/* ═══════════════════════════════════════════════════════════
   Astratera — Global Design System
   Palette:  #080a0c  background deep
             #0e1416  surface
             #141e1e  surface raised
             #1a2e2e  border/divider
             #00b8b8  accent teal (from logo)
             #00d4d4  accent teal light
             #006666  accent teal muted
             #c8d8d8  text primary
             #6a9090  text secondary
             #3a5050  text disabled
   ═══════════════════════════════════════════════════════════ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg-deep:     #080a0c;
  --bg-surface:  #0e1416;
  --bg-raised:   #141e1e;
  --border:      #1a2e2e;
  --border-bright: #254040;
  --accent:      #00b8b8;
  --accent-light: #00d4d4;
  --accent-dim:  #006666;
  --accent-glow: rgba(0, 184, 184, 0.12);
  --text-primary: #c8d8d8;
  --text-secondary: #6a9090;
  --text-disabled: #3a5050;
  --danger:      #c04040;
  --success:     #00b8b8;

  --nav-width:   220px;
  --nav-width-collapsed: 0px;
  --topbar-h:    52px;

  --font-ui:     'Inter', 'Segoe UI', system-ui, sans-serif;
  --font-mono:   'JetBrains Mono', 'Consolas', monospace;

  --radius-sm:   4px;
  --radius:      6px;
  --radius-lg:   10px;

  --transition:  150ms ease;
}

html, body {
  height: 100%;
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ── Typography ───────────────────────────────────────────── */
h1, h2, h3, h4 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.3;
}
h1 { font-size: 1.5rem; }
h2 { font-size: 1.2rem; }
h3 { font-size: 1rem; }

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-light); }

code, .mono {
  font-family: var(--font-mono);
  font-size: 0.85em;
}

/* ── Layout shell ─────────────────────────────────────────── */
.app-shell {
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar navigation ───────────────────────────────────── */
.sidebar {
  width: var(--nav-width);
  min-height: 100vh;
  background: var(--bg-surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
  transition: transform var(--transition);
}

.sidebar-logo {
  padding: 20px 16px 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-logo img {
  width: 100%;
  max-width: 140px;
  display: block;
  margin: 0 auto;
  opacity: 0.9;
}

.sidebar-nav {
  flex: 1;
  padding: 12px 8px;
  overflow-y: auto;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
  overflow: hidden;
  position: relative;
}
.nav-item:hover {
  background: var(--accent-glow);
  color: var(--text-primary);
}
.nav-item.active {
  background: var(--accent-glow);
  color: var(--accent);
}
.nav-item.active::before {
  content: '';
  position: absolute;
  left: 0; top: 20%; bottom: 20%;
  width: 2px;
  background: var(--accent);
  border-radius: 2px;
}
.nav-icon {
  font-size: 1rem;
  width: 18px;
  text-align: center;
  flex-shrink: 0;
}
.nav-label { flex: 1; }
.nav-badge {
  font-size: 0.7rem;
  background: var(--border);
  color: var(--text-secondary);
  padding: 1px 6px;
  border-radius: 10px;
}

.nav-soon {
  font-size: 0.65rem;
  color: var(--text-disabled);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sidebar-footer {
  padding: 12px 8px;
  border-top: 1px solid var(--border);
}
.sidebar-user {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: var(--radius);
}
.sidebar-user-name {
  flex: 1;
  font-size: 0.85rem;
  color: var(--text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sidebar-logout {
  font-size: 0.8rem;
  color: var(--text-disabled);
  text-decoration: none;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.sidebar-logout:hover {
  color: var(--danger);
  background: rgba(192, 64, 64, 0.08);
}

/* Mobile hamburger */
.hamburger {
  display: none;
  position: fixed;
  top: 12px; left: 12px;
  z-index: 200;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  color: var(--text-primary);
  width: 36px; height: 36px;
  border-radius: var(--radius);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 99;
}

