/* Self-hosted fonts — see public/assets/fonts/FONT_LICENSE.md. Never loaded from a CDN. */
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-400-bengali.woff2') format('woff2');
    unicode-range: U+0951-0952, U+0964-0965, U+0980-09FE, U+1CD0, U+1CD2, U+1CD5-1CD6, U+1CD8, U+1CE1, U+1CEA, U+1CED, U+1CF2, U+1CF5-1CF7, U+200C-200D, U+20B9, U+25CC, U+A8F1;
}
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-400-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+2000-206F, U+20AC, U+2122;
}
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 600;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-600-bengali.woff2') format('woff2');
    unicode-range: U+0951-0952, U+0964-0965, U+0980-09FE, U+1CD0, U+1CD2, U+1CD5-1CD6, U+1CD8, U+1CE1, U+1CEA, U+1CED, U+1CF2, U+1CF5-1CF7, U+200C-200D, U+20B9, U+25CC, U+A8F1;
}
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 600;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-600-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+2000-206F, U+20AC, U+2122;
}
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 700;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-700-bengali.woff2') format('woff2');
    unicode-range: U+0951-0952, U+0964-0965, U+0980-09FE, U+1CD0, U+1CD2, U+1CD5-1CD6, U+1CD8, U+1CE1, U+1CEA, U+1CED, U+1CF2, U+1CF5-1CF7, U+200C-200D, U+20B9, U+25CC, U+A8F1;
}
@font-face {
    font-family: 'Hind Siliguri';
    font-style: normal;
    font-weight: 700;
    font-display: swap;
    src: url('/assets/fonts/hind-siliguri/hind-siliguri-700-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+2000-206F, U+20AC, U+2122;
}
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 400 700;
    font-display: swap;
    src: url('/assets/fonts/inter/inter-variable-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+2000-206F, U+20AC, U+2122;
}
@font-face {
    font-family: 'JetBrains Mono';
    font-style: normal;
    font-weight: 400 500;
    font-display: swap;
    src: url('/assets/fonts/jetbrains-mono/jetbrains-mono-variable-latin.woff2') format('woff2');
    unicode-range: U+0000-00FF, U+2000-206F, U+20AC, U+2122;
}

:root {
    --bg-primary: #0D1117;
    --surface: #161B22;
    --surface-raised: #1C232C;
    --border: #30363D;
    --text-primary: #E6EDF3;
    --text-muted: #8B949E;
    --accent-terminal: #39D353;
    --accent-terminal-hover: #2EA043;
    --accent-gold: #F5A623;
    --danger: #F85149;
    --info: #58A6FF;
    --form-surface: #FFFFFF;
    --form-text: #0D1117;
    --on-accent-terminal: #04150a;
    --on-danger: #2a0704;

    /* Motion: critically-damped (no overshoot) is the default everywhere —
       Apple's guidance for routine UI. --ease-spring (a touch of overshoot)
       is reserved for reward/delight moments only (XP pop, node complete,
       card entrance) — never for ordinary hover/press feedback. */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
    --duration-fast: 120ms;
    --duration-base: 250ms;
    --duration-slow: 450ms;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background:
        radial-gradient(ellipse 900px 500px at 15% -10%, rgba(57, 211, 83, 0.07), transparent 60%),
        radial-gradient(ellipse 700px 500px at 100% 0%, rgba(245, 166, 35, 0.05), transparent 55%),
        var(--bg-primary);
    background-attachment: fixed;
    color: var(--text-primary);
    font-family: 'Inter', 'Hind Siliguri', system-ui, sans-serif;
    line-height: 1.6;
}

code, pre, .code-sample, .code-editor { font-family: 'JetBrains Mono', monospace; }

/* ── Typography scale — size-specific tracking/leading per Apple's rule:
   tight leading + negative tracking as text grows large; body stays near 0. ── */
h1, h2, h3 { font-weight: 700; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 0.5em; }
h1 { font-size: clamp(1.75rem, 1.3rem + 2vw, 2.75rem); }
h2 { font-size: clamp(1.25rem, 1.1rem + 1vw, 1.625rem); letter-spacing: -0.01em; }
h3 { font-size: 1.125rem; letter-spacing: -0.005em; }
p { letter-spacing: 0; }

a { color: var(--accent-terminal); transition: color var(--duration-fast) var(--ease-out); }
a:hover { color: var(--accent-terminal-hover); }

