btn { background: none; border: 1px solid var(--border); border-radius: 8px; width: 32px; height: 32px; color: var(--fg); cursor: pointer; }
    .op-legend { display: flex; flex-wrap: wrap; gap: 12px; font-size: 0.8rem; color: var(--muted-fg); }
    .op-legend span { display: inline-flex; align-items: center; gap: 6px; }
    .op-swatch { width: 12px; height: 12px; border-radius: 3px; display: inline-block; border: 1px solid var(--border); }
    .op-nav-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(44px, 1fr)); gap: 8px; }
    .op-nav-tile { position: relative; height: 40px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--fg); font-weight: 700; cursor: pointer; }
    .op-unanswered { background: var(--surface); }
    .op-answered { background: rgba(47, 93, 179, 0.12); border-color: var(--accent); }
    .op-correct { background: var(--success-bg); border-color: var(--success); color: var(--success); }
    .op-incorrect { background: var(--destructive-bg); border-color: var(--destructive); color: var(--destructive); }
    .op-current { outline: 2px solid var(--pencil, var(--primary)); outline-offset: 1px; }
    .op-flag-dot, .op-flag-swatch { background: var(--pencil, var(--primary)); }
    .op-flag-dot { position: absolute; top: 3px; right: 3px; width: 7px; height: 7px; border-radius: 999px; }
    .op-field { display: grid; gap: 6px; font-size: 0.88rem; font-weight: 600; }
    .op-field select, .op-field textarea { width: 100%; padding: 9px 11px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--fg); font: inherit; font-weight: 400; }
    .op-pace { display: inline-flex; align-items: center; padding: 2px 9px; border-radius: 999px; font-size: 0.74rem; font-weight: 700; border: 1px solid var(--border); white-space: nowrap; }
    .op-pace-fast { color: var(--success); border-color: var(--success); background: var(--success-bg); }
    .op-pace-pace { color: var(--accent); border-color: var(--accent); }
    .op-pace-trap { color: var(--destructive); border-color: var(--destructive); background: var(--destructive-bg); }
    .op-pace-rushed { color: var(--primary); border-color: var(--border-glow); }
    .op-pace-skip { color: var(--muted-fg); }
    .op-pace-summary { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; margin-bottom: 14px; }
    .op-pace-col { display: grid; gap: 6px; font-size: 0.88rem; }
    .op-pace-row { display: flex; justify-content: space-between; gap: 10px; border-bottom: 1px solid var(--border); padding: 4px 0; }
    .op-pace-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 8px; }
    .op-pace-cell { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.85rem; }

/* Site footer (2026-10-15) */
.site-footer { margin: 48px auto 24px; padding: 18px 16px 0; max-width: 980px; border-top: 1px solid var(--border); display: grid; gap: 8px; font-size: 0.88rem; color: var(--muted-fg); text-align: center; }
.site-footer nav { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.site-footer a { color: var(--primary); text-decoration: none; }
.site-footer a:hover, .site-footer a:focus-visible { text-decoration: underline; }

