/**
 * Dark Mode Overrides — Event 4
 * Text, surfaces, and section backgrounds tuned for readability.
 */

[data-bs-theme="dark"] {
  color-scheme: dark;

  --md-sys-color-primary: #38bdf8;
  --md-sys-color-on-primary: #0c1929;
  --md-sys-color-primary-container: #0c4a6e;
  --md-sys-color-on-primary-container: #bae6fd;

  --md-sys-color-surface: #0c1929;
  --md-sys-color-on-surface: #e0f2fe;
  --md-sys-color-surface-variant: #1e293b;
  --md-sys-color-on-surface-variant: #94a3b8;

  --md-sys-color-background: #0a0f1a;
  --md-sys-color-on-background: #e0f2fe;

  --grad-sky-1: #0c1929;
  --grad-sky-2: #1e293b;
  --grad-sky-3: #0c4a6e;
  --grad-sky-4: #1e3a5f;

  --glass-bg: rgba(15, 23, 42, 0.75);
  --glass-border: rgba(255, 255, 255, 0.08);

  --bg-primary: rgba(12, 25, 41, 0.85);
  --bg-secondary: rgba(15, 23, 42, 0.9);
  --bg-card: rgba(30, 41, 59, 0.75);
  --bg-card-hover: rgba(30, 41, 59, 0.95);
  --border: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(56, 189, 248, 0.25);

  --grad-primary: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  --grad-subtle: linear-gradient(
    135deg,
    rgba(56, 189, 248, 0.1) 0%,
    rgba(129, 140, 248, 0.1) 100%
  );
  --grad-light: linear-gradient(180deg, #0c1929 0%, #1e293b 100%);

  --accent-blue: #38bdf8;
  --accent-purple: #a5b4fc;
  --accent-gold: #fbbf24;
  --accent-teal: #2dd4bf;

  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;

  --shadow-glow: 0 10px 30px rgba(56, 189, 248, 0.08);
  --shadow-card:
    0 10px 25px -5px rgba(0, 0, 0, 0.35),
    0 8px 10px -6px rgba(0, 0, 0, 0.25);
  --shadow-btn: 0 8px 25px rgba(129, 140, 248, 0.25);
}

/* --- Navigation --- */
[data-bs-theme="dark"] #navbar.scrolled {
  background: rgba(12, 25, 41, 0.92);
  border-bottom-color: var(--border);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
}

[data-bs-theme="dark"] .mobile-nav {
  background: rgba(12, 25, 41, 0.98);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
}

[data-bs-theme="dark"] .hamburger span {
  background: var(--text-primary);
}

/* --- Hero --- */
[data-bs-theme="dark"] #hero .hero-bg::after {
  background: linear-gradient(
    180deg,
    rgba(12, 25, 41, 0.35) 0%,
    rgba(12, 25, 41, 0.95) 100%
  );
}

[data-bs-theme="dark"] .badge-free {
  background: rgba(56, 189, 248, 0.12);
  border-color: rgba(56, 189, 248, 0.28);
}

[data-bs-theme="dark"] .badge-online {
  background: rgba(129, 140, 248, 0.12);
  border-color: rgba(129, 140, 248, 0.28);
}

[data-bs-theme="dark"] .badge-bangla {
  background: rgba(251, 191, 36, 0.12);
  border-color: rgba(251, 191, 36, 0.28);
}

[data-bs-theme="dark"] .badge-gmeet {
  background: rgba(45, 212, 191, 0.12);
  border-color: rgba(45, 212, 191, 0.28);
}

[data-bs-theme="dark"] .badge-duration {
  background: rgba(129, 140, 248, 0.12);
  border-color: rgba(129, 140, 248, 0.28);
}

/* --- Section backgrounds (match dark text tokens) --- */
[data-bs-theme="dark"] #about,
[data-bs-theme="dark"] #speaker,
[data-bs-theme="dark"] #register,
[data-bs-theme="dark"] #community,
[data-bs-theme="dark"] #sponsors {
  background: rgba(15, 23, 42, 0.72);
}

[data-bs-theme="dark"] #learn,
[data-bs-theme="dark"] #agenda,
[data-bs-theme="dark"] #certificate {
  background: rgba(12, 25, 41, 0.68);
}

/* --- Forms --- */
[data-bs-theme="dark"] .form-group input,
[data-bs-theme="dark"] .form-group select,
[data-bs-theme="dark"] .form-group textarea {
  background: #1e293b;
  color: var(--text-primary);
  border-color: var(--border);
}

[data-bs-theme="dark"] .form-group input::placeholder {
  color: var(--text-muted);
}

[data-bs-theme="dark"] .form-group input:focus,
[data-bs-theme="dark"] .form-group select:focus,
[data-bs-theme="dark"] .form-group textarea:focus {
  background: rgba(30, 41, 59, 0.95);
  box-shadow: 0 0 0 3px rgba(129, 140, 248, 0.18);
}

[data-bs-theme="dark"] .form-group select option {
  background: #1e293b;
  color: var(--text-primary);
}

/* --- Agenda & cards --- */
[data-bs-theme="dark"] .tl-special {
  border-color: rgba(251, 191, 36, 0.35) !important;
  background: rgba(251, 191, 36, 0.06) !important;
}

[data-bs-theme="dark"] .sponsor-badge {
  background: rgba(251, 191, 36, 0.12);
  border-color: rgba(251, 191, 36, 0.3);
}

[data-bs-theme="dark"] .org-tag {
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

[data-bs-theme="dark"] .btn-secondary {
  background: rgba(255, 255, 255, 0.04);
}

[data-bs-theme="dark"] .btn-secondary:hover {
  background: rgba(129, 140, 248, 0.1);
}

[data-bs-theme="dark"] .perk-check {
  background: rgba(129, 140, 248, 0.12);
}

[data-bs-theme="dark"] .yt-thumb {
  background: rgba(255, 0, 0, 0.12);
  border-color: rgba(255, 0, 0, 0.22);
}

[data-bs-theme="dark"] .yt-card:hover .yt-thumb {
  background: rgba(255, 0, 0, 0.2);
  border-color: rgba(255, 0, 0, 0.35);
}

[data-bs-theme="dark"] .calendar-cta {
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

/* --- Footer --- */
[data-bs-theme="dark"] #footer {
  background: #0a0f1a;
}