/* Deliberate, visible focus ring — reinforces the terminal-cursor motif
   instead of leaving keyboard users with an unstyled browser default. */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--accent-terminal);
    outline-offset: 2px;
    transition: outline-offset var(--duration-fast) var(--ease-out);
}

/* 44px minimum touch target (WCAG 2.5.5) on every text-entry control across
   both the public site and admin — set once here rather than per-form. */
input:not([type="checkbox"]):not([type="radio"]),
select,
button {
    min-height: 44px;
}

input, select, textarea {
    transition: border-color var(--duration-fast) var(--ease-out), box-shadow var(--duration-fast) var(--ease-out);
}
input:focus, select:focus, textarea:focus {
    border-color: var(--accent-terminal) !important;
    box-shadow: 0 0 0 3px rgba(57, 211, 83, 0.15);
}

/* ── Nav: translucent floating material, content scrolls under it ── */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: rgba(13, 17, 23, 0.72);
    backdrop-filter: blur(16px) saturate(140%);
    -webkit-backdrop-filter: blur(16px) saturate(140%);
    border-bottom: 1px solid var(--border);
}

.brand {
    font-weight: 700;
    text-decoration: none;
    color: var(--text-primary);
    display: inline-flex;
    align-items: baseline;
    gap: 0.15em;
}
.brand-bn { color: var(--text-muted); font-weight: 400; }
/* Terminal cursor flourish — the one signature motion touch on brand mark. */
.brand::after {
    content: '';
    display: inline-block;
    width: 0.5em;
    height: 1em;
    margin-left: 0.05em;
    background: var(--accent-terminal);
    animation: cursor-blink 1.1s steps(1) infinite;
}

.nav-links { display: flex; align-items: center; flex-wrap: wrap; gap: 1.25rem; }
.nav-links a { color: var(--text-muted); text-decoration: none; font-size: 0.9375rem; position: relative; }
.nav-links a:not(.btn) { padding-bottom: 2px; }
.nav-links a:not(.btn)::after {
    content: '';
    position: absolute;
    left: 0; right: 100%; bottom: 0;
    height: 2px;
    background: var(--accent-terminal);
    transition: right var(--duration-base) var(--ease-out);
}
.nav-links a:not(.btn):hover { color: var(--text-primary); }
.nav-links a:not(.btn):hover::after { right: 0; }
.inline-form { display: inline; }

.site-main { min-height: 60vh; padding: 2rem 1.5rem; max-width: 960px; margin: 0 auto; animation: fade-up var(--duration-slow) var(--ease-out) both; }

.site-footer {
    border-top: 1px solid var(--border);
    padding: 1.5rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}
.footer-links a { color: var(--text-muted); }

.error-page { text-align: center; padding: 4rem 1rem; }
.error-page h1 { font-size: 3rem; color: var(--accent-gold); }

/* ── Buttons: instant press feedback (respond on the press, not release),
   hover lift, no overshoot — routine UI stays critically damped. ── */
.btn {
    display: inline-block;
    padding: 0.6rem 1.25rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    transition: transform var(--duration-fast) var(--ease-out),
                box-shadow var(--duration-base) var(--ease-out),
                background-color var(--duration-fast) var(--ease-out);
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(0.97); transition-duration: 60ms; }

.btn-price { background: var(--surface-raised); color: var(--accent-gold); border: 1px solid var(--border); }
.btn-price:hover { box-shadow: 0 4px 16px rgba(245, 166, 35, 0.18); }

/* Every "৳2.78/day" mention (nav CTA, hero, subscribe box, billing notice,
   terms) renders through price_line() — one badge, everywhere at once. */
.price-amount {
    display: inline-flex;
    align-items: baseline;
    font-weight: 800;
    font-variant-numeric: tabular-nums;
    color: var(--accent-gold);
    background: rgba(245, 166, 35, 0.16);
    padding: 0.05em 0.4em;
    border-radius: 999px;
    animation: gold-pulse 2.8s var(--ease-out) infinite;
}
.btn-accent { background: var(--accent-terminal); color: var(--on-accent-terminal); }
.btn-accent:hover { background: var(--accent-terminal-hover); color: var(--on-accent-terminal); box-shadow: 0 4px 20px rgba(57, 211, 83, 0.28); }
.btn-link { background: none; color: var(--info); text-decoration: underline; padding: 0; min-height: auto; }
.btn-link:hover { transform: none; }
.btn-danger { background: var(--danger); color: var(--on-danger); }
.btn-danger:hover { box-shadow: 0 4px 20px rgba(248, 81, 73, 0.28); }
.btn-ghost { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.btn-ghost:hover { color: var(--text-primary); border-color: var(--text-muted); }

