/* === DESIGN TOKENS === */
:root {
  --primary: #01696f;
  --primary-hover: #0c4e54;
  --text: #28251d;
  --text-muted: #7a7974;
  --bg: #f7f6f2;
  --surface: #f9f8f5;
  --surface-2: #fbfbf9;
  --border: #d4d1ca;
  --error: #a12c7b;
  --success: #437a22;
  --warning: #964219;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --shadow: 0 4px 12px rgba(0,0,0,0.08);
  --font: 'Nunito', 'Arial', sans-serif;
  --transition: 180ms cubic-bezier(0.16,1,0.3,1);

  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font); font-size: var(--text-base); color: var(--text); background: var(--bg); min-height: 100dvh; display: flex; flex-direction: column; }
img { display: block; max-width: 100%; }
input, button, select, textarea { font: inherit; color: inherit; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button { cursor: pointer; }

/* === LAYOUT === */
.container { max-width: 960px; margin-inline: auto; padding-inline: 1rem; }
.main-content { flex: 1; padding-block: 2rem; }

/* === HEADER === */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.header-inner { display: flex; align-items: center; gap: 1rem; height: 60px; }
.logo { display: flex; align-items: center; gap: .5rem; font-weight: 700; font-size: var(--text-lg); color: var(--text); text-decoration: none; }
.main-nav { display: flex; gap: 1.5rem; margin-left: 2rem; }
.main-nav a { font-size: var(--text-sm); color: var(--text-muted); font-weight: 600; }
.main-nav a:hover { color: var(--primary); }
.header-auth { margin-left: auto; display: flex; gap: .5rem; }
.nav-burger { display: none; flex-direction: column; gap: 4px; padding: .5rem; background: none; border: none; }
.nav-burger span { display: block; width: 22px; height: 2px; background: var(--text); border-radius: 2px; }
.mobile-nav { display: none; flex-direction: column; gap: .5rem; background: var(--surface); border-bottom: 1px solid var(--border); padding: 1rem; }
.mobile-nav.open { display: flex; }

/* === BUTTONS === */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .4rem; padding: .6rem 1.25rem; border-radius: var(--radius); font-size: var(--text-sm); font-weight: 600; border: 2px solid transparent; transition: all var(--transition); text-decoration: none; }
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); border-color: var(--primary-hover); }
.btn-secondary { background: transparent; color: var(--primary); border-color: var(--primary); }
.btn-secondary:hover { background: var(--primary); color: #fff; }
.btn-ghost { background: transparent; color: var(--text-muted); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--text-muted); color: var(--text); }
.btn-large { padding: .85rem 2rem; font-size: var(--text-base); }
.btn-full { width: 100%; }
.btn-sm { padding: .35rem .75rem; font-size: var(--text-sm); }

/* === ALERTS === */
.alert { padding: .75rem 1rem; border-radius: var(--radius); margin-bottom: 1rem; font-size: var(--text-sm); }
.alert-error, .alert-danger { background: #fce4f0; color: #7d1e5e; border: 1px solid #d9a0c5; }
.alert-success { background: #d4dfcc; color: #1e3f0a; border: 1px solid #b8ceab; }
.alert-info { background: #cedcd8; color: #0f3638; border: 1px solid #9fc3bf; }

/* === FORMS === */
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; font-weight: 600; margin-bottom: .4rem; font-size: var(--text-sm); }
.form-input, input[type="text"], input[type="number"], input[type="password"], select { width: 100%; padding: .65rem .9rem; border: 1.5px solid var(--border); border-radius: var(--radius); font-size: var(--text-base); background: var(--surface-2); transition: border-color var(--transition); }
.form-input:focus, input:focus, select:focus { outline: none; border-color: var(--primary); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.field-error { color: var(--error); font-size: .875rem; margin-top: .25rem; }
.checkbox-group { display: flex; gap: 1rem; flex-wrap: wrap; }
.checkbox-group label { display: flex; align-items: center; gap: .4rem; font-size: var(--text-lg); font-weight: 700; cursor: pointer; padding: .5rem 1rem; border: 2px solid var(--border); border-radius: var(--radius); }
.checkbox-group label:has(input:checked) { border-color: var(--primary); background: #cedcd8; }
.range-input { width: 100%; accent-color: var(--primary); }
.range-labels { display: flex; justify-content: space-between; font-size: .8rem; color: var(--text-muted); }

