/* ====== تم شب (پیش‌فرض) ====== */
:root,
[data-theme="dark"] {
  --bg: #0b1220;
  --bg-image: radial-gradient(circle at 20% 10%, #1a2740 0%, #0b1220 60%);
  --bg-overlay: rgba(6, 12, 24, 0.15);
  --bg-opacity: 1;

  --text: #e6eefc;
  --text-muted: #8fa3c0;

  --glass: rgba(22, 32, 52, 0.55);
  --glass-strong: rgba(22, 32, 52, 0.85);
  --glass-border: rgba(255, 255, 255, 0.07);

  --accent: #5b8def;
  --accent-2: #a855f7;
  --success: #22c55e;
  --danger: #ef4444;
  --warning: #f59e0b;

  --scroll: rgba(140, 160, 200, 0.35);
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
}

/* ====== تم روز ====== */
[data-theme="light"] {
  --bg: #dff0ff;
  --bg-image: url("../images/day-bg.jpg"),
               linear-gradient(180deg, #87cefa 0%, #bfe6ff 55%, #7ecb6b 100%);
  --bg-overlay: rgba(255, 255, 255, 0.06);
  --bg-opacity: 1;

  --text: #10203a;
  --text-muted: #4a5a75;

  --glass: rgba(255, 255, 255, 0.45);
  --glass-strong: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(255, 255, 255, 0.6);

  --accent: #2563eb;
  --accent-2: #7c3aed;
  --success: #16a34a;
  --danger: #dc2626;
  --warning: #d97706;

  --scroll: rgba(40, 60, 100, 0.28);
  --shadow: 0 10px 40px rgba(50, 80, 130, 0.18);
}

/* ترنزیشن نرم بین تم‌ها */
*,
*::before,
*::after {
  transition:
    background-color .6s ease,
    border-color .6s ease,
    color .6s ease,
    box-shadow .6s ease,
    fill .6s ease,
    stroke .6s ease;
}