:root {
    --bg: #0b1020;
    --panel: #11182d;
    --panel-2: #171f37;
    --line: rgba(255,255,255,.08);
    --text: #eef2ff;
    --muted: #a8b3cf;
    --primary: #62b0ff;
    --primary-2: #8b5cf6;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --shadow: 0 18px 40px rgba(0,0,0,.25);
    --radius: 22px;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: radial-gradient(circle at top, #17213b, #0b1020 55%); color: var(--text); font-family: Tahoma, Arial, sans-serif; }
a { color: inherit; text-decoration: none; }
body { min-height: 100vh; }
.app-shell { min-height: 100vh; display: flex; flex-direction: column; }
.topbar { position: sticky; top: 0; z-index: 30; backdrop-filter: blur(16px); background: rgba(11,16,32,.8); border-bottom: 1px solid var(--line); padding: 14px 22px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand-wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; }
.brand { display: inline-flex; align-items: center; gap: 14px; }
.brand strong { display: block; font-size: 1rem; }
.brand small { display: block; color: var(--muted); margin-top: 4px; }
.brand-mark { width: 46px; height: 46px; border-radius: 16px; display: grid; place-items: center; font-weight: 800; background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: white; box-shadow: var(--shadow); }
.main-nav { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.main-nav a { padding: 10px 14px; border-radius: 14px; color: #dbeafe; }
.main-nav a.active, .main-nav a:hover { background: rgba(255,255,255,.08); }
.nav-toggle { display: none; background: rgba(255,255,255,.08); color: var(--text); border: 0; border-radius: 12px; padding: 10px 12px; }
.page-wrap { width: min(1240px, calc(100% - 28px)); margin: 26px auto; display: block; }
.hero { display: grid; grid-template-columns: 1.2fr .8fr; gap: 24px; align-items: stretch; }
.card, .hero-card, .panel, .stat, .form-card, .lesson-block { background: linear-gradient(180deg, rgba(255,255,255,.04), rgba(255,255,255,.02)); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.hero-card { padding: 30px; }
.hero h1 { margin: 0 0 12px; font-size: clamp(1.9rem, 4vw, 3.1rem); line-height: 1.15; }
.hero p { color: var(--muted); line-height: 1.9; }
.hero-badges, .stack { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }
.badge, .pill { display: inline-flex; align-items: center; gap: 8px; padding: 10px 14px; border-radius: 999px; background: rgba(255,255,255,.07); border: 1px solid rgba(255,255,255,.06); color: #eef4ff; font-size: .92rem; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 13px 18px; border-radius: 16px; background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: white; border: 0; cursor: pointer; font-weight: 700; }
.button.secondary { background: rgba(255,255,255,.08); }
.button.ghost { background: transparent; border: 1px solid rgba(255,255,255,.1); }
.button-sm { padding: 9px 12px; border-radius: 12px; }
.grid-2, .grid-3, .grid-4 { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.stat { padding: 22px; }
.stat small, .muted { color: var(--muted); }
.stat strong { font-size: 2rem; display: block; margin-top: 12px; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin: 30px 0 16px; }
.section-head h1, .section-head h2, .section-head h3 { margin: 0; }
.panel { padding: 24px; }
.lesson-card { padding: 20px; display: flex; flex-direction: column; gap: 14px; }
.lesson-card h3, .lesson-block h3 { margin: 0; }
.level-chip { padding: 7px 10px; border-radius: 999px; font-weight: 700; font-size: .85rem; display: inline-block; }
.level-a1 { background: rgba(34,197,94,.18); color: #b8ffd1; }
.level-a2 { background: rgba(6,182,212,.18); color: #b9f8ff; }
.level-b1 { background: rgba(245,158,11,.18); color: #ffe1aa; }
.level-b2 { background: rgba(139,92,246,.18); color: #e3d6ff; }
.level-c1 { background: rgba(239,68,68,.18); color: #ffc6c6; }
.badge-success { background: rgba(34,197,94,.18); color: #b8ffd1; }
.badge-warning { background: rgba(245,158,11,.18); color: #ffe1aa; }
.badge-muted { background: rgba(148,163,184,.16); color: #d4deef; }
.flash { padding: 14px 18px; border-radius: 16px; margin-bottom: 18px; }
.flash-success { background: rgba(34,197,94,.15); border: 1px solid rgba(34,197,94,.28); }
.flash-error { background: rgba(239,68,68,.15); border: 1px solid rgba(239,68,68,.28); }
.flash-info { background: rgba(98,176,255,.12); border: 1px solid rgba(98,176,255,.24); }
.form-card { padding: 26px; max-width: 760px; margin: 0 auto; }
label { display: block; margin-bottom: 8px; font-weight: 700; }
input, textarea, select { width: 100%; background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.1); color: white; border-radius: 16px; padding: 14px 14px; font-size: 1rem; }
textarea { min-height: 150px; resize: vertical; }
input::placeholder, textarea::placeholder { color: #91a0bd; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 16px; }
.form-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 18px; }
.lesson-hero { padding: 28px; display: grid; grid-template-columns: 1.2fr .8fr; gap: 20px; }
.lesson-meta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.lesson-block { padding: 22px; margin-bottom: 18px; }
.list-clean { padding: 0 18px 0 0; margin: 0; line-height: 2; }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px 10px; border-bottom: 1px solid var(--line); text-align: start; vertical-align: top; }
.dialogue { display: grid; gap: 12px; }
.dialogue-line { padding: 14px; border-radius: 18px; border: 1px solid var(--line); background: rgba(255,255,255,.04); }
.dialogue-line strong { display: inline-block; min-width: 42px; color: #9bd0ff; }
.translation { color: var(--muted); margin-top: 6px; font-size: .95rem; }
.ltr { direction: ltr; text-align: left; }
.score-box { padding: 16px; border-radius: 18px; background: rgba(255,255,255,.05); border: 1px dashed rgba(255,255,255,.12); }
.quiz-option { display: grid; grid-template-columns: 24px 1fr; gap: 12px; align-items: start; margin-bottom: 10px; padding: 12px; border: 1px solid var(--line); border-radius: 16px; background: rgba(255,255,255,.04); }
.progress-bar { width: 100%; height: 10px; border-radius: 999px; background: rgba(255,255,255,.08); overflow: hidden; }
.progress-bar > span { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), var(--primary-2)); }
.site-footer { margin-top: auto; padding: 24px 22px 36px; display: flex; align-items: center; justify-content: space-between; gap: 14px; color: var(--muted); border-top: 1px solid var(--line); }
.footer-meta { display: flex; gap: 12px; flex-wrap: wrap; }
.kpis { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
.helper { color: var(--muted); font-size: .92rem; margin-top: 8px; }
.notice { padding: 14px 16px; border-radius: 16px; background: rgba(98,176,255,.10); border: 1px solid rgba(98,176,255,.22); }
.result-panel { margin-top: 12px; }
.empty-state { padding: 28px; text-align: center; color: var(--muted); border: 1px dashed var(--line); border-radius: 22px; }
@media (max-width: 980px) {
    .hero, .lesson-hero, .grid-4, .grid-3, .grid-2, .kpis { grid-template-columns: 1fr; }
    .topbar { align-items: start; flex-direction: column; }
    .main-nav { display: none; width: 100%; }
    body.nav-open .main-nav { display: flex; flex-direction: column; align-items: stretch; }
    .nav-toggle { display: inline-flex; }
    .brand-wrap { width: 100%; }
    .site-footer { flex-direction: column; align-items: start; }
    .form-grid { grid-template-columns: 1fr; }
}