/* === TABS === */
.tab-bar { display: flex; gap: .5rem; margin-bottom: 1.5rem; border-bottom: 2px solid var(--border); padding-bottom: .5rem; flex-wrap: wrap; }
.tab-btn { padding: .5rem 1.25rem; border-radius: var(--radius); border: 2px solid var(--border); background: var(--surface); font-weight: 600; font-size: var(--text-sm); color: var(--text-muted); }
.tab-btn:hover, .tab-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* === HOME === */
.hero { text-align: center; padding: 3rem 0; }
.hero-title { font-size: var(--text-xl); font-weight: 800; color: var(--text); margin-bottom: 1rem; }
.hero-sub { font-size: var(--text-lg); color: var(--text-muted); max-width: 560px; margin: 0 auto 2rem; }
.hero-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1.5rem; margin-top: 3rem; }
.feature-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.5rem; }
.feature-icon { font-size: 2rem; margin-bottom: .75rem; }
.feature-card h3 { font-size: var(--text-base); font-weight: 700; margin-bottom: .5rem; }
.feature-card p { color: var(--text-muted); font-size: var(--text-sm); }

/* === AUTH === */
.auth-card { max-width: 420px; margin: 2rem auto; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 2rem; }
.auth-form { margin-top: 1.5rem; }
.auth-link { text-align: center; margin-top: 1rem; font-size: var(--text-sm); color: var(--text-muted); }
.page-title { font-size: var(--text-xl); font-weight: 800; margin-bottom: 1.5rem; }

/* === TRAINER === */
.trainer-wrap { max-width: 600px; margin: 0 auto; }
.trainer-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1rem; flex-wrap: wrap; }
.trainer-progress { font-weight: 600; color: var(--text-muted); }
.timer-session { font-size: var(--text-base); font-weight: 700; color: var(--primary); margin-left: auto; }
.progress-bar { height: 6px; background: var(--border); border-radius: 3px; margin-bottom: 2rem; }
.progress-fill { height: 100%; background: var(--primary); border-radius: 3px; transition: width .3s ease; }
.example-card { background: var(--surface); border: 2px solid var(--border); border-radius: var(--radius-lg); padding: 2.5rem; text-align: center; margin-bottom: 1.5rem; box-shadow: var(--shadow); }
.example-expr { font-size: clamp(2rem, 6vw, 3.5rem); font-weight: 800; color: var(--text); }
.example-timer { font-size: var(--text-sm); color: var(--text-muted); margin-top: .75rem; }
.answer-form { display: flex; gap: .75rem; }
.answer-input { flex: 1; padding: .85rem 1rem; font-size: var(--text-xl); font-weight: 700; border: 2.5px solid var(--border); border-radius: var(--radius); text-align: center; }
.answer-input:focus { border-color: var(--primary); outline: none; }

/* === RESULT === */
.result-summary { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 1rem; margin-bottom: 2rem; }
.result-stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; text-align: center; }
.stat-val { display: block; font-size: var(--text-xl); font-weight: 800; color: var(--primary); }
.stat-lbl { font-size: var(--text-sm); color: var(--text-muted); }
.errors-table { width: 100%; border-collapse: collapse; margin-bottom: 2rem; }
.errors-table th, .errors-table td { padding: .65rem .9rem; border-bottom: 1px solid var(--border); text-align: left; font-size: var(--text-sm); }
.errors-table th { font-weight: 700; background: var(--surface); }
.wrong { color: var(--error); font-weight: 700; }
.correct { color: var(--success); font-weight: 700; }
.expr-cell { font-size: var(--text-base); font-weight: 600; font-family: monospace; }
.success-banner { background: #d4dfcc; color: #1e3f0a; border-radius: var(--radius); padding: 1.5rem; text-align: center; font-size: var(--text-lg); font-weight: 700; margin-bottom: 2rem; }
.result-actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2rem; }
.section-title { font-size: var(--text-lg); font-weight: 700; margin-bottom: 1rem; margin-top: 1.5rem; }
.recs-list { list-style: none; }
.recs-list li { padding: .75rem 1rem; border-left: 3px solid var(--primary); background: var(--surface); margin-bottom: .75rem; border-radius: 0 var(--radius) var(--radius) 0; font-size: var(--text-sm); }

