/* ─── Design Tokens ─── */
:root {
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-display: 'Space Grotesk', system-ui, sans-serif;

  /* Dark theme (default) */
  --bg: #0d0d0d;
  --bg-2: #141414;
  --bg-3: #1c1c1c;
  --border: rgba(255,255,255,0.08);
  --text: #f0f0f0;
  --text-2: #888;
  --text-3: #555;
  --accent: #6b7dff;
  --accent-hover: #8490ff;
  --logo-color: #f0f0f0;
}

[data-theme="light"] {
  --bg: #ffffff;
  --bg-2: #f5f5f5;
  --bg-3: #ebebeb;
  --border: rgba(0,0,0,0.09);
  --text: #111111;
  --text-2: #555;
  --text-3: #999;
  --accent: #4a5af0;
  --accent-hover: #3344e0;
  --logo-color: #111111;
}

/* ─── Reset ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.2s, color 0.2s;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
main { flex: 1; padding-top: 64px; }

/* ─── Header ─── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 32px;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--logo-color);
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  flex-shrink: 0;
}
.logo svg { color: var(--accent); }
.logo span { color: var(--text); }
.logo strong { color: var(--accent); font-weight: 700; }

/* Nav */
.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 8px;
}
.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-2);
  padding: 6px 12px;
  border-radius: 8px;
  transition: color 0.15s, background 0.15s;
}
.nav-link:hover {
  color: var(--text);
  background: var(--bg-3);
}

/* Header actions */
.header-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Theme toggle */
.theme-toggle {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-2);
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  position: relative;
}
.theme-toggle:hover {
  background: var(--bg-3);
  color: var(--text);
  border-color: var(--accent);
}
.icon-sun, .icon-moon {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.2s, transform 0.2s;
}
/* Dark mode: show sun (to switch to light) */
[data-theme="dark"] .icon-sun  { opacity: 1; transform: scale(1); }
[data-theme="dark"] .icon-moon { opacity: 0; transform: scale(0.5); }
/* Light mode: show moon (to switch to dark) */
[data-theme="light"] .icon-sun  { opacity: 0; transform: scale(0.5); }
[data-theme="light"] .icon-moon { opacity: 1; transform: scale(1); }

/* ─── Footer ─── */
.site-footer {
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  margin-top: 80px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 56px 24px 32px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 64px;
  margin-bottom: 48px;
}

.footer-brand .logo {
  margin-bottom: 16px;
  display: inline-flex;
}

.footer-desc {
  font-size: 0.875rem;
  color: var(--text-2);
  line-height: 1.7;
  max-width: 280px;
  margin-bottom: 20px;
}

.footer-social {
  display: flex;
  gap: 12px;
}
.footer-social a {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-2);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}
.footer-social a:hover {
  color: var(--text);
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, var(--bg-3));
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-col h4 {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 16px;
}

.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a {
  font-size: 0.875rem;
  color: var(--text-2);
  transition: color 0.15s;
}
.footer-col a:hover { color: var(--accent); }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-copy, .footer-note {
  font-size: 0.8rem;
  color: var(--text-3);
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  .site-nav { display: none; }
  .footer-top { grid-template-columns: 1fr; gap: 40px; }
  .footer-links { grid-template-columns: repeat(2, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 480px) {
  .footer-links { grid-template-columns: 1fr; }
}


/* ─── Search Trigger Button ─── */
.search-trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  padding: 6px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
  white-space: nowrap;
}
.search-trigger:hover { border-color: var(--accent); color: var(--text); }
.search-trigger kbd {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  color: var(--text-3);
}
@media (max-width: 600px) {
  .search-trigger span, .search-trigger kbd { display: none; }
  .search-trigger { padding: 7px; }
}

