:root {
  --bg-primary: #000000;
  --bg-secondary: #0a0a0a;
  --bg-tertiary: #111111;
  --bg-card: #1a1a1a;
  --bg-card-hover: #222222;
  --bg-input: #1a1a1a;

  --accent-primary: #D4AF37;
  --accent-secondary: #FFD700;

  --text-primary: #ffffff;
  --text-secondary: #b0b0b0;
  --text-muted: #666666;
  --text-inverse: #000000;

  --border-color: #2a2a2a;
  --border-light: #333333;

  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);

  --color-success: #22c55e;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  --font-primary: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, Oxygen, Ubuntu, sans-serif;
  --font-heading: 'Montserrat', 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Consolas', 'Monaco', 'Courier New', monospace;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;

  --header-height: 64px;
  --sidebar-width: 280px;
  --container-max: 1280px;
  --container-narrow: 900px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

.bg-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -3;
  pointer-events: none;
  background-image: url('../images/alchemy-factory-pc-bg.jpg');
  background-attachment: fixed;
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  opacity: 0.6;
  /* 底部加深，便于叠放内容 */
  overflow: hidden;
}

.bg-layer::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(0, 0, 0, 0) 0%,
    rgba(0, 0, 0, 0.6) 70%,
    rgba(0, 0, 0, 0.75) 100%
  );
}

html[data-theme="dark"] body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  pointer-events: none;
  background-color: rgba(0, 0, 0, 0.4);
}

html[data-theme="dark"] body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
  opacity: 0.12;
  background-image:
    linear-gradient(
      60deg,
      transparent 64%,
      rgba(150, 150, 150, 0.8) 64%,
      rgba(150, 150, 150, 0.8) 66%,
      transparent 66%
    ),
    linear-gradient(
      -60deg,
      transparent 64%,
      rgba(150, 150, 150, 0.8) 64%,
      rgba(150, 150, 150, 0.8) 66%,
      transparent 66%
    ),
    linear-gradient(
      60deg,
      rgba(150, 150, 150, 0.8) 34%,
      rgba(150, 150, 150, 0.8) 36%,
      transparent 36%
    ),
    linear-gradient(
      -60deg,
      rgba(150, 150, 150, 0.8) 34%,
      rgba(150, 150, 150, 0.8) 36%,
      transparent 36%
    );
  background-size: 80px 140px;
}


body > * {
  position: relative;
  z-index: 1;
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-secondary);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 { font-size: var(--font-size-4xl); font-weight: 800; }
h2 { font-size: var(--font-size-3xl); font-weight: 800; letter-spacing: -0.02em; }
h3 { font-size: var(--font-size-2xl); font-weight: 700; letter-spacing: -0.01em; }
h4 { font-size: var(--font-size-xl); font-weight: 700; }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

::selection {
  background-color: var(--accent-primary);
  color: var(--text-inverse);
}

:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.grid-auto {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

.site-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.main-content {
  flex: 1;
  padding: var(--space-2xl) 0;
}

.page-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 1024px) {
  .page-layout {
    grid-template-columns: 1fr var(--sidebar-width);
  }
}

.section {
  padding: var(--space-2xl) 0;
}

.section-header {
  margin-bottom: var(--space-xl);
  text-align: center;
}

.section-title {
  /* 统一全站 H2 级别标题字号，略大一些，和 HERO/导航视觉一致 */
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.guides-section-title {
  font-family: var(--font-heading);
  font-size: var(--font-size-3xl);
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: var(--font-size-lg);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-accent { color: var(--accent-primary); }

.bg-primary { background-color: var(--bg-primary); }
.bg-secondary { background-color: var(--bg-secondary); }
.bg-card { background-color: var(--bg-card); }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
    --font-size-2xl: 1.25rem;
  }

  .container {
    padding: 0 var(--space-md);
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .hide-mobile {
    display: none !important;
  }
}

@media (min-width: 769px) {
  .hide-desktop {
    display: none !important;
  }
}

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.animate-fadeIn { animation: fadeIn var(--transition-base); }
.animate-slideUp { animation: slideUp var(--transition-base); }

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}