/* ==========================================================================
   THEMES.CSS — Atelier Polytech Design Tokens & Theme Switcher
   Dark mode (default) · Light mode via [data-theme='light']
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. DARK MODE (Default) - Premium Black & White
   -------------------------------------------------------------------------- */
:root {
  /* — Backgrounds (Pure Black & Charcoal) — */
  --bg-primary: #000000;
  --bg-secondary: #0d0d0d;
  --bg-tertiary: #1a1a1a;
  --bg-card: rgba(13, 13, 13, 0.95);
  --bg-card-hover: rgba(26, 26, 26, 0.98);

  /* — Typography (Pure White to Grays) — */
  --text-primary: #ffffff;
  --text-secondary: #d4d4d4;
  --text-muted: #a3a3a3;

  /* — Accent / Brand (Pure White with subtle effects) — */
  --accent: #ffffff;
  --accent-hover: #f5f5f5;
  --accent-dark: #e5e5e5;
  --accent-glow: rgba(255, 255, 255, 0.15);
  --accent-glow-strong: rgba(255, 255, 255, 0.25);

  /* — Gradients (Black to White) — */
  --gradient-hero: radial-gradient(circle at center, rgba(0, 0, 0, 0.9) 0%, rgba(0, 0, 0, 0.7) 40%, rgba(0, 0, 0, 0.3) 100%);
  --gradient-accent: linear-gradient(135deg, #ffffff, #e5e5e5);
  --gradient-card: linear-gradient(135deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));

  /* — Borders (Subtle White) — */
  --border-color: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(255, 255, 255, 0.3);

  /* — Shadows (Deep Black) — */
  --shadow-sm: 0 2px 16px rgba(0, 0, 0, 0.8);
  --shadow-md: 0 4px 32px rgba(0, 0, 0, 0.9);
  --shadow-lg: 0 8px 64px rgba(0, 0, 0, 0.95);
  --shadow-glow: 0 0 40px rgba(255, 255, 255, 0.15);

  /* — Glassmorphism (Black with transparency) — */
  --glass-bg: rgba(13, 13, 13, 0.8);
  --glass-border: rgba(255, 255, 255, 0.1);

  /* — Navigation (Pure Black) — */
  --nav-bg: rgba(0, 0, 0, 0.95);

  /* — Button text (contrast against gradient-accent) — */
  --btn-primary-text: #000000;

  /* — Color scheme hint for browser — */
  color-scheme: dark;
}

/* --------------------------------------------------------------------------
   2. LIGHT MODE — Premium White & Gray
   -------------------------------------------------------------------------- */
[data-theme='light'] {
  /* — Backgrounds (Pure White & Light Grays) — */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f8f8;
  --bg-tertiary: #f0f0f0;
  --bg-card: rgba(255, 255, 255, 0.95);
  --bg-card-hover: #ffffff;

  /* — Typography (Black to Grays) — */
  --text-primary: #000000;
  --text-secondary: #525252;
  --text-muted: #737373;

  /* — Accent / Brand (Pure Black) — */
  --accent: #000000;
  --accent-hover: #1a1a1a;
  --accent-dark: #0d0d0d;
  --accent-glow: rgba(0, 0, 0, 0.08);
  --accent-glow-strong: rgba(0, 0, 0, 0.15);

  /* — Gradients (White to Gray) — */
  --gradient-hero: radial-gradient(circle at center, rgba(255, 255, 255, 0.95) 0%, rgba(255, 255, 255, 0.75) 45%, rgba(255, 255, 255, 0.3) 100%);
  --gradient-accent: linear-gradient(135deg, #000000, #1a1a1a);
  --gradient-card: linear-gradient(135deg, rgba(0, 0, 0, 0.04), rgba(0, 0, 0, 0.01));

  /* — Borders (Subtle Black) — */
  --border-color: rgba(0, 0, 0, 0.08);
  --border-accent: rgba(0, 0, 0, 0.2);

  /* — Shadows (Soft Black) — */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 24px rgba(0, 0, 0, 0.05);

  /* — Glassmorphism (White with transparency) — */
  --glass-bg: rgba(255, 255, 255, 0.9);
  --glass-border: rgba(0, 0, 0, 0.08);

  /* — Navigation (Pure White) — */
  --nav-bg: rgba(255, 255, 255, 0.95);

  /* — Button text (contrast against gradient-accent) — */
  --btn-primary-text: #ffffff;

  /* — Color scheme hint for browser — */
  color-scheme: light;
}

/* --------------------------------------------------------------------------
   3. GLOBAL THEME TRANSITION
   Smooth cross-fade when switching themes.
   We intentionally EXCLUDE transform & opacity so scroll/hover
   animations remain GPU-accelerated and jank-free.
   -------------------------------------------------------------------------- */
* {
  transition:
    background-color 0.4s ease,
    color 0.3s ease,
    border-color 0.3s ease,
    box-shadow 0.3s ease;
}

/* --------------------------------------------------------------------------
   4. THEME TOGGLE BUTTON
   Circular button housing a sun / moon icon swap.
   Expected markup:
     <button class="theme-toggle" aria-label="Toggle theme">
       <span class="theme-toggle__icon theme-toggle__icon--sun">☀️</span>
       <span class="theme-toggle__icon theme-toggle__icon--moon">🌙</span>
     </button>
   -------------------------------------------------------------------------- */
.theme-toggle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--glass-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  cursor: pointer;
  overflow: hidden;
  outline: none;
  z-index: 1001;
  flex-shrink: 0;
}

/* Subtle glow ring on hover */
.theme-toggle:hover {
  box-shadow: var(--shadow-glow);
}

/* Focus-visible for keyboard accessibility */
.theme-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ---------- Icon base ---------- */
.theme-toggle__icon {
  position: absolute;
  top: 50%;
  left: 50%;
  stroke: var(--text-primary);
  transition:
    transform 0.45s cubic-bezier(0.4, 0, 0.2, 1),
    opacity 0.35s ease;
  will-change: transform, opacity;
}

/* ---------- Dark mode (default): show Moon, hide Sun ---------- */
.theme-toggle__icon--moon {
  margin-top: -9px;
  margin-left: -9px;
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.theme-toggle__icon--sun {
  margin-top: -10px;
  margin-left: -10px;
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

/* ---------- Light mode: show Sun, hide Moon ---------- */
[data-theme='light'] .theme-toggle__icon--moon {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

[data-theme='light'] .theme-toggle__icon--sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* ---------- Active press micro-feedback ---------- */
.theme-toggle:active {
  transform: scale(0.92);
}

/* ==========================================================================
   5. THEME-AWARE LOGO FILTERS
   Inverts black logo.png to white in dark mode (default), keeping it black
   in light mode. Also integrates drop-shadow glows for featured displays.
   ========================================================================== */

/* Dark mode (default): Invert black logo to white */
.logo-invert {
  filter: invert(1);
}

.logo-invert-shadow-md {
  filter: invert(1) drop-shadow(0 0 30px var(--accent-glow));
}

.logo-invert-shadow-lg {
  filter: invert(1) drop-shadow(0 0 40px var(--accent-glow-strong));
}

/* Light mode: Keep black logo as black */
[data-theme='light'] .logo-invert {
  filter: invert(0);
}

[data-theme='light'] .logo-invert-shadow-md {
  filter: invert(0) drop-shadow(0 0 30px var(--accent-glow));
}

[data-theme='light'] .logo-invert-shadow-lg {
  filter: invert(0) drop-shadow(0 0 40px var(--accent-glow-strong));
}