:root {
  --primary-lake: #1B6CA8;
  --lake-deep: #0B3A5C;
  --sunset-orange: #F28705;
  --snow-white: #F8F9FA;
  --grass-green: #7CB342;
  --cloud-gray: #E3E9EF;
  --ink-blue: #172B3A;
  --ink-soft: #4A6578;
  --line-ice: #C5D3E0;
  --display-font: "DIN Condensed", "Oswald", "Arial Narrow", sans-serif;
  --body-font: "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --maxw: 1200px;
  --ease: 300ms ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--body-font);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--ink-blue);
  background: var(--snow-white);
  -webkit-font-smoothing: antialiased;
}

img, svg {
  max-width: 100%;
  display: block;
}

ul, ol {
  list-style: none;
}

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

a:hover {
  text-decoration: underline;
}

button {
  font: inherit;
  cursor: pointer;
}

h1, h2, h3, h4 {
  font-family: var(--display-font);
  font-weight: 700;
  line-height: 1.2;
  color: var(--ink-blue);
}

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

.container {
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: 24px;
}

.num {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

:focus-visible {
  outline: 2px solid var(--sunset-orange);
  outline-offset: 3px;
}

/* ===== 头部 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 500;
  background: var(--snow-white);
  transition: box-shadow 300ms ease;
}

.site-header.is-scrolled {
  box-shadow: 0 4px 18px rgba(11, 58, 92, 0.16);
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 12px;
  z-index: 1000;
  background: var(--lake-deep);
  color: var(--snow-white);
  padding: 10px 18px;
  font-weight: 600;
  font-size: .875rem;
  text-decoration: none;
}

.skip-link:focus {
  top: 12px;
  outline: none;
  box-shadow: 0 0 0 3px rgba(242, 135, 5, 0.7);
  text-decoration: none;
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--sunset-orange) 0%, var(--grass-green) 100%);
  z-index: 10;
  pointer-events: none;
}

.masthead {
  background: linear-gradient(120deg, var(--lake-deep) 0%, var(--primary-lake) 70%, var(--primary-lake) 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.masthead-inner {
  position: relative;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: padding 300ms ease;
}

.site-header.is-scrolled .masthead-inner {
  padding-top: 8px;
  padding-bottom: 8px;
}

.masthead-left,
.masthead-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  position: relative;
  display: inline-block;
  width: 34px;
  height: 34px;
  flex-shrink: 0;
  border: 1px solid rgba(255, 255, 255, 0.5);
  background: linear-gradient(135deg, transparent 42%, var(--sunset-orange) 42%, var(--sunset-orange) 58%, transparent 58%);
}

.brand-mark::after {
  content: "";
  position: absolute;
  width: 9px;
  height: 9px;
  right: -1px;
  bottom: -1px;
  background: var(--snow-white);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-title {
  font-family: var(--display-font);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--snow-white);
}

.brand-en {
  font-family: var(--display-font);
  font-size: .6rem;
  letter-spacing: .26em;
  color: rgba(255, 255, 255, 0.55);
  text-transform: uppercase;
}

.version-stamp {
  display: inline-block;
  font-family: var(--display-font);
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--snow-white);
  border: 1px solid rgba(255, 255, 255, 0.32);
  padding: 2px 10px;
  text-transform: uppercase;
}

.live-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .75rem;
  letter-spacing: .05em;
  color: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.22);
  padding: 3px 10px;
}

.live-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--grass-green);
  animation: live-pulse 2s ease-in-out infinite;
}

@keyframes live-pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.35); opacity: .65; }
}

.masthead-search {
  position: relative;
  display: flex;
  align-items: center;
}

.masthead-search-icon {
  position: absolute;
  left: 10px;
  color: rgba(255, 255, 255, 0.6);
  pointer-events: none;
  font-size: 1rem;
}

.masthead-search-input {
  width: 200px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 0;
  background: rgba(255, 255, 255, 0.12);
  color: var(--snow-white);
  font-family: var(--body-font);
  font-size: .875rem;
  padding: 8px 10px 8px 32px;
  transition: width 300ms ease, background 300ms ease, border-color 300ms ease;
}

.masthead-search-input::placeholder {
  color: rgba(255, 255, 255, 0.5);
}

.masthead-search-input:focus {
  width: 240px;
  outline: none;
  background: rgba(255, 255, 255, 0.2);
  border-color: var(--sunset-orange);
}

