/* ─── Algorithms section ─────────────────────────────────────────── */
        .algo-tabs {
            display: flex;
            gap: 2px;
            border-bottom: 1px solid var(--border);
            margin-bottom: 32px;
            overflow-x: auto;
        }

        .algo-tab {
            padding: 10px 20px;
            font-size: .85rem;
            font-weight: 500;
            color: var(--muted);
            cursor: pointer;
            border-bottom: 2px solid transparent;
            white-space: nowrap;
            transition: color .2s, border-color .2s;
            background: none;
            border-top: none;
            border-left: none;
            border-right: none;
        }

        .algo-tab:hover {
            color: var(--text);
        }

        .algo-tab.active {
            color: var(--teal);
            border-bottom-color: var(--teal);
        }

        .algo-panel {
            display: none;
        }

        .algo-panel.active {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 32px;
            align-items: start;
        }

        .algo-desc h3 {
            font-size: 1.2rem;
            font-weight: 700;
            margin-bottom: 12px;
        }

        .algo-desc p {
            color: var(--muted);
            line-height: 1.8;
            margin-bottom: 16px;
            font-size: .92rem;
        }

        .algo-desc ul {
            padding-left: 20px;
            color: var(--muted);
            font-size: .88rem;
            line-height: 1.9;
        }

        .algo-desc li::marker {
            color: var(--teal);
        }

        .math-card {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 12px;
            overflow: hidden;
        }

        .math-header {
            background: var(--surface2);
            padding: 10px 16px;
            font-size: .72rem;
            font-weight: 600;
            letter-spacing: .06em;
            text-transform: uppercase;
            color: var(--muted);
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .math-lang {
            color: var(--teal);
            font-family: var(--mono);
        }

        .math-body {
            padding: 20px 18px;
            font-size: .88rem;
            line-height: 2.2;
            color: var(--purple);
        }

        .code-body {
            padding: 0;
            overflow-x: auto;
        }

        .code-body pre {
            padding: 18px 18px;
            font-family: var(--mono);
            font-size: .78rem;
            line-height: 1.7;
            color: #a8d8a8;
            background: transparent;
        }

        .kw {
            color: #ff79c6;
        }

        .fn {
            color: #8be9fd;
        }

        .str {
            color: #f1fa8c;
        }

        .cm {
            color: #6272a4;
        }

        .var {
            color: #bd93f9;
        }

        /* ─── Code / Codebase section ────────────────────────────────────── */
        .module-list {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .module-row {
            display: grid;
            grid-template-columns: 200px 1fr auto;
            align-items: center;
            gap: 20px;
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 10px;
            padding: 14px 20px;
            transition: border-color .2s;
        }

        .module-row:hover {
            border-color: var(--teal2);
        }

        .module-file {
            font-family: var(--mono);
            font-size: .78rem;
            color: var(--teal);
        }

        .module-desc {
            font-size: .84rem;
            color: var(--muted);
            line-height: 1.5;
        }

        .module-tags {
            display: flex;
            gap: 6px;
            flex-wrap: wrap;
            justify-content: flex-end;
        }

        .tag {
            background: rgba(57, 208, 240, .08);
            color: var(--teal);
            border: 1px solid rgba(57, 208, 240, .2);
            border-radius: 4px;
            padding: 2px 8px;
            font-size: .7rem;
            font-family: var(--mono);
            white-space: nowrap;
        }

        .tag-purple {
            background: rgba(188, 140, 255, .08);
            color: var(--purple);
            border-color: rgba(188, 140, 255, .2);
        }

        .tag-orange {
            background: rgba(240, 136, 62, .08);
            color: var(--orange);
            border-color: rgba(240, 136, 62, .2);
        }

        .tag-green {
            background: rgba(63, 185, 80, .08);
            color: var(--green);
            border-color: rgba(63, 185, 80, .2);
        }

        /* ─── CLI section ────────────────────────────────────────────────── */
        .terminal {
            background: #0d1117;
            border: 1px solid var(--border);
            border-radius: 12px;
            overflow: hidden;
        }

        .terminal-bar {
            background: var(--surface2);
            padding: 10px 16px;
            display: flex;
            align-items: center;
            gap: 8px;
            border-bottom: 1px solid var(--border);
        }

        .t-dot {
            width: 12px;
            height: 12px;
            border-radius: 50%;
        }

        .t-red {
            background: #ff6058;
        }

        .t-yellow {
            background: #ffbd2e;
        }

        .t-green {
            background: #28c940;
        }

        .t-title {
            font-size: .78rem;
            color: var(--muted);
            margin-left: 8px;
            font-family: var(--mono);
        }

        .terminal-body {
            padding: 20px 24px;
            font-family: var(--mono);
            font-size: .82rem;
            line-height: 2;
        }

        .t-prompt {
            color: #3fb950;
        }

        .t-cmd {
            color: #e6edf3;
        }

        .t-out {
            color: var(--muted);
        }

        .t-hi {
            color: var(--teal);
        }

        .t-blank {
            display: block;
            margin: 4px 0;
        }

        /* ─── FAQ / Interview ────────────────────────────────────────────── */
        .faq-list {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .faq-item {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 12px;
            overflow: hidden;
        }

        .faq-q {
            padding: 18px 22px;
            font-size: .92rem;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            user-select: none;
            transition: background .2s;
        }

        .faq-q:hover {
            background: var(--surface2);
        }

        .faq-q::after {
            content: '+';
            color: var(--teal);
            font-size: 1.2rem;
            transition: transform .25s;
        }

        .faq-item.open .faq-q::after {
            transform: rotate(45deg);
        }

        .faq-a {
            max-height: 0;
            overflow: hidden;
            transition: max-height .3s ease, padding .3s;
            padding: 0 22px;
            color: var(--muted);
            font-size: .88rem;
            line-height: 1.8;
        }

        .faq-item.open .faq-a {
            max-height: 400px;
            padding: 0 22px 18px;
        }

        .faq-a strong {
            color: var(--text);
        }