/* ─── Language Switcher ─── */
.lang-switcher {
  position: relative;
}
.lang-current {
  display: flex;
  align-items: center;
  gap: 4px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.lang-current:hover, .lang-switcher.open .lang-current {
  border-color: var(--accent);
  color: var(--text);
}
.lang-dropdown {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 6px;
  min-width: 160px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.25);
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition: opacity 0.15s, transform 0.15s, visibility 0.15s;
  z-index: 200;
  visibility: hidden;
}
.lang-switcher.open .lang-dropdown {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
  visibility: visible;
}
.lang-option {
  display: block;
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 0.875rem;
  color: var(--text-2);
  transition: background 0.1s, color 0.1s;
  cursor: pointer;
}
.lang-option:hover { background: var(--bg-3); color: var(--text); }
.lang-option.active { color: var(--accent); font-weight: 500; }

/* ─── Search Modal ─── */
.search-modal {
  position: fixed;
  inset: 0;
  z-index: 999;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 80px;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.15s, visibility 0.15s;
}
.search-modal.is-open {
  visibility: visible;
  opacity: 1;
}

.search-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
}
.search-box {
  position: relative;
  z-index: 1;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  width: 100%;
  max-width: 560px;
  margin: 0 16px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.4);
  overflow: hidden;
}
.search-input-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  color: var(--text-3);
}
.search-input-wrap input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--text);
}
.search-input-wrap input::placeholder { color: var(--text-3); }
.search-close {
  background: var(--bg-3);
  border: 1px solid var(--border);
  color: var(--text-3);
  font-size: 0.7rem;
  padding: 2px 7px;
  border-radius: 5px;
  cursor: pointer;
  font-family: var(--font-sans);
}
.search-results { padding: 12px; min-height: 80px; }
.search-hint { color: var(--text-3); font-size: 0.85rem; padding: 12px 8px; }
.search-result-item {
  display: block;
  padding: 10px 12px;
  border-radius: 8px;
  color: var(--text);
  font-size: 0.9rem;
  transition: background 0.1s;
}
.search-result-item:hover { background: var(--bg-3); }
.search-result-item .result-title { font-weight: 500; margin-bottom: 2px; }
.search-result-item .result-excerpt { font-size: 0.8rem; color: var(--text-2); }
/* ─── Hamburger ─── */
.hamburger {
  display: none;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 36px;
  height: 36px;
  padding: 8px;
  cursor: pointer;
}
.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-2);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ─── Mobile Menu ─── */
.mobile-menu {
  border-top: 1px solid var(--border);
  background: var(--bg);
  padding: 16px 24px 24px;
}
.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 20px;
}
.mobile-nav-link {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-2);
  padding: 10px 12px;
  border-radius: 8px;
  transition: background 0.15s, color 0.15s;
}
.mobile-nav-link:hover { background: var(--bg-3); color: var(--text); }

.mobile-langs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.mobile-lang {
  font-size: 0.85rem;
  color: var(--text-2);
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
  transition: border-color 0.15s, color 0.15s;
}
.mobile-lang:hover { border-color: var(--accent); color: var(--text); }
.mobile-lang.active { border-color: var(--accent); color: var(--accent); font-weight: 500; }

@media (max-width: 768px) {
  .hamburger { display: flex; }
  .site-nav { display: none; }
  .lang-switcher { display: none; }
  .search-label, .search-kbd { display: none; }
  .search-trigger { padding: 8px; }
}

/* ─── Hamburger ─── */
.hamburger {
  display: none;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  padding: 8px;
}
.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-2);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ─── Mobile Menu ─── */
.mobile-menu {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px 24px;
}
.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 20px;
}
.mobile-nav-link {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-2);
  padding: 10px 12px;
  border-radius: 8px;
  transition: background 0.15s, color 0.15s;
}
.mobile-nav-link:hover { background: var(--bg-3); color: var(--text); }
.mobile-langs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.mobile-lang-option {
  font-size: 0.85rem;
  color: var(--text-2);
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
  transition: border-color 0.15s, color 0.15s;
}
.mobile-lang-option:hover { border-color: var(--accent); color: var(--text); }
.mobile-lang-option.active { border-color: var(--accent); color: var(--accent); font-weight: 500; }

@media (max-width: 768px) {
  .site-nav { display: none; }
  .search-label, .search-kbd { display: none; }
  .search-trigger { padding: 8px; }
  .lang-switcher { display: none; }
  .hamburger { display: flex; }
}