.search-panel {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 240px;
  background: var(--snow-white);
  border: 1px solid var(--line-ice);
  box-shadow: 0 10px 30px rgba(11, 58, 92, 0.16);
  z-index: 300;
  padding: 4px;
}

.search-panel[hidden] {
  display: none;
}

.search-panel a.search-result-link {
  display: block;
  padding: 8px 12px;
  font-size: .875rem;
  color: var(--ink-blue);
  font-weight: 500;
}

.search-panel a.search-result-link:hover {
  background: var(--cloud-gray);
  color: var(--primary-lake);
  text-decoration: none;
}

.search-empty {
  display: block;
  padding: 10px 12px;
  font-size: .875rem;
  color: var(--ink-soft);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 42px;
  height: 36px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.35);
  padding: 6px;
}

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--snow-white);
  transition: transform 300ms ease, opacity 300ms ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-nav {
  background: var(--snow-white);
  border-bottom: 1px solid var(--line-ice);
}

.nav-list {
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: 24px;
  display: flex;
  align-items: center;
  gap: 32px;
  min-height: 48px;
}

.nav-link {
  display: inline-block;
  font-family: var(--display-font);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: .05em;
  color: var(--ink-blue);
  padding: 4px 2px;
  position: relative;
  text-transform: uppercase;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: var(--sunset-orange);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 300ms ease;
}

.nav-link:hover {
  text-decoration: none;
  color: var(--primary-lake);
}

.nav-link:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

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

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--lake-deep);
  color: rgba(255, 255, 255, 0.75);
}

.footer-main {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 60px 24px 48px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.2fr 1.4fr;
  gap: 40px;
}

.footer-col {
  min-width: 0;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  text-decoration: none;
}

.footer-logo:hover {
  text-decoration: none;
}

.footer-brand-name {
  font-family: var(--display-font);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--snow-white);
}

.footer-trust {
  font-size: .875rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.6);
  max-width: 360px;
  margin-bottom: 16px;
}

.footer-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: .8rem;
  color: rgba(255, 255, 255, 0.68);
  border: 1px solid rgba(255, 255, 255, 0.16);
  padding: 4px 10px;
}

.footer-heading {
  font-family: var(--display-font);
  font-size: .85rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--sunset-orange);
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: .875rem;
  color: rgba(255, 255, 255, 0.72);
  transition: color 300ms ease;
}

.footer-links a:hover {
  color: var(--snow-white);
  text-decoration: none;
}

.footer-contact li {
  font-size: .875rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
  margin-bottom: 10px;
}

.footer-slug {
  display: inline-block;
  font-size: .72rem;
  letter-spacing: .1em;
  color: rgba(255, 255, 255, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 2px 8px;
  margin-top: 12px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 18px 24px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  font-size: .78rem;
  color: rgba(255, 255, 255, 0.5);
}

[data-year] {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.85);
}

/* ===== 页面共用骨架 ===== */
.page-header {
  background: linear-gradient(180deg, var(--cloud-gray) 0%, var(--snow-white) 100%);
  border-bottom: 1px solid var(--line-ice);
  padding: 56px 0 36px;
  margin-bottom: 48px;
}

.page-title {
  font-family: var(--display-font);
  font-size: clamp(2.2rem, 5vw, 4rem);
  letter-spacing: .04em;
  text-transform: uppercase;
  line-height: 1;
  color: var(--lake-deep);
}

.page-lead {
  margin-top: 14px;
  max-width: 680px;
  color: var(--ink-soft);
  font-size: 1.05rem;
  line-height: 1.8;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: .875rem;
  color: var(--ink-soft);
}

.breadcrumbs a {
  color: var(--primary-lake);
}

.breadcrumbs .sep {
  color: var(--line-ice);
}

.breadcrumbs [aria-current="page"] {
  color: var(--ink-soft);
  font-weight: 600;
}

.section {
  padding: 64px 0;
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 18px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--line-ice);
  padding-bottom: 14px;
}

.section-index {
  font-family: var(--display-font);
  font-size: clamp(2.5rem, 4vw, 3.8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--line-ice);
  min-width: 72px;
}

.section-title {
  font-family: var(--display-font);
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  text-transform: uppercase;
  letter-spacing: .03em;
  color: var(--ink-blue);
}