.account-status, .unsubscribe-confirm { text-align: center; }
.status-badge { padding: 1rem; border-radius: 8px; background: var(--surface); margin: 1rem 0; animation: fade-up var(--duration-base) var(--ease-out) both; }
.status-active { color: var(--accent-terminal); }
.status-grace { color: var(--accent-gold); }
.status-expired, .status-unsubscribed { color: var(--text-muted); }
.unsubscribe-link { color: var(--danger); display: inline-block; margin-top: 1rem; }

/* ── Cards: hover lift + glow, staggered entrance so a grid feels alive
   arriving rather than just appearing. ── */
.track-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 1rem; margin-top: 1.5rem; }
.track-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.25rem;
    text-decoration: none;
    color: var(--text-primary);
    display: block;
    transition: transform var(--duration-base) var(--ease-out),
                border-color var(--duration-base) var(--ease-out),
                box-shadow var(--duration-base) var(--ease-out);
    animation: fade-up var(--duration-slow) var(--ease-out) both;
}
.track-card:hover { border-color: var(--accent-terminal); transform: translateY(-3px); box-shadow: 0 10px 30px -10px rgba(57, 211, 83, 0.25); }
.track-card:active { transform: translateY(-1px) scale(0.99); }
.track-card h2 { margin: 0 0 0.25rem; font-size: 1.1rem; }
.track-en { color: var(--text-muted); font-size: 0.8125rem; margin: 0; }

/* ── Skill tree: staggered reveal per node, partial/current node pulses
   gold — this is literally what BUILD-SPEC's token table specs for
   accent-gold ("current staircase step, pulse") and was never wired up. ── */
.skill-tree { margin: 1.5rem 0; }
.skill-tree-track { font-weight: 700; color: var(--text-muted); }
.skill-tree-list { list-style: none; padding-left: 0.5rem; margin: 0; border-left: 2px solid var(--border); }
.skill-node {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.5rem 0 0.5rem 1rem;
    border-radius: 6px;
    transition: background-color var(--duration-base) var(--ease-out);
    animation: node-in var(--duration-slow) var(--ease-out) both;
}
.skill-node:hover { background: rgba(255, 255, 255, 0.03); }
.skill-node-link {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    width: 100%;
    color: inherit;
    text-decoration: none;
    cursor: pointer;
}
.skill-node-link:hover .skill-title { color: var(--accent-terminal); }
.skill-node-link:focus-visible { outline: 2px solid var(--accent-terminal); outline-offset: 2px; border-radius: 4px; }
.skill-tree-list .skill-node:nth-child(1) { animation-delay: 40ms; }
.skill-tree-list .skill-node:nth-child(2) { animation-delay: 80ms; }
.skill-tree-list .skill-node:nth-child(3) { animation-delay: 120ms; }
.skill-tree-list .skill-node:nth-child(4) { animation-delay: 160ms; }
.skill-tree-list .skill-node:nth-child(5) { animation-delay: 200ms; }
.skill-tree-list .skill-node:nth-child(6) { animation-delay: 240ms; }
.skill-icon { width: 1.75rem; text-align: center; font-weight: 700; flex-shrink: 0; }
.skill-icon-complete { color: var(--accent-terminal); }
.skill-icon-partial { color: var(--accent-gold); animation: gold-pulse 2.2s var(--ease-out) infinite; border-radius: 50%; }
.skill-icon-locked, .skill-icon-not-started { color: var(--text-muted); }

/* Quiet, one-time explainer for the ✓/%/🔒 vocabulary — new coders shouldn't
   have to guess what a bare percentage or lock icon means. */
.skill-legend { display: flex; flex-wrap: wrap; gap: 0.4rem 1.25rem; list-style: none; padding: 0; margin: 0.5rem 0 1.25rem; font-size: 0.8125rem; color: var(--text-muted); }
.skill-legend li { display: inline-flex; align-items: center; gap: 0.35rem; }
.skill-legend-dot { display: inline-block; width: 1.5rem; text-align: center; font-weight: 700; }
.skill-legend-dot.is-complete { color: var(--accent-terminal); }
.skill-legend-dot.is-partial { color: var(--accent-gold); }

