:root {
            /* Indigo Theme override */
            --color-indigo: #6366f1;
            --color-indigo-glow: rgba(99, 102, 241, 0.35);
            --color-accent: #6366f1;
            --color-accent-glow: rgba(99, 102, 241, 0.35);

            --color-slice: #10b981; /* Emerald for slices */
            --color-runner: #38bdf8; /* Cyan for runner */
            --color-asymptote: #ffb000; /* Amber for limit line */
        }

        .sidebar-drawer .syllabus-item.active a {
            background: var(--color-accent) !important;
            box-shadow: 0 4px 20px var(--color-accent-glow) !important;
            color: var(--bg-color) !important;
        }

        .sidebar-drawer .syllabus-item.active a .syllabus-title {
            color: var(--bg-color) !important;
        }

        .sidebar-drawer .syllabus-item.active a .syllabus-desc {
            color: rgba(0, 0, 0, 0.6) !important;
        }

        section {
            margin-bottom: 6rem;
            scroll-margin-top: 2rem;
        }

        .section-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 1.75rem;
        }

        .section-tag {
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.8rem;
            color: var(--color-indigo);
            background: rgba(99, 102, 241, 0.1);
            padding: 4px 10px;
            border-radius: 6px;
            border: 1px solid rgba(99, 102, 241, 0.2);
            text-shadow: 0 0 5px var(--color-indigo-glow);
        }

        .section-header h2 {
            font-size: 1.75rem;
            font-weight: 700;
        }

        .section-intro {
            color: var(--text-muted);
            margin-bottom: 2rem;
            line-height: 1.6;
            font-size: 1rem;
            max-width: 850px;
        }

        .equation-box {
            font-family: 'JetBrains Mono', monospace;
            font-size: 1.35rem;
            font-weight: 700;
            text-align: center;
            padding: 1.25rem;
            background: rgba(255, 255, 255, 0.015);
            border-radius: 16px;
            border: 1px dashed rgba(255, 255, 255, 0.06);
            margin-bottom: 1.5rem;
            color: var(--text-color);
        }

        .slider-group {
            display: flex;
            flex-direction: column;
            gap: 1.25rem;
            margin-bottom: 1.5rem;
        }

        .slider-row {
            display: flex;
            flex-direction: column;
            gap: 6px;
        }

        .slider-label {
            display: flex;
            justify-content: space-between;
            font-size: 0.9rem;
            font-weight: 500;
            color: var(--text-muted);
        }

        .slider-row input[type="range"] {
            -webkit-appearance: none;
            width: 100%;
            height: 6px;
            background: rgba(255, 255, 255, 0.08);
            border-radius: 3px;
            outline: none;
            margin: 8px 0;
        }

        .slider-row input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background: var(--color-indigo);
            cursor: pointer;
            box-shadow: 0 0 8px var(--color-indigo-glow);
        }

        .formula-steps {
            background: rgba(0, 0, 0, 0.2);
            border-radius: 12px;
            padding: 1.25rem;
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.85rem;
            line-height: 1.6;
            color: var(--text-color);
            border: 1px solid var(--card-border);
        }

        .btn-preset {
            background: rgba(255, 255, 255, 0.02);
            color: var(--text-muted);
            border: 1px solid var(--card-border);
            padding: 6px 12px;
            border-radius: 8px;
            font-size: 0.85rem;
            cursor: pointer;
            transition: all var(--transition-speed) ease;
        }

        .btn-preset:hover, .btn-preset.active {
            color: var(--text-color);
            background: rgba(255, 255, 255, 0.06);
            border-color: rgba(255, 255, 255, 0.15);
        }

        .presets-grid {
            display: flex;
            gap: 8px;
            margin-bottom: 1.5rem;
            flex-wrap: wrap;
        }

        .btn-mode {
            flex: 1;
            padding: 0.6rem;
            font-family: 'Outfit', sans-serif;
            font-weight: 600;
            background: rgba(255, 255, 255, 0.02);
            color: var(--text-muted);
            border: 1px solid var(--card-border);
            border-radius: 8px;
            cursor: pointer;
            transition: all var(--transition-speed) ease;
            font-size: 0.85rem;
            text-align: center;
        }

        .btn-mode.active {
            background: rgba(99, 102, 241, 0.15);
            color: var(--color-indigo);
            border-color: rgba(99, 102, 241, 0.3);
        }

        .quiz-option {
            background: rgba(255, 255, 255, 0.015);
            border: 1px solid var(--card-border);
            border-radius: 12px;
            padding: 1rem 1.25rem;
            margin-bottom: 0.75rem;
            cursor: pointer;
            transition: all var(--transition-speed) ease;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .quiz-option:hover {
            background: rgba(255, 255, 255, 0.04);
            border-color: rgba(255, 255, 255, 0.1);
            transform: translateX(4px);
        }

        .quiz-option.correct {
            background: rgba(16, 185, 129, 0.08);
            border-color: rgba(16, 185, 129, 0.3);
            color: #10b981;
        }

        .quiz-option.incorrect {
            background: rgba(244, 63, 94, 0.08);
            border-color: rgba(244, 63, 94, 0.3);
            color: #f43f5e;
        }

        .quiz-feedback {
            margin-top: 1rem;
            padding: 1rem;
            border-radius: 12px;
            background: rgba(255, 255, 255, 0.02);
            border: 1px solid var(--card-border);
            font-size: 0.9rem;
            line-height: 1.5;
            display: none;
        }

        .status-badge {
            display: inline-block;
            padding: 4px 10px;
            border-radius: 6px;
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.8rem;
            font-weight: 700;
        }

        .status-badge.converge {
            background: rgba(16, 185, 129, 0.12);
            color: #10b981;
            border: 1px solid rgba(16, 185, 129, 0.25);
        }

        .status-badge.diverge {
            background: rgba(244, 63, 94, 0.12);
            color: #f43f5e;
            border: 1px solid rgba(244, 63, 94, 0.25);
        }