:root {
    color-scheme: dark;
    --bg: #07100f;
    --surface: rgba(17, 36, 32, 0.72);
    --surface-strong: #132b26;
    --line: rgba(187, 232, 213, 0.16);
    --text: #f3f7f5;
    --muted: #aec1ba;
    --accent: #79e2b7;
    --accent-deep: #164d3d;
    --max: 72rem;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { min-height: 100%; background: var(--bg); }
body { min-height: 100vh; margin: 0; color: var(--text); background: radial-gradient(circle at 80% 15%, rgba(42, 132, 101, .22), transparent 34rem), linear-gradient(145deg, #07100f 0%, #0a1916 55%, #07100f 100%); line-height: 1.6; }
a { color: inherit; text-decoration: none; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; border-radius: .25rem; }
.shell { width: min(calc(100% - 2rem), var(--max)); margin-inline: auto; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 10; padding: .7rem 1rem; color: #052118; background: var(--accent); font-weight: 800; }
.skip-link:focus { top: 1rem; }
.site-header { border-bottom: 1px solid var(--line); background: rgba(7, 16, 15, .72); backdrop-filter: blur(18px); }
.nav-shell { min-height: 5rem; display: flex; align-items: center; justify-content: space-between; gap: 2rem; }
.brand { display: inline-flex; align-items: center; gap: .75rem; font-weight: 850; letter-spacing: .08em; }
.brand-mark { display: grid; place-items: center; width: 2.25rem; height: 2.25rem; border-radius: .75rem; color: #062018; background: var(--accent); box-shadow: 0 0 2rem rgba(121, 226, 183, .25); }
nav { display: flex; align-items: center; gap: clamp(.75rem, 3vw, 2rem); color: var(--muted); }
nav a:hover { color: var(--text); }
.nav-user { color: var(--accent); font-weight: 700; }
.logout-form { margin: 0; }
.nav-button { color: var(--text); background: transparent; font: inherit; cursor: pointer; }
.nav-cta { padding: .55rem .9rem; border: 1px solid var(--line); border-radius: 999px; }
.hero { min-height: 38rem; padding-block: clamp(4rem, 10vw, 8rem); display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: clamp(3rem, 8vw, 7rem); }
.eyebrow { color: var(--accent); font-size: .78rem; font-weight: 800; letter-spacing: .15em; text-transform: uppercase; }
h1 { max-width: 14ch; margin: .5rem 0 1.25rem; font-size: clamp(2.6rem, 7vw, 5.5rem); line-height: .98; letter-spacing: -.055em; }
.hero-intro, .message-page > p:not(.eyebrow, .status-code) { max-width: 39rem; color: var(--muted); font-size: clamp(1.05rem, 2vw, 1.25rem); }
.hero-actions { display: flex; flex-wrap: wrap; gap: .85rem; margin-top: 2rem; }
.welcome-status { display: inline-flex; margin: 0 0 1rem; padding: .45rem .8rem; border: 1px solid var(--line); border-radius: 999px; color: var(--accent); background: rgba(121, 226, 183, .06); }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 3.25rem; padding: .75rem 1.25rem; border: 1px solid transparent; border-radius: .85rem; font-weight: 750; transition: transform .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { color: #062018; background: var(--accent); }
.button-secondary { border-color: var(--line); background: rgba(255, 255, 255, .035); }
.learning-card, .glass-panel, .phase-note { border: 1px solid var(--line); background: linear-gradient(150deg, rgba(30, 65, 57, .72), rgba(12, 28, 25, .78)); box-shadow: 0 2rem 5rem rgba(0, 0, 0, .3); backdrop-filter: blur(16px); }
.learning-card { position: relative; padding: 1.5rem; border-radius: 1.75rem; transform: rotate(2deg); }
.learning-card::before { content: ""; position: absolute; inset: -1rem 1rem 1rem -1rem; z-index: -1; border: 1px solid var(--line); border-radius: 1.75rem; background: rgba(121, 226, 183, .045); transform: rotate(-5deg); }
.card-topline, .answer-row { display: flex; justify-content: space-between; gap: 1rem; color: var(--muted); font-size: .78rem; }
.word-pair { min-height: 16rem; display: grid; place-content: center; gap: .4rem; text-align: center; font-size: 1.2rem; }
.word-pair strong { color: var(--accent); font-size: clamp(2rem, 5vw, 3.4rem); letter-spacing: -.04em; }
.progress-track { height: .35rem; margin: 0 0 1.25rem; overflow: hidden; border-radius: 1rem; background: rgba(255, 255, 255, .08); }
.progress-track span { display: block; width: 58%; height: 100%; background: var(--accent); }