.module-page { max-width: 720px; margin: 0 auto; }
.lesson-list { list-style: none; margin: 1.5rem 0 0; padding: 0; display: flex; flex-direction: column; gap: 0.5rem; }
.lesson-list-item {
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    animation: fade-up var(--duration-base) var(--ease-out) both;
}
.lesson-list-item a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1rem;
    color: inherit;
    text-decoration: none;
}
.lesson-list-item a:hover .lesson-list-title { color: var(--accent-terminal); }
.lesson-status-icon { width: 1.5rem; text-align: center; flex-shrink: 0; color: var(--text-muted); }
.lesson-list-item.status-completed .lesson-status-icon { color: var(--accent-terminal); }
.lesson-list-item.status-in_progress .lesson-status-icon { color: var(--accent-gold); }
.lesson-list-title { flex: 1; font-weight: 600; }
.lesson-list-status { font-size: 0.8125rem; color: var(--text-muted); }

.quiz-result-banner {
    padding: 1.25rem 1.5rem;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--surface);
    margin: 1rem 0 1.5rem;
    animation: fade-up var(--duration-base) var(--ease-out) both;
}
.quiz-result-banner.is-passed { border-color: var(--accent-terminal); }
.quiz-result-banner.is-failed { border-color: var(--accent-gold); }
.quiz-result-score { font-size: 1.25rem; font-weight: 700; margin: 0 0 0.35rem; }
.quiz-result-banner.is-passed .quiz-result-score { color: var(--accent-terminal); }
.quiz-result-banner.is-failed .quiz-result-score { color: var(--accent-gold); }

.quiz-result-list { list-style: none; margin: 0 0 1.5rem; padding: 0; display: flex; flex-direction: column; gap: 1rem; }
.quiz-result-question {
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem 1.1rem;
    background: var(--surface);
}
.quiz-result-question.is-correct { border-left: 3px solid var(--accent-terminal); }
.quiz-result-question.is-incorrect { border-left: 3px solid var(--danger); }
.quiz-result-question-text { display: flex; align-items: flex-start; gap: 0.5rem; font-weight: 600; margin: 0 0 0.5rem; }
.quiz-result-icon { flex-shrink: 0; font-weight: 700; }
.quiz-result-question.is-correct .quiz-result-icon { color: var(--accent-terminal); }
.quiz-result-question.is-incorrect .quiz-result-icon { color: var(--danger); }
.quiz-result-options { list-style: none; margin: 0 0 0.5rem; padding: 0; display: flex; flex-direction: column; gap: 0.35rem; }
.quiz-result-options li { padding: 0.4rem 0.6rem; border-radius: 6px; font-size: 0.9375rem; }
.quiz-result-options li.is-correct-option { background: rgba(57, 211, 83, 0.12); color: var(--accent-terminal); }
.quiz-result-options li.is-wrong-choice { background: rgba(248, 81, 73, 0.12); color: var(--danger); }
.quiz-result-tag { font-size: 0.75rem; font-weight: 700; margin-left: 0.5rem; text-transform: uppercase; letter-spacing: 0.02em; }
.quiz-result-tag-wrong { color: var(--danger); }
.quiz-result-explanation { font-size: 0.9375rem; color: var(--text-muted); margin: 0.5rem 0 0; padding-top: 0.5rem; border-top: 1px dashed var(--border); }
.quiz-result-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; margin-top: 1.5rem; }

.quiz-optional-note {
    font-size: 0.875rem;
    color: var(--text-muted);
    background: var(--surface);
    border: 1px dashed var(--border);
    border-radius: 8px;
    padding: 0.6rem 0.85rem;
    margin: 1rem 0 0.75rem;
}
.lesson-continue-form { margin-top: 1rem; }

/* ── Next lesson / resume / practice / search ── */
.lesson-next {
    margin-top: 2.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border);
}
.lesson-next-label { margin: 0; color: var(--text-muted); font-size: 0.9375rem; }
.lesson-next-label strong { color: var(--text-primary); }
.lesson-next .lesson-continue-form { margin: 0.75rem 0; }
.lesson-back-link { font-size: 0.875rem; color: var(--text-muted); }

.resume-card {
    display: grid;
    gap: 0.35rem;
    margin: 0 0 2rem;
    padding: 1.25rem 1.5rem;
    border: 1px solid var(--accent-terminal);
    border-radius: 10px;
    background: var(--surface);
    color: inherit;
    text-decoration: none;
    animation: fade-up var(--duration-base) var(--ease-out) both;
}
.resume-card:hover { color: inherit; box-shadow: 0 10px 30px -10px rgba(57, 211, 83, 0.25); }
.resume-kicker { font-size: 0.8125rem; color: var(--accent-terminal); font-weight: 600; }
.resume-title { font-size: 1.25rem; font-weight: 700; }
.resume-meta { font-size: 0.875rem; color: var(--text-muted); }
.resume-btn { justify-self: start; margin-top: 0.5rem; }

