/* ========================================
   Qoder Documentation - Style System
   ======================================== */

/* --- CSS Variables / Theme --- */
:root {
  /* Colors - Light */
  --color-bg: #ffffff;
  --color-bg-secondary: #f8f9fb;
  --color-bg-tertiary: #f0f2f5;
  --color-surface: #ffffff;
  --color-border: #e2e5ea;
  --color-border-hover: #c4c9d1;
  --color-text-primary: #1a1d23;
  --color-text-secondary: #5c6370;
  --color-text-tertiary: #8b919a;
  --color-accent: #6366f1;
  --color-accent-light: #eef2ff;
  --color-accent-hover: #4f46e5;
  --color-badge-common: #10b981;
  --color-badge-common-bg: #ecfdf5;
  --color-badge-advanced: #6b7280;
  --color-badge-advanced-bg: #f3f4f6;
  --color-code-bg: #f4f5f7;
  --color-overlay: rgba(0, 0, 0, 0.5);
  --color-nav-active: #6366f1;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-size-xs: 12px;
  --font-size-sm: 13px;
  --font-size-base: 15px;
  --font-size-lg: 18px;
  --font-size-xl: 22px;
  --font-size-2xl: 28px;
  --font-size-3xl: 36px;

  /* Layout */
  --sidebar-width: 260px;
  --toc-width: 200px;
  --header-height: 60px;
  --content-max-width: 780px;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

/* --- Dark Theme --- */
[data-theme="dark"] {
  --color-bg: #0f1117;
  --color-bg-secondary: #161922;
  --color-bg-tertiary: #1e2230;
  --color-surface: #1a1e2a;
  --color-border: #2a2f3e;
  --color-border-hover: #3d4458;
  --color-text-primary: #e8eaed;
  --color-text-secondary: #9ca3b0;
  --color-text-tertiary: #6b7280;
  --color-accent: #818cf8;
  --color-accent-light: #1e1b4b;
  --color-accent-hover: #a5b4fc;
  --color-badge-common: #34d399;
  --color-badge-common-bg: #064e3b;
  --color-badge-advanced: #9ca3af;
  --color-badge-advanced-bg: #1f2937;
  --color-code-bg: #1e2230;
  --color-overlay: rgba(0, 0, 0, 0.7);
  --color-nav-active: #818cf8;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--space-lg));
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: 1.7;
  color: var(--color-text-primary);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

/* --- Header / Top Nav --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  padding: 0 var(--space-xl);
  z-index: 100;
  backdrop-filter: blur(8px);
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
}

.header__logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  white-space: nowrap;
}

.header__logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 14px;
}

.header__tabs {
  display: flex;
  gap: var(--space-xs);
  margin-left: var(--space-2xl);
}

.header__tab {
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  background: none;
  font-family: inherit;
}

.header__tab:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
}

.header__tab.active {
  color: var(--color-accent);
  background: var(--color-accent-light);
  border-color: color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-left: auto;
}

.header__search {
  position: relative;
}

.header__search-input {
  width: 220px;
  padding: var(--space-sm) var(--space-md);
  padding-left: 36px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  font-family: inherit;
  outline: none;
  transition: all var(--transition-fast);
}

.header__search-input:focus {
  border-color: var(--color-accent);
  width: 280px;
}

.header__search-input::placeholder {
  color: var(--color-text-tertiary);
}

.header__search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-tertiary);
  width: 14px;
  height: 14px;
}

.header__theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.header__theme-toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text-primary);
}

.header__mobile-toggle {
  display: none;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* --- Layout --- */
.layout {
  display: flex;
  padding-top: var(--header-height);
  min-height: 100vh;
}

/* --- Sidebar --- */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  border-right: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  overflow-y: auto;
  padding: var(--space-lg) 0;
  z-index: 50;
  transition: transform var(--transition-normal);
}

.sidebar__section-label {
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
  margin-top: var(--space-md);
}

.sidebar__section-label:first-child {
  margin-top: 0;
}

.sidebar__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border-left: 2px solid transparent;
  text-decoration: none;
}

.sidebar__item:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
}

.sidebar__item.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  background: var(--color-accent-light);
}

.sidebar__badge {
  font-size: 10px;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: auto;
  white-space: nowrap;
}

.sidebar__badge--common {
  color: var(--color-badge-common);
  background: var(--color-badge-common-bg);
}

.sidebar__badge--advanced {
  color: var(--color-badge-advanced);
  background: var(--color-badge-advanced-bg);
}

/* --- Main Content --- */
.main {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: var(--space-2xl) var(--space-3xl);
  max-width: calc(var(--content-max-width) + var(--sidebar-width) + var(--toc-width) + var(--space-3xl) * 2);
}

.main__content {
  max-width: var(--content-max-width);
}

/* --- Section --- */
.section {
  display: none;
  animation: fadeIn 0.3s ease;
}

