/* ============================================================
   Learn Platform — Public Site Styles
   ============================================================ */

:root {
  --bg: #fafbfc;
  --bg-elevated: #ffffff;
  --ink: #0f1117;
  --ink-soft: #4b5563;
  --ink-dim: #6b7280;
  --ink-faint: #9ca3af;
  --border: #e5e7eb;
  --border-soft: #f3f4f6;
  --accent: #2754ff;
  --accent-hover: #1c44e0;
  --accent-soft: #eef2ff;
  --success: #059669;
  --success-soft: #d1fae5;
  --warning: #d97706;
  --danger: #dc2626;
  --shadow-sm: 0 1px 2px rgba(15,17,23,0.04), 0 1px 1px rgba(15,17,23,0.03);
  --shadow-md: 0 4px 12px rgba(15,17,23,0.06), 0 2px 4px rgba(15,17,23,0.04);
  --shadow-lg: 0 16px 36px rgba(15,17,23,0.08), 0 4px 8px rgba(15,17,23,0.04);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --font-display: 'Fraunces', 'Georgia', serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', Roboto, sans-serif;
  --container: 1200px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; scroll-behavior: smooth; }
body { margin: 0; font-family: var(--font-body); background: var(--bg); color: var(--ink); font-size: 15px; line-height: 1.6; }
a { color: var(--accent); text-decoration: none; transition: color 0.15s; }
a:hover { color: var(--accent-hover); text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
button, input, select, textarea { font-family: inherit; font-size: inherit; }

h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 600; letter-spacing: -0.02em; line-height: 1.2; margin: 0 0 0.5em; }
h1 { font-size: clamp(28px, 5vw, 44px); }
h2 { font-size: clamp(22px, 3.5vw, 32px); }
h3 { font-size: 20px; }

p { margin: 0 0 1em; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ============== HEADER ============== */
header.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.85); backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
header.site-header .inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; max-width: var(--container); margin: 0 auto; padding: 0 24px;
}
header .brand { font-family: var(--font-display); font-size: 20px; font-weight: 700; color: var(--ink); letter-spacing: -0.02em; }
header .brand:hover { text-decoration: none; }
header nav { display: flex; gap: 28px; align-items: center; }
header nav a { color: var(--ink-soft); font-size: 14px; font-weight: 500; }
header nav a:hover { color: var(--ink); text-decoration: none; }
header nav a.active { color: var(--accent); }
header .auth-block { display: flex; gap: 10px; align-items: center; }
@media (max-width: 720px) {
  header nav { display: none; }
}

/* ============== BUTTONS ============== */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 20px; background: var(--accent); color: white; border: none;
  border-radius: var(--radius-sm); cursor: pointer; font-size: 14px; font-weight: 600;
  transition: all 0.2s; text-decoration: none;
}
.btn:hover { background: var(--accent-hover); color: white; text-decoration: none; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn.secondary { background: white; color: var(--ink); border: 1px solid var(--border); }
.btn.secondary:hover { background: var(--border-soft); color: var(--ink); }
.btn.ghost { background: transparent; color: var(--ink-soft); }
.btn.ghost:hover { background: var(--border-soft); color: var(--ink); transform: none; box-shadow: none; }
.btn.lg { padding: 14px 28px; font-size: 15px; }
.btn.sm { padding: 6px 12px; font-size: 13px; }

/* ============== HERO ============== */
.hero {
  padding: 60px 0 80px;
  background: radial-gradient(ellipse at top, rgba(39,84,255,0.06), transparent 60%);
}
.hero h1 { max-width: 720px; }
.hero .lead { font-size: clamp(16px, 2vw, 18px); color: var(--ink-soft); max-width: 600px; margin-bottom: 24px; }
.hero .ctas { display: flex; gap: 12px; flex-wrap: wrap; }

/* ============== CARDS / GRIDS ============== */
.section { padding: 56px 0; }
.section-head { display: flex; justify-content: space-between; align-items: flex-end; margin-bottom: 28px; flex-wrap: wrap; gap: 12px; }
.section-head .label { font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 1.5px; color: var(--accent); margin-bottom: 6px; }
.section-head h2 { margin: 0; }

.grid { display: grid; gap: 20px; }
.grid.cols-3 { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.grid.cols-2 { grid-template-columns: repeat(auto-fill, minmax(360px, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }

.path-card {
  background: var(--bg-elevated); border: 1px solid var(--border);
  border-radius: var(--radius); transition: all 0.2s;
  display: flex; flex-direction: column; gap: 10px; position: relative; overflow: hidden;
}
.path-card .body { padding: 24px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.path-card.has-cover .body { padding-top: 20px; }
.path-card .cover {
  display: block; aspect-ratio: 16 / 9; background: var(--border-soft);
  background-size: cover; background-position: center;
  border-bottom: 1px solid var(--border);
}
.path-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: var(--accent); text-decoration: none; }
.path-card .cat { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 1.5px; color: var(--accent); display: flex; align-items: center; gap: 6px; }
.path-card h3 { margin: 0 0 4px; color: var(--ink); }
.path-card p { color: var(--ink-soft); font-size: 14px; margin: 0 0 12px; flex-grow: 1; }
.path-card .meta { display: flex; gap: 14px; align-items: center; padding-top: 12px; border-top: 1px solid var(--border); font-size: 12px; color: var(--ink-dim); }
.path-card .meta .pill { background: var(--border-soft); padding: 3px 8px; border-radius: 100px; }

/* ============== FILTERS ============== */
.filter-bar {
  background: white; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px; display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 28px;
}
.filter-bar input[type=search], .filter-bar select {
  padding: 9px 12px; border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: white; min-width: 180px;
}
.filter-bar input[type=search]:focus, .filter-bar select:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft);
}
.filter-bar .pills { display: flex; gap: 6px; flex-wrap: wrap; }
.filter-bar .pill-link {
  padding: 7px 14px; border-radius: 100px; background: var(--border-soft);
  color: var(--ink-soft); font-size: 13px; font-weight: 500; transition: all 0.15s;
}
.filter-bar .pill-link:hover { background: var(--border); text-decoration: none; }
.filter-bar .pill-link.active { background: var(--ink); color: white; }

/* ============== BREADCRUMB ============== */
.breadcrumb { display: flex; gap: 8px; align-items: center; font-size: 13px; color: var(--ink-dim); margin-bottom: 18px; flex-wrap: wrap; }
.breadcrumb a { color: var(--ink-soft); }
.breadcrumb .sep { color: var(--ink-faint); }

/* ============== COURSE/LESSON DETAIL ============== */
.detail-hero { padding: 40px 0 28px; border-bottom: 1px solid var(--border); }
.detail-hero h1 { margin: 0 0 12px; max-width: 760px; }
.detail-hero .tagline { font-size: 18px; color: var(--ink-soft); max-width: 700px; margin-bottom: 18px; }
.detail-hero .meta-row { display: flex; gap: 24px; flex-wrap: wrap; font-size: 14px; color: var(--ink-dim); }
.detail-hero .meta-row strong { color: var(--ink); }

/* ============== LESSON LIST ============== */
.lesson-list { display: flex; flex-direction: column; gap: 8px; margin-top: 24px; }
.lesson-row {
  display: flex; align-items: center; gap: 16px;
  background: white; border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 16px 20px;
  transition: all 0.15s;
}
.lesson-row:hover { border-color: var(--accent); transform: translateX(2px); text-decoration: none; box-shadow: var(--shadow-sm); }
.lesson-row .num {
  flex: 0 0 36px; height: 36px; border-radius: 50%; background: var(--border-soft);
  color: var(--ink-soft); display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 14px;
}
.lesson-row.completed .num { background: var(--success-soft); color: var(--success); }
.lesson-row.in-progress .num { background: var(--accent-soft); color: var(--accent); }
.lesson-row .body { flex: 1; min-width: 0; }
.lesson-row .body .title { color: var(--ink); font-weight: 600; font-size: 15px; margin: 0; }
.lesson-row .body .meta { color: var(--ink-dim); font-size: 12px; margin-top: 2px; }
.lesson-row .arrow { color: var(--ink-faint); }

/* ============== PROGRESS BAR ============== */
.progress-bar { height: 6px; background: var(--border-soft); border-radius: 100px; overflow: hidden; margin: 6px 0; }
.progress-bar .fill { height: 100%; background: linear-gradient(90deg, var(--accent), #4f7dff); border-radius: 100px; transition: width 0.6s ease; }