.practice-links {
    margin-top: 2.5rem;
    padding: 1.25rem 1.5rem;
    border: 1px dashed var(--border);
    border-radius: 10px;
    background: var(--surface);
    scroll-margin-top: 6rem;
}
.practice-links h2 { margin: 0 0 0.35rem; font-size: 1.125rem; }
.practice-list { list-style: none; margin: 1rem 0 0; padding: 0; display: grid; gap: 0.5rem; }
.practice-list a {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.25rem 0.75rem;
    padding: 0.7rem 0.9rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface-raised);
    color: inherit;
    text-decoration: none;
}
.practice-list a:hover { border-color: var(--accent-terminal); }
.practice-name { font-weight: 700; color: var(--accent-terminal); }
.practice-label { font-size: 0.875rem; color: var(--text-muted); }
.next-module { margin-top: 1.5rem; }

.search-page { max-width: 720px; margin: 0 auto; }
.search-form { display: flex; gap: 0.5rem; margin: 1rem 0; }
.search-form input {
    flex: 1;
    min-width: 0;
    padding: 0.6rem 0.8rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--form-surface);
    color: var(--form-text);
    font: inherit;
}
.search-meta { display: block; font-size: 0.8125rem; font-weight: 400; color: var(--text-muted); }
.visually-hidden {
    position: absolute;
    width: 1px; height: 1px;
    margin: -1px; padding: 0;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
    border: 0;
}

.lesson-page { max-width: 720px; margin: 0 auto; }
.lesson-body p { margin: 0 0 1rem; }
.lesson-body code { background: var(--surface); padding: 0.1rem 0.3rem; border-radius: 4px; }
.lesson-locked-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 2rem;
    text-align: center;
    animation: fade-up var(--duration-base) var(--ease-out) both;
}

/* ── Code blocks: macOS-terminal window chrome — the strongest, cheapest
   way to make "dark theme with monospace font" actually read as terminal
   themed rather than just dark-mode-default. ── */
pre.code-sample {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2rem 1rem 1rem;
    overflow-x: auto;
    position: relative;
}
pre.code-sample::before {
    content: '';
    position: absolute;
    top: 0.7rem; left: 1rem;
    width: 0.65rem; height: 0.65rem;
    border-radius: 50%;
    background: var(--danger);
    box-shadow: 1.1em 0 0 var(--accent-gold), 2.2em 0 0 var(--accent-terminal);
}

.quiz-form { margin-top: 2rem; }
.quiz-question {
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
    transition: border-color var(--duration-base) var(--ease-out);
}
.quiz-question:focus-within { border-color: var(--accent-terminal); }
.quiz-question legend { padding: 0 0.5rem; font-weight: 600; }
.quiz-option {
    display: block;
    padding: 0.5rem 0.6rem;
    margin: 0.15rem 0;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color var(--duration-fast) var(--ease-out);
}
.quiz-option:hover { background: rgba(57, 211, 83, 0.08); }
.lesson-completed-badge { color: var(--accent-terminal); font-weight: 600; animation: pop-in var(--duration-base) var(--ease-spring) both; }

.placement-test, .placement-result, .cheatsheet-page { max-width: 640px; margin: 0 auto; }
.track-picker select { padding: 0.6rem; border-radius: 6px; background: var(--form-surface); color: var(--form-text); border: 1px solid var(--border); margin: 1rem 0; }
.recommendation-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.5rem;
    text-align: center;
    margin-top: 1rem;
    animation: pop-in var(--duration-slow) var(--ease-spring) both;
}
.cheatsheet-summary, .cheatsheet-full { margin: 1rem 0; }