/* Student hub: My week (2026-10-15) */
.hub-diag { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; padding: 16px 18px; margin-bottom: 14px; border-left: 4px solid var(--pencil, var(--primary)); }
.hub-announcements { display: grid; gap: 10px; margin-bottom: 14px; }
.hub-announcement { padding: 14px 16px; }
.hub-announcement.pinned { border-left: 4px solid var(--primary); }
.hub-ann-title { font-weight: 700; margin-bottom: 4px; }
.hub-ann-body { white-space: pre-line; line-height: 1.55; margin-bottom: 6px; }
.hub-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.hub-card { padding: 18px; }
.hub-card-head { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.hub-card-head h2 { font-size: 1.1rem; margin: 0; }
.hub-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 12px; }
.hub-stats div { background: var(--surface-raised); border-radius: 10px; padding: 8px; text-align: center; }
.hub-stats span { display: block; font-size: 1.25rem; font-weight: 800; }
.hub-stats small { color: var(--muted-fg); font-size: 0.72rem; }
.hub-tasks, .hub-hw { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.hub-tasks li, .hub-hw li { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 8px 10px; border: 1px solid var(--border); border-radius: 10px; }
.hub-tasks label { display: flex; gap: 8px; align-items: flex-start; cursor: pointer; flex: 1; }
.hub-tasks input { margin-top: 3px; width: 18px; height: 18px; }
.hub-tasks li.done span, .hub-hw li.done .hub-hw-title { text-decoration: line-through; color: var(--muted-fg); }
.hub-go { font-size: 0.8rem; padding: 4px 12px; white-space: nowrap; }
.hub-hw-title { font-weight: 600; }
.hub-hw-notes { margin-top: 4px; white-space: pre-line; }
.hub-hw-actions { display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end; }
.hub-overdue { color: var(--destructive, #c0392b); font-weight: 600; }
.hub-loading { padding: 16px; }

/* Touch & readability pass (ui-ux-pro-max checklist, 2026-10-15) */
.hub-stats small, .hub-card .small, .hub-card .muted-fg.small { font-size: 0.78rem; }
@media (max-width: 768px), (pointer: coarse) {
  .hub-go { min-height: 40px; padding: 8px 14px; }
  .hub-tasks input { width: 22px; height: 22px; }
  .hub-tasks label { min-height: 40px; align-items: center; }
  .stepper-filter-btn { min-height: 40px; padding: 8px 12px; }
  .dual-timer-toggle-btn { min-height: 40px; min-width: 40px; }
  .q-num-btn { min-width: 40px !important; height: 40px !important; }
  #view-practice .btn, #view-overview .btn { min-height: 40px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}

/* Question video explanations (2026-10-15) */
.op-video-drawer { width: min(860px, 100%); }
.op-video-frame { position: relative; width: 100%; aspect-ratio: 16 / 9; background: #000; border-radius: 12px; overflow: hidden; }
.op-video-frame iframe, .op-video-frame video { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.op-video-frame p { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; color: #fff; padding: 16px; text-align: center; }
.op-video-frame a { color: #F2A900; }

/* Goals & badges (2026-10-15) */
.hub-goal { display: flex; gap: 14px; align-items: center; margin-bottom: 12px; }
.hub-goal-ring { --p: 0; flex-shrink: 0; width: 72px; height: 72px; border-radius: 50%; display: grid; place-items: center;
  background: conic-gradient(var(--primary) calc(var(--p) * 1%), var(--surface-raised) 0); }
.hub-goal-ring span { width: 56px; height: 56px; border-radius: 50%; background: var(--surface); display: grid; place-items: center; font-weight: 800; font-size: 0.9rem; }
.hub-goal-pick { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.hub-badges { display: flex; flex-wrap: wrap; gap: 6px; }
.hub-badge { display: inline-flex; gap: 6px; align-items: center; padding: 6px 10px; border-radius: 999px; border: 1px solid var(--border); font-size: 0.85rem; font-weight: 600; }
.hub-badge.earned { background: var(--surface-raised); border-color: var(--pencil, var(--primary)); }
.hub-next { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.hub-next li { display: flex; gap: 8px; align-items: center; font-size: 0.88rem; }
.hub-next li span:nth-child(2) { flex: 1; }

/* Leaderboard + plug-into-Desmos (2026-10-15) */
.hub-board { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; }
.hub-board li { display: grid; grid-template-columns: 40px 1fr auto; gap: 8px; align-items: center; padding: 8px 10px; border-radius: 10px; }
.hub-board li:nth-child(odd) { background: var(--surface-raised); }
.hub-board li.me { outline: 2px solid var(--pencil, var(--primary)); }
.hub-board-rank { font-weight: 800; text-align: center; }
.hub-board-name { font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.op-plug-btn { margin: 10px 0 6px; min-height: 40px; }