.section.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.section__hero {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
}

.section__hero-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--space-sm);
  line-height: 1.2;
}

.section__hero-desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
}

/* --- Category Label --- */
.category-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-lg);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
}

.category-label--common {
  color: var(--color-badge-common);
  background: var(--color-badge-common-bg);
}

.category-label--advanced {
  color: var(--color-badge-advanced);
  background: var(--color-badge-advanced-bg);
}

.category-label__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

/* --- Article Card --- */
.article {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
}

.article:last-child {
  border-bottom: none;
}

.article__title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
  scroll-margin-top: calc(var(--header-height) + var(--space-lg));
}

.article__desc {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
  line-height: 1.8;
}

.article__steps {
  list-style: none;
  counter-reset: step;
}

.article__steps li {
  counter-increment: step;
  position: relative;
  padding-left: var(--space-xl);
  margin-bottom: var(--space-md);
  color: var(--color-text-secondary);
}

.article__steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 2px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-size: var(--font-size-xs);
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* --- Code Block --- */
.code-block {
  position: relative;
  background: var(--color-code-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin: var(--space-md) 0;
  overflow-x: auto;
}

.code-block code {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  line-height: 1.6;
  color: var(--color-text-primary);
}

.code-block__copy {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-tertiary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  font-size: 12px;
}

.code-block__copy:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text-primary);
}

/* --- Screenshot / Image --- */
.screenshot {
  margin: var(--space-lg) 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.screenshot:hover {
  border-color: var(--color-border-hover);
}

.screenshot img {
  width: 100%;
  height: auto;
  display: block;
}

.screenshot__placeholder {
  width: 100%;
  height: 200px;
  background: var(--color-bg-tertiary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

.screenshot__placeholder-icon {
  width: 40px;
  height: 40px;
  opacity: 0.4;
}

/* --- Keyboard Shortcut --- */
kbd {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
}

/* --- Tip Box --- */
.tip {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-light);
  margin: var(--space-lg) 0;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.tip strong {
  color: var(--color-accent);
}

/* --- Collapsible (Advanced) --- */
.collapsible {
  margin-top: var(--space-lg);
}

.collapsible__toggle {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  cursor: pointer;
  width: 100%;
  text-align: left;
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.collapsible__toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text-primary);
}

.collapsible__toggle-icon {
  transition: transform var(--transition-fast);
  font-size: 12px;
}

.collapsible.open .collapsible__toggle-icon {
  transform: rotate(90deg);
}

.collapsible__content {
  display: none;
  padding-top: var(--space-lg);
}

.collapsible.open .collapsible__content {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* --- TOC (Right sidebar) --- */
.toc {
  position: fixed;
  top: calc(var(--header-height) + var(--space-2xl));
  right: var(--space-xl);
  width: var(--toc-width);
  max-height: calc(100vh - var(--header-height) - var(--space-3xl));
  overflow-y: auto;
}

.toc__title {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-md);
}

.toc__item {
  display: block;
  padding: var(--space-xs) 0;
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  transition: color var(--transition-fast);
  border-left: 2px solid transparent;
  padding-left: var(--space-md);
  text-decoration: none;
}

.toc__item:hover {
  color: var(--color-text-secondary);
}

.toc__item.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

/* --- Lightbox --- */
.lightbox {
  position: fixed;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.lightbox.active {
  opacity: 1;
  visibility: visible;
}

.lightbox__img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius-lg);
}

.lightbox__close {
  position: absolute;
  top: var(--space-xl);
  right: var(--space-xl);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: #fff;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* --- Search Results --- */
.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: var(--space-xs);
  max-height: 300px;
  overflow-y: auto;
  display: none;
  z-index: 200;
}

.search-results.active {
  display: block;
}

.search-results__item {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.search-results__item:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.search-results__item-tab {
  font-size: 10px;
  color: var(--color-text-tertiary);
  margin-left: var(--space-sm);
}

.search-results__empty {
  padding: var(--space-lg);
  text-align: center;
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

/* --- Responsive --- */
@media (max-width: 1200px) {
  .toc {
    display: none;
  }
}

@media (max-width: 900px) {
  .header__search-input {
    width: 160px;
  }

  .header__search-input:focus {
    width: 200px;
  }

  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main {
    margin-left: 0;
    padding: var(--space-xl) var(--space-lg);
  }

  .header__mobile-toggle {
    display: flex;
  }

  .header__tabs {
    margin-left: var(--space-lg);
  }
}

@media (max-width: 600px) {
  .header__tabs {
    display: none;
  }

  .header__search {
    display: none;
  }

  .section__hero-title {
    font-size: var(--font-size-2xl);
  }

  .main {
    padding: var(--space-lg) var(--space-md);
  }
}