.problem-page, .submission-page { max-width: 720px; margin: 0 auto; }
.difficulty-badge { font-size: 0.75rem; padding: 0.15rem 0.5rem; border-radius: 4px; vertical-align: middle; }
.difficulty-easy { background: rgba(57,211,83,0.15); color: var(--accent-terminal); }
.difficulty-medium { background: rgba(245,166,35,0.15); color: var(--accent-gold); }
.difficulty-hard { background: rgba(248,81,73,0.15); color: var(--danger); }
.code-editor {
    width: 100%;
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
    transition: border-color var(--duration-base) var(--ease-out), box-shadow var(--duration-base) var(--ease-out);
}
.code-editor:focus { border-color: var(--accent-terminal) !important; box-shadow: 0 0 0 3px rgba(57, 211, 83, 0.15); }
.submission-status { font-size: 1.25rem; font-weight: 700; }
.status-passed { color: var(--accent-terminal); animation: pop-in var(--duration-slow) var(--ease-spring) both; }
.status-failed, .status-compile_error, .status-runtime_error { color: var(--danger); }
.test-result {
    padding: 0.5rem;
    border-radius: 6px;
    margin-bottom: 0.4rem;
    animation: fade-up var(--duration-base) var(--ease-out) both;
}
.test-pass { background: rgba(57,211,83,0.1); }
.test-fail { background: rgba(248,81,73,0.1); }
pre.stderr { color: var(--danger); }

/* Poll spinner for queued/running submissions — signals "working", not stalled. */
.submission-page[data-pending="1"] #poll-hint::before {
    content: '';
    display: inline-block;
    width: 0.75em; height: 0.75em;
    margin-right: 0.5em;
    border: 2px solid var(--border);
    border-top-color: var(--accent-terminal);
    border-radius: 50%;
    vertical-align: -0.1em;
    animation: spin 0.8s linear infinite;
}

.daily-challenge-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 1rem; margin-top: 1.5rem; }
.daily-challenge-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.25rem;
    transition: transform var(--duration-base) var(--ease-out), box-shadow var(--duration-base) var(--ease-out);
}
.daily-challenge-card:hover { transform: translateY(-3px); box-shadow: 0 10px 30px -10px rgba(245, 166, 35, 0.25); }
.leaderboard-page, .discussion-page { max-width: 640px; margin: 0 auto; }
.leaderboard-list { list-style: none; padding: 0; }
.leaderboard-list li {
    display: flex;
    gap: 1rem;
    padding: 0.6rem;
    border-bottom: 1px solid var(--border);
    transition: background-color var(--duration-fast) var(--ease-out);
    animation: fade-up var(--duration-base) var(--ease-out) both;
}
.leaderboard-list li:hover { background: rgba(255, 255, 255, 0.02); }
.leaderboard-list li.is-you { background: rgba(245, 166, 35, 0.08); border-radius: 6px; }
.leaderboard-list .rank { color: var(--text-muted); width: 3rem; }
.leaderboard-list .name { flex: 1; }
.leaderboard-list .xp { color: var(--accent-gold); font-weight: 600; }
.discussion-post { background: var(--surface); border-radius: 8px; padding: 0.75rem 1rem; margin-bottom: 0.75rem; animation: fade-up var(--duration-base) var(--ease-out) both; }
.discussion-post.is-reply { margin-left: 1.5rem; }
.post-author { font-weight: 600; margin: 0 0 0.25rem; color: var(--text-muted); font-size: 0.875rem; }
.post-body { margin: 0; }
.discussion-form textarea { width: 100%; background: var(--form-surface); color: var(--form-text); border: 1px solid var(--border); border-radius: 6px; padding: 0.6rem; }

.project-page { max-width: 720px; margin: 0 auto; }
.submission-status-card { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 1rem; margin: 1rem 0; }
.project-submit-form { display: flex; flex-direction: column; gap: 0.5rem; max-width: 480px; }
.project-submit-form input, .project-submit-form textarea {
    background: var(--form-surface); color: var(--form-text); border: 1px solid var(--border); border-radius: 6px; padding: 0.6rem;
}
.admin-queue .queue-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
    transition: border-color var(--duration-base) var(--ease-out);
}
.admin-queue .queue-item:hover { border-color: var(--accent-terminal); }

.static-page { max-width: 640px; margin: 0 auto; }
.static-page dt { font-weight: 700; margin-top: 1rem; }
.static-page dd { margin: 0.25rem 0 0; color: var(--text-muted); }
.contact-form { display: flex; flex-direction: column; gap: 0.5rem; max-width: 480px; }
.contact-form input, .contact-form textarea {
    background: var(--form-surface); color: var(--form-text); border: 1px solid var(--border); border-radius: 6px; padding: 0.6rem;
}
.hp-field { position: absolute; left: -9999px; top: -9999px; }

.landing-hero { text-align: center; padding: 3rem 0 2rem; animation: fade-up var(--duration-slow) var(--ease-out) both; }
.landing-hero h1 {
    background: linear-gradient(135deg, var(--text-primary) 40%, var(--accent-terminal));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.landing-hero .lede { color: var(--text-muted); max-width: 640px; margin: 1rem auto; }