/* ── Main content area ────────────────────────────────────── */
.main {
  margin-left: var(--nav-width);
  flex: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.page-header {
  padding: 28px 32px 20px;
  border-bottom: 1px solid var(--border);
}
.page-header h1 { font-size: 1.3rem; }
.page-header .sub {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-top: 4px;
}

.page-content {
  padding: 28px 32px;
  flex: 1;
}

/* ── Cards ────────────────────────────────────────────────── */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
}
.card + .card { margin-top: 16px; }

/* ── Session list cards ───────────────────────────────────── */
.session-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.session-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  cursor: pointer;
  text-decoration: none;
  display: block;
  transition: border-color var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
}
.session-card:hover {
  border-color: var(--accent-dim);
  background: var(--bg-raised);
  color: inherit;
}
.session-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
  opacity: 0;
  transition: opacity var(--transition);
}
.session-card:hover::after { opacity: 1; }

.session-card-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.session-card-meta {
  font-size: 0.78rem;
  color: var(--text-secondary);
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.session-card-progress {
  margin-top: 14px;
  height: 2px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}
.session-card-progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.3s ease;
}
.session-card-resume {
  margin-top: 10px;
  font-size: 0.75rem;
  color: var(--accent);
}

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: background var(--transition), color var(--transition);
  text-decoration: none;
  font-family: var(--font-ui);
}
.btn-primary {
  background: var(--accent);
  color: #080a0c;
}
.btn-primary:hover { background: var(--accent-light); color: #080a0c; }

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  background: var(--bg-raised);
  color: var(--text-primary);
  border-color: var(--border-bright);
}
.btn-danger {
  background: rgba(192,64,64,0.12);
  color: #e08080;
  border: 1px solid rgba(192,64,64,0.2);
}
.btn-danger:hover { background: rgba(192,64,64,0.22); }
.btn:disabled { opacity: 0.4; cursor: default; }

/* ── Forms ────────────────────────────────────────────────── */
.form-group { margin-bottom: 16px; }
.form-label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 5px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.form-input {
  width: 100%;
  background: var(--bg-deep);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 9px 12px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-family: var(--font-ui);
  transition: border-color var(--transition);
}
.form-input:focus {
  outline: none;
  border-color: var(--accent);
}
.form-input::placeholder { color: var(--text-disabled); }

select.form-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236a9090' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}

/* ── Alerts ───────────────────────────────────────────────── */
.alert {
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 0.85rem;
  margin-bottom: 16px;
}
.alert-error {
  background: rgba(192,64,64,0.10);
  border: 1px solid rgba(192,64,64,0.25);
  color: #e08080;
}
.alert-success {
  background: rgba(0,184,184,0.08);
  border: 1px solid rgba(0,184,184,0.2);
  color: var(--accent);
}

/* ── Table ────────────────────────────────────────────────── */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.data-table th {
  text-align: left;
  padding: 8px 12px;
  color: var(--text-secondary);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-bottom: 1px solid var(--border);
  font-weight: 500;
}
.data-table td {
  padding: 11px 12px;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}
.data-table tr:last-child td { border-bottom: none; }
.data-table tr:hover td { background: var(--accent-glow); }

/* ── Coming soon placeholder ─────────────────────────────── */
.coming-soon {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 40px;
  text-align: center;
  color: var(--text-secondary);
}
.coming-soon .icon { font-size: 2.5rem; margin-bottom: 16px; opacity: 0.4; }
.coming-soon h2 { color: var(--text-secondary); font-size: 1rem; margin-bottom: 8px; }
.coming-soon p { font-size: 0.85rem; color: var(--text-disabled); max-width: 320px; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .sidebar-overlay.open {
    display: block;
  }
  .hamburger {
    display: flex;
  }
  .main {
    margin-left: 0;
  }
  .page-header, .page-content {
    padding: 20px 16px;
    padding-top: 60px;
  }
  .session-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  :root { --nav-width: 200px; }
  .page-header, .page-content { padding-left: 24px; padding-right: 24px; }
}

/* ── Scrollbar ────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-bright); }