/* ============== LESSON PLAYER ============== */
body.lesson-player-page { background: #0a0c11; }
.player-shell { display: grid; grid-template-columns: 280px 1fr; height: 100vh; }
.player-sidebar {
  background: #11141b; border-right: 1px solid rgba(255,255,255,0.06);
  display: flex; flex-direction: column; overflow: hidden;
}
.player-sidebar .sidebar-head { padding: 18px; border-bottom: 1px solid rgba(255,255,255,0.06); }
.player-sidebar .sidebar-head a { color: #9ca3af; font-size: 12px; }
.player-sidebar .sidebar-head h3 { color: white; font-family: var(--font-body); font-size: 14px; margin: 8px 0 0; line-height: 1.3; }
.player-sidebar .sidebar-list { flex: 1; overflow-y: auto; padding: 8px 0; }
.player-sidebar .lesson-item {
  display: flex; gap: 10px; padding: 10px 18px; color: #c8ccd4; font-size: 13px;
  border-left: 3px solid transparent; align-items: center;
}
.player-sidebar .lesson-item:hover { background: rgba(255,255,255,0.04); color: white; text-decoration: none; }
.player-sidebar .lesson-item.active { background: rgba(39,84,255,0.15); color: white; border-left-color: var(--accent); }
.player-sidebar .lesson-item .num { flex: 0 0 22px; height: 22px; border-radius: 50%; background: rgba(255,255,255,0.06); display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; }
.player-sidebar .lesson-item.completed .num { background: var(--success); color: white; }
.player-main { display: flex; flex-direction: column; overflow: hidden; }
.player-topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 20px; background: #0f1117; border-bottom: 1px solid rgba(255,255,255,0.06);
  color: #c8ccd4; font-size: 13px;
}
.player-topbar .stat { display: flex; gap: 6px; align-items: center; }
.player-topbar .stat .v { color: white; font-weight: 700; }
.player-iframe { flex: 1; border: 0; width: 100%; background: white; }
@media (max-width: 768px) {
  .player-shell { grid-template-columns: 1fr; }
  .player-sidebar { display: none; }
  .player-sidebar.mobile-open { display: flex; position: fixed; inset: 0; z-index: 200; }
}

/* ============== DASHBOARD ============== */
.dash-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; margin-bottom: 32px; }
.dash-stat {
  background: white; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; display: flex; flex-direction: column; gap: 4px;
}
.dash-stat .label { color: var(--ink-dim); font-size: 12px; text-transform: uppercase; letter-spacing: 1.5px; font-weight: 600; }
.dash-stat .value { font-size: 32px; font-weight: 700; font-family: var(--font-display); color: var(--ink); letter-spacing: -0.02em; }
.dash-stat .sub { color: var(--ink-dim); font-size: 13px; }

/* ============== AUTH ============== */
body.auth-page {
  min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px;
  background: linear-gradient(135deg, #f8f9fc 0%, #eef2ff 100%);
}
.auth-card { background: white; padding: 36px; border-radius: var(--radius); box-shadow: var(--shadow-lg); max-width: 420px; width: 100%; }
.auth-card h1 { font-size: 24px; margin: 0 0 4px; }
.auth-card .subtitle { color: var(--ink-dim); margin-bottom: 24px; font-size: 14px; }
.auth-card label { display: block; font-size: 13px; font-weight: 500; margin: 14px 0 6px; }
.auth-card input { width: 100%; padding: 11px 12px; border: 1px solid var(--border); border-radius: var(--radius-sm); }
.auth-card input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.auth-card .btn { width: 100%; justify-content: center; margin-top: 18px; }
.auth-card .toggle { text-align: center; margin-top: 18px; font-size: 14px; color: var(--ink-dim); }
.auth-error { background: #fee2e2; color: #991b1b; padding: 10px 12px; border-radius: var(--radius-sm); font-size: 13px; margin-bottom: 12px; }
.auth-success { background: var(--success-soft); color: var(--success); padding: 10px 12px; border-radius: var(--radius-sm); font-size: 13px; margin-bottom: 12px; }

/* ============== FOOTER ============== */
footer.site-footer {
  background: #0f1117; color: #9ca3af; padding: 48px 0 32px; margin-top: 80px; font-size: 14px;
}
footer.site-footer .inner { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
footer.site-footer .top { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 24px; padding-bottom: 28px; border-bottom: 1px solid rgba(255,255,255,0.06); }
footer.site-footer .brand { font-family: var(--font-display); font-size: 20px; color: white; }
footer.site-footer .links { display: flex; gap: 28px; flex-wrap: wrap; }
footer.site-footer a { color: #9ca3af; }
footer.site-footer a:hover { color: white; text-decoration: none; }
footer.site-footer .copy { padding-top: 20px; color: #6b7280; font-size: 12px; }

/* ============== UTILITY ============== */
.text-muted { color: var(--ink-dim); }
.text-sm { font-size: 13px; }
.text-lg { font-size: 17px; }
.muted { color: var(--ink-dim); }
.mt-0 { margin-top: 0; } .mt-2 { margin-top: 16px; } .mt-4 { margin-top: 32px; }
.mb-0 { margin-bottom: 0; } .mb-2 { margin-bottom: 16px; } .mb-4 { margin-bottom: 32px; }
.tag { display: inline-block; padding: 3px 10px; border-radius: 100px; font-size: 12px; font-weight: 500; background: var(--border-soft); color: var(--ink-soft); }
.tag.success { background: var(--success-soft); color: var(--success); }
.empty-state { text-align: center; padding: 80px 20px; color: var(--ink-dim); }
.empty-state h3 { color: var(--ink); }
.flash { padding: 12px 16px; border-radius: var(--radius-sm); margin-bottom: 18px; font-size: 14px; }
.flash.success { background: var(--success-soft); color: var(--success); }
.flash.error { background: #fee2e2; color: #991b1b; }