/* Live-feeling proof point between the pitch and the price: the exact
   terminal chrome lessons use (pre.code-sample), typed out once on load,
   then the result appears — "try before you subscribe" without needing a
   real execution backend on the landing page. */
.landing-demo {
    max-width: 560px;
    margin: 2rem auto;
    animation: fade-up var(--duration-slow) var(--ease-out) both;
    animation-delay: 40ms;
}
.landing-demo-caption { color: var(--text-muted); font-size: 0.9375rem; text-align: center; margin: 0 0 0.75rem; }
.landing-demo-code { margin: 0; }
.landing-demo-cursor {
    display: inline-block;
    width: 0.5em;
    height: 1em;
    margin-left: 1px;
    vertical-align: text-bottom;
    background: var(--accent-terminal);
    animation: cursor-blink 1.1s steps(1) infinite;
}
.landing-demo-output {
    margin-top: 0.75rem;
    padding: 0.7rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9375rem;
    color: var(--accent-terminal);
    transition: opacity var(--duration-slow) var(--ease-out), transform var(--duration-slow) var(--ease-out);
}
.landing-demo-output-prompt { color: var(--text-muted); margin-right: 0.6em; }
.landing-demo-output.is-hidden { opacity: 0; transform: translateY(4px); }

.landing-cta {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    margin: 2rem 0;
    animation: fade-up var(--duration-slow) var(--ease-out) both;
    animation-delay: 80ms;
}
.cta-line { font-size: 1.25rem; font-weight: 700; color: var(--accent-gold); }
.cta-sub { color: var(--text-muted); }
.cta-body { max-width: 640px; margin: 1rem auto 1.5rem; color: var(--text-primary); }

.subscribe-box {
    background: var(--surface-raised);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    margin: 2rem 0;
    animation: fade-up var(--duration-slow) var(--ease-out) both;
    animation-delay: 140ms;
}
.subscribe-form { max-width: 360px; margin: 1rem auto 0; display: flex; flex-direction: column; gap: 0.5rem; }
.subscribe-form input,
.otp-form input {
    background: var(--form-surface);
    color: var(--form-text);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.6rem;
    min-height: 44px;
    font-size: 1.1rem;
    text-align: center;
}
.subscribe-form label, .otp-form label { text-align: left; font-size: 0.875rem; color: var(--text-muted); }
.hint { font-size: 0.8125rem; color: var(--text-muted); margin: 0.25rem 0; }
.form-error { color: var(--danger); font-weight: 600; }

.legal-warning {
    background: var(--surface);
    color: var(--text-muted);
    font-size: 0.8125rem;
    text-align: center;
    padding: 0.75rem 1rem;
    border-top: 1px solid var(--border);
}

.otp-verify { text-align: center; }
.otp-form { max-width: 260px; margin: 1rem auto; display: flex; flex-direction: column; gap: 0.5rem; }
.otp-resend-form { margin-top: 1rem; }

.notice {
    max-width: 640px;
    margin: 1rem auto 0;
    padding: 0.75rem 1rem;
    border-radius: 6px;
    text-align: center;
    animation: notice-in var(--duration-base) var(--ease-out) both;
}
.notice-success { background: rgba(57,211,83,0.12); color: var(--accent-terminal); }
.notice-error { background: rgba(248,81,73,0.12); color: var(--danger); }
.notice-info { background: rgba(88,166,255,0.12); color: var(--info); }

.dashboard-page { max-width: 960px; margin: 0 auto; }
.dashboard-stats { display: flex; gap: 1rem; flex-wrap: wrap; margin-bottom: 2rem; }
.stat-tile {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.25rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    flex: 1;
    min-width: 140px;
    transition: transform var(--duration-base) var(--ease-out), box-shadow var(--duration-base) var(--ease-out);
    animation: pop-in var(--duration-slow) var(--ease-spring) both;
}
.stat-tile:nth-child(2) { animation-delay: 60ms; }
.stat-tile:nth-child(3) { animation-delay: 120ms; }
.stat-tile:hover { transform: translateY(-2px); box-shadow: 0 10px 24px -12px rgba(245, 166, 35, 0.3); }
.stat-icon { font-size: 1.5rem; }
.stat-value { font-size: 1.75rem; font-weight: 700; color: var(--accent-gold); font-variant-numeric: tabular-nums; }
.stat-label { color: var(--text-muted); font-size: 0.8125rem; }