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; padding-block: 1rem 5rem; }
.glass-panel { padding: 2rem; border-radius: 1.25rem; box-shadow: none; }
.feature-number { color: var(--accent); font: 700 .78rem ui-monospace, monospace; }
.glass-panel h2 { margin: 2.5rem 0 .5rem; font-size: 1.25rem; }
.glass-panel p { margin: 0; color: var(--muted); }
.spotlight { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(2rem, 7vw, 7rem); align-items: start; padding-block: clamp(2.5rem, 6vw, 5rem); border-top: 1px solid var(--line); }
.spotlight h2 { max-width: 12ch; margin: .4rem 0; font-size: clamp(2rem, 4vw, 3.3rem); line-height: 1.05; letter-spacing: -.04em; }
.spotlight > p { max-width: 43rem; margin: .4rem 0; color: var(--muted); font-size: 1.1rem; }
.phase-note { margin-bottom: 5rem; padding: 1rem 1.25rem; border-radius: 1rem; color: var(--muted); box-shadow: none; }
.phase-note span { margin-right: .65rem; color: var(--accent); }
.message-page { min-height: 67vh; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; padding-block: 5rem; }
.message-page h1 { font-size: clamp(2.5rem, 7vw, 5rem); }
.message-page .button { margin-top: 1.5rem; }
.auth-page { min-height: 70vh; display: grid; place-items: center; padding-block: clamp(3rem, 8vw, 7rem); }
.auth-card { width: min(100%, 34rem); padding: clamp(1.5rem, 5vw, 3rem); border: 1px solid var(--line); border-radius: 1.5rem; background: linear-gradient(150deg, rgba(30, 65, 57, .78), rgba(12, 28, 25, .9)); box-shadow: 0 2rem 5rem rgba(0, 0, 0, .3); }
.auth-card h1 { max-width: none; font-size: clamp(2.2rem, 7vw, 3.5rem); }
.auth-card > p:not(.eyebrow) { color: var(--muted); }
.auth-card form:not(.logout-form) { display: grid; gap: .65rem; margin-top: 2rem; }
.auth-card label { margin-top: .65rem; font-weight: 700; }
.auth-card input { width: 100%; min-height: 3.25rem; padding: .75rem .9rem; border: 1px solid var(--line); border-radius: .75rem; color: var(--text); background: rgba(2, 12, 10, .55); font: inherit; }
.auth-card input:focus { border-color: var(--accent); outline: 2px solid rgba(121, 226, 183, .25); outline-offset: 2px; }
.auth-card small { color: var(--muted); }
.auth-card .field-error { color: #ffaaa4; }
.auth-card .button { margin-top: 1rem; cursor: pointer; font: inherit; }
.auth-alternative, .auth-links { margin-top: 1.5rem; color: var(--muted); }
.auth-alternative a, .auth-links a { color: var(--accent); text-decoration: underline; text-underline-offset: .2em; }
.auth-links { display: flex; justify-content: space-between; gap: 1rem; }
.auth-card-centered { text-align: center; }
.auth-card-centered .button { margin-top: 1.25rem; }
.auth-icon { display: grid; place-items: center; width: 3.5rem; height: 3.5rem; margin: 0 auto 1.5rem; border-radius: 50%; color: #062018; background: var(--accent); font-size: 1.7rem; font-weight: 800; }
.auth-icon-error { color: var(--text); background: #723d3a; }
.status-code { margin: 0; color: var(--accent); font: 750 1rem ui-monospace, monospace; }
.request-reference { padding: .5rem .75rem; border: 1px solid var(--line); border-radius: .5rem; font-family: ui-monospace, monospace; font-size: .85rem; }
.debug-details { max-width: 100%; margin: 1rem 0; }
.debug-details pre { max-width: min(80vw, 65rem); overflow: auto; padding: 1rem; border: 1px solid var(--line); border-radius: .75rem; }
.site-footer { border-top: 1px solid var(--line); color: var(--muted); }
.footer-shell { min-height: 7rem; display: flex; align-items: center; justify-content: space-between; gap: 2rem; }
.footer-shell > div, .footer-links { display: flex; flex-wrap: wrap; gap: .75rem 1.5rem; }
.footer-shell strong { color: var(--text); }
.footer-links a:hover { color: var(--accent); }

@media (max-width: 48rem) {
    .nav-shell { min-height: auto; padding-block: 1rem; align-items: flex-start; }
    nav { align-items: flex-end; flex-direction: column; gap: .35rem; }
    .nav-cta { padding: .2rem .65rem; }
    .hero { grid-template-columns: 1fr; min-height: auto; }
    .learning-card { max-width: 31rem; }
    .features { grid-template-columns: 1fr; }
    .spotlight { grid-template-columns: 1fr; gap: 1rem; }
    .footer-shell { padding-block: 2rem; align-items: flex-start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}