/* ========================================
   Site CSS (assets/site.css)
   乐鱼赛事 LeYu Sports Video
   ======================================== */

/* --- CSS Variables --- */
:root {
  --color-primary: #1a2a6a;
  --color-accent: #ff6600;
  --color-accent-hover: #e65c00;
  --color-neutral-dark: #1a1a1a;
  --color-neutral-light: #f5f5f5;
  --color-white: #ffffff;
  --color-gray-medium: #888888;
  --color-gray-light: #cccccc;

  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  --font-size-h1: 3rem; /* 48px */
  --font-size-h2: 2.25rem; /* 36px */
  --font-size-h3: 1.5rem; /* 24px */
  --font-size-body: 1rem; /* 16px */
  --font-size-small: 0.875rem; /* 14px */

  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;

  --container-max-width: 1200px;
  --border-radius: 4px;
  --transition-base: 0.2s ease-in-out;
}

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

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

body {
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  line-height: 1.6;
  color: var(--color-neutral-dark);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul, ol {
  list-style: none;
}

/* --- Accessibility --- */
:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  z-index: 1000;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-accent);
  color: var(--color-white);
  font-weight: 700;
  transition: top 0.3s;
}

.skip-link:focus {
  top: 0;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-primary);
}

h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }

.mono {
  font-family: var(--font-mono);
  font-weight: 400;
}

.index-number {
  font-family: var(--font-mono);
  font-size: var(--font-size-h1);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}

/* --- Container & Grid --- */
.container {
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--spacing-md);
  padding-right: var(--spacing-md);
}

/* --- Header --- */
.site-header {
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-sm) 0;
  border-bottom: 3px solid var(--color-accent);
  position: relative;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.site-brand {
  display: flex;
  flex-direction: column;
}

.brand-link {
  display: flex;
  flex-direction: column;
  color: var(--color-white);
  text-decoration: none;
}

.brand-link:hover {
  color: var(--color-white);
}

.brand-text {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  text-transform: uppercase;
  line-height: 1.1;
}

.brand-sub {
  font-family: var(--font-body);
  font-size: var(--font-size-small);
  font-weight: 400;
  color: var(--color-gray-light);
  letter-spacing: 0.05em;
}

/* --- Navigation --- */
.site-nav {
  display: none;
  width: 100%;
  margin-top: var(--spacing-sm);
  border-top: 1px solid rgba(255,255,255,0.2);
  padding-top: var(--spacing-sm);
}

.site-nav[data-open] {
  display: block;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.nav-link {
  display: block;
  padding: var(--spacing-xs) 0;
  color: var(--color-white);
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: var(--font-size-body);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition-base), color var(--transition-base);
}

.nav-link:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.nav-link[aria-current="page"] {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  font-weight: 700;
}

/* Nav Toggle (Mobile) */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--color-white);
  border-radius: var(--border-radius);
  cursor: pointer;
  padding: var(--spacing-xs);
  gap: 4px;
}

.nav-toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* --- Footer --- */
.site-footer {
  background-color: var(--color-neutral-dark);
  color: var(--color-gray-light);
  padding: var(--spacing-xl) 0 var(--spacing-lg);
  border-top: 4px solid var(--color-accent);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.footer-brand {
  display: flex;
  flex-direction: column;
}

.footer-brand-text {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-white);
}

.footer-brand-sub {
  font-size: var(--font-size-small);
  color: var(--color-gray-medium);
}

.footer-info p {
  margin-bottom: var(--spacing-sm);
}

.footer-copyright {
  color: var(--color-white);
}

.footer-icp {
  color: var(--color-gray-light);
  font-size: var(--font-size-small);
}

.footer-contact a {
  color: var(--color-gray-light);
}

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

.footer-address {
  font-size: var(--font-size-small);
}

.footer-links {
  display: flex;
  gap: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-gray-medium);
}

.footer-link {
  color: var(--color-gray-light);
  font-size: var(--font-size-small);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-link:hover {
  color: var(--color-accent);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--font-size-body);
  border: 2px solid transparent;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: background-color var(--transition-base), color var(--transition-base), border-color var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-white);
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: var(--color-white);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

/* --- Card --- */
.card {
  background-color: var(--color-neutral-light);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  border: 1px solid var(--color-gray-light);
  transition: box-shadow var(--transition-base), border-color var(--transition-base);
}

.card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  border-color: var(--color-accent);
}

/* --- Legend (Map Legend Component) --- */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin: var(--spacing-md) 0;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-small);
  color: var(--color-gray-medium);
}

.legend-dot {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--color-primary);
  flex-shrink: 0;
}

.legend-dot[data-color="accent"] {
  background-color: var(--color-accent);
}

.legend-dot[data-color="primary"] {
  background-color: var(--color-primary);
}

/* --- Tag --- */
.tag {
  display: inline-block;
  padding: 2px var(--spacing-sm);
  font-family: var(--font-mono);
  font-size: var(--font-size-small);
  border: 1px solid var(--color-gray-light);
  border-radius: 2px;
  background-color: var(--color-white);
  color: var(--color-gray-medium);
}

/* --- Diagonal Cut Decoration --- */
.diagonal {
  clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
  padding-bottom: 15%;
}

/* --- Image Container Placeholder --- */
.image-container {
  background-color: var(--color-neutral-light);
  aspect-ratio: 16 / 9;
  border-radius: var(--border-radius);
  border: 1px dashed var(--color-gray-light);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gray-medium);
  font-size: var(--font-size-small);
}

/* --- Scroll Progress Bar --- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-primary));
  z-index: 9999;
  transition: width 0.1s linear;
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-lg);
  right: var(--spacing-lg);
  width: 48px;
  height: 48px;
  background-color: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base), background-color var(--transition-base);
}

.back-to-top[data-visible] {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-accent);
  color: var(--color-white);
}

/* --- Responsive --- */
@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  .site-nav {
    display: flex !important;
    width: auto;
    margin-top: 0;
    border-top: none;
    padding-top: 0;
  }

  .nav-list {
    flex-direction: row;
    gap: var(--spacing-lg);
  }

  .nav-link {
    padding: var(--spacing-sm) 0;
    font-size: var(--font-size-small);
  }

  .footer-inner {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
  }

  .footer-brand {
    flex-basis: 100%;
  }

  .footer-info {
    flex: 1;
  }
}

@media (min-width: 1024px) {
  .header-inner {
    flex-wrap: nowrap;
  }

  .site-nav {
    flex: 1;
    justify-content: flex-end;
  }

  .nav-link {
    font-size: var(--font-size-body);
  }

  .footer-brand {
    flex-basis: auto;
  }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .skip-link {
    transition: none;
  }
}