.daily-challenge-strip { margin-bottom: 2rem; }
.daily-challenge-card { display: flex; flex-direction: column; gap: 0.25rem; text-decoration: none; color: var(--text-primary); }

.dashboard-trees { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; }
.dashboard-tree-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1.25rem;
    transition: border-color var(--duration-base) var(--ease-out);
    animation: fade-up var(--duration-slow) var(--ease-out) both;
}
.dashboard-tree-card:hover { border-color: var(--accent-terminal); }

/* ── Keyframes ── */
@keyframes cursor-blink { 0%, 45% { opacity: 1; } 50%, 95% { opacity: 0; } 100% { opacity: 1; } }
@keyframes fade-up { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
@keyframes node-in { from { opacity: 0; transform: translateX(-8px); } to { opacity: 1; transform: translateX(0); } }
@keyframes pop-in { from { opacity: 0; transform: scale(0.92); } to { opacity: 1; transform: scale(1); } }
@keyframes notice-in { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: translateY(0); } }
@keyframes gold-pulse {
    0%, 100% { text-shadow: 0 0 0 rgba(245, 166, 35, 0); }
    50% { text-shadow: 0 0 10px rgba(245, 166, 35, 0.85); }
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Hybrid projects & track-lock UI ── */
.language-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0.5rem 0; }
.language-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
    background: var(--surface-raised);
    border: 1px solid var(--border);
    color: var(--text-muted);
}
.language-chip.is-complete { color: var(--accent-terminal); border-color: var(--accent-terminal); }
.hybrid-badge {
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
    background: rgba(245, 166, 35, 0.15);
    color: var(--accent-gold);
    font-weight: 600;
}
.readiness-badge { font-size: 0.8125rem; margin: 0.5rem 0 0; font-weight: 600; }
.readiness-badge.is-ready { color: var(--accent-terminal); }
.readiness-badge.is-locked { color: var(--text-muted); font-weight: 400; }
.readiness-badge.is-pending { color: var(--accent-gold); }
.readiness-badge.is-approved { color: var(--accent-terminal); }
.readiness-badge.is-changes { color: var(--danger); }
.project-card.is-ready:hover, .project-card.is-approved:hover { border-color: var(--accent-terminal); }
.project-card.is-locked { opacity: 0.85; }
.project-card.is-changes:hover { border-color: var(--danger); }

.track-card.is-track-locked {
    opacity: 0.6;
    cursor: not-allowed;
}
.track-card.is-track-locked:hover { transform: none; box-shadow: none; border-color: var(--border); }
.track-lock-note { font-size: 0.75rem; color: var(--text-muted); margin: 0.35rem 0 0; }

/* Reduced motion: keep opacity-only cross-fades, drop everything spatial/spring. */
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    .brand::after { animation: none; opacity: 1; }
    .site-main, .status-badge, .track-card, .skill-node, .lesson-locked-card,
    .lesson-completed-badge, .recommendation-card, .status-passed, .test-result,
    .leaderboard-list li, .discussion-post, .landing-hero, .landing-cta,
    .landing-demo, .subscribe-box, .notice, .stat-tile, .dashboard-tree-card,
    .quiz-result-banner, .price-amount {
        animation: none !important;
    }
    .btn, .track-card, .daily-challenge-card, .stat-tile, a, input, select, textarea {
        transition-duration: 1ms !important;
    }
    .btn:hover, .track-card:hover, .daily-challenge-card:hover, .stat-tile:hover { transform: none !important; }
    .skill-icon-partial, .landing-demo-cursor { animation: none; opacity: 1; }
    .submission-page[data-pending="1"] #poll-hint::before { animation-duration: 1.4s; }
}

/* Reduced transparency: the nav is the app's one translucent material —
   go solid instead of blurred when the user has asked for less transparency. */
@media (prefers-reduced-transparency: reduce) {
    .site-nav {
        background: var(--bg-primary);
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
    }
}

/* Higher contrast: near-solid surfaces with a defined border, instead of the
   subtle hairlines/tints used by default. */
@media (prefers-contrast: more) {
    :root { --border: #6E7681; --text-muted: #B1BAC4; }
    .site-nav { background: var(--bg-primary); backdrop-filter: none; -webkit-backdrop-filter: none; }
    .btn { border: 1px solid currentColor; }
    .skill-node-link:focus-visible,
    a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
        outline-width: 3px;
    }
}