/* === SETTINGS FORM === */
.settings-form { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 2rem; }
.mt-4 { margin-top: 1.5rem; }
.hint { color: var(--text-muted); font-size: var(--text-sm); margin-bottom: 1rem; }
.slot-label { font-weight: 700; min-width: 1.5rem; }
.slot-input { width: 80px !important; }
.level-cards { display: flex; gap: .75rem; margin-bottom: 1rem; }
.level-card { display: flex; align-items: center; justify-content: center; width: 52px; height: 52px; border: 2px solid var(--border); border-radius: var(--radius); cursor: pointer; font-weight: 800; font-size: var(--text-lg); }
.level-card:has(input:checked) { border-color: var(--primary); background: #cedcd8; color: var(--primary); }
.level-card input { display: none; }
.level-desc { font-size: var(--text-sm); color: var(--text-muted); }

/* === CABINET === */
.cabinet-layout { display: grid; grid-template-columns: 200px 1fr; gap: 2rem; align-items: start; }
.cabinet-nav { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1rem; display: flex; flex-direction: column; gap: .5rem; }
.cabinet-nav a { padding: .6rem .9rem; border-radius: var(--radius); font-weight: 600; font-size: var(--text-sm); color: var(--text-muted); }
.cabinet-nav a:hover, .cabinet-nav a.active { background: #cedcd8; color: var(--primary); text-decoration: none; }
.cabinet-main { min-width: 0; }
.kpi-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 1rem; margin-bottom: 2rem; }
.kpi-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; text-align: center; }
.kpi-val { display: block; font-size: var(--text-xl); font-weight: 800; color: var(--primary); }
.kpi-lbl { font-size: var(--text-sm); color: var(--text-muted); }
.charts-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin-bottom: 2rem; }
.chart-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.25rem; }
.chart-card h3 { font-size: var(--text-sm); font-weight: 700; margin-bottom: .75rem; color: var(--text-muted); }
.table-wrap { overflow-x: auto; }
.data-table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); }
.data-table th, .data-table td { padding: .65rem .75rem; border-bottom: 1px solid var(--border); text-align: left; }
.data-table th { font-weight: 700; background: var(--surface); }
.data-table tr:hover td { background: var(--surface); }
.empty-cell { text-align: center; color: var(--text-muted); padding: 2rem !important; }
.badge { padding: .25rem .6rem; border-radius: var(--radius); font-size: .75rem; font-weight: 700; }
.badge-ok { background: #d4dfcc; color: #1e3f0a; }
.badge-warn { background: #e7d7c4; color: #964219; }
.page-desc { color: var(--text-muted); margin-bottom: 1.5rem; }
.empty-state { text-align: center; padding: 3rem 1rem; color: var(--text-muted); }
.recs-list-large .rec-item { display: flex; gap: .75rem; align-items: flex-start; padding: 1rem 1.25rem; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--border); margin-bottom: 1rem; font-size: var(--text-base); }
.rec-icon { font-size: 1.4rem; flex-shrink: 0; }

/* === FOOTER === */
.site-footer { border-top: 1px solid var(--border); padding: 1.25rem 0; text-align: center; font-size: var(--text-sm); color: var(--text-muted); background: var(--surface); }

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .main-nav, .header-auth { display: none; }
  .nav-burger { display: flex; }
  .form-row { grid-template-columns: 1fr; }
  .cabinet-layout { grid-template-columns: 1fr; }
  .cabinet-nav { flex-direction: row; flex-wrap: wrap; }
  .charts-grid { grid-template-columns: 1fr; }
  .answer-form { flex-direction: column; }
  .hero-actions { flex-direction: column; align-items: center; }
  .result-summary { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
  .example-expr { font-size: 2.2rem; }
  .example-card { padding: 1.5rem 1rem; }
  .trainer-header { gap: .5rem; }
}