.text-lead {
  font-size: 1.15rem;
  color: var(--ink-soft);
  line-height: 1.8;
}

.divider {
  border: none;
  border-top: 1px solid var(--line-ice);
  margin: 40px 0;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--body-font);
  font-size: .9rem;
  font-weight: 600;
  line-height: 1;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 0;
  text-decoration: none;
  transition: background 300ms ease, color 300ms ease, border-color 300ms ease, transform 300ms ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

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

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

.btn-ghost {
  background: transparent;
  border-color: var(--line-ice);
  color: var(--primary-lake);
}

.btn-ghost:hover {
  background: rgba(27, 108, 168, 0.06);
  border-color: var(--primary-lake);
  color: var(--primary-lake);
}

.btn-orange {
  background: var(--sunset-orange);
  border-color: var(--sunset-orange);
  color: var(--snow-white);
}

.btn-orange:hover {
  background: #d97a04;
  border-color: #d97a04;
  color: var(--snow-white);
}

/* ===== 徽标 ===== */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  padding: 3px 10px;
  border: 1px solid;
  text-transform: uppercase;
}

.badge-lake {
  color: var(--primary-lake);
  border-color: var(--line-ice);
  background: rgba(27, 108, 168, 0.06);
}

.badge-sunset {
  color: var(--sunset-orange);
  border-color: rgba(242, 135, 5, 0.4);
  background: rgba(242, 135, 5, 0.08);
}

.badge-live {
  color: var(--grass-green);
  border-color: rgba(124, 179, 66, 0.4);
  background: rgba(124, 179, 66, 0.1);
}

/* ===== 栅格与卡片 ===== */
.grid {
  display: grid;
  gap: 20px;
}

.grid-cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-cols-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  background: var(--snow-white);
  border: 1px solid var(--line-ice);
  border-radius: 0;
  transition: transform 300ms ease, box-shadow 300ms ease;
}

.card-pad {
  padding: 24px;
}

.card-hover:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 28px rgba(11, 58, 92, 0.12);
}

/* ===== 图片容器 ===== */
.image-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(150deg, var(--cloud-gray), var(--snow-white));
  border: 1px solid var(--line-ice);
}

.image-frame::before {
  content: "";
  display: block;
  padding-top: 56.25%;
}

.image-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-frame-ratio-4x3::before {
  padding-top: 75%;
}

.image-frame-ratio-1x1::before {
  padding-top: 100%;
}

.image-frame-ratio-tall::before {
  padding-top: 140%;
}

/* ===== 响应式 ===== */
@media (max-width: 992px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .grid-cols-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 768px) {
  .masthead-inner {
    padding: 10px 16px;
    gap: 10px;
  }

  .version-stamp {
    display: none;
  }

  .live-badge {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .masthead-search-input {
    width: 150px;
  }

  .masthead-search-input:focus {
    width: 170px;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    box-shadow: 0 12px 28px rgba(11, 58, 92, 0.2);
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding-inline: 0;
  }

  .nav-link {
    display: block;
    padding: 14px 24px;
    border-bottom: 1px solid var(--line-ice);
  }

  .nav-link::after {
    display: none;
  }

  .nav-link[aria-current="page"] {
    background: rgba(27, 108, 168, 0.06);
  }

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

  .section {
    padding: 48px 0;
  }

  .section-head {
    gap: 12px;
  }
}

@media (max-width: 480px) {
  .masthead-inner {
    padding: 8px 12px;
    gap: 8px;
  }

  .brand {
    gap: 8px;
  }

  .brand-mark {
    width: 28px;
    height: 28px;
  }

  .brand-title {
    font-size: 1.05rem;
  }

  .brand-en {
    display: none;
  }

  .nav-toggle {
    width: 36px;
    height: 32px;
  }

  .masthead-search-input {
    width: 104px;
    font-size: .78rem;
    padding: 6px 6px 6px 26px;
  }

  .masthead-search-input:focus {
    width: 120px;
  }

  .masthead-search-icon {
    left: 8px;
    font-size: .85rem;
  }

  .search-panel {
    min-width: 200px;
  }

  .footer-main {
    padding: 40px 16px 32px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    justify-content: center;
    text-align: center;
  }

  .page-header {
    padding: 40px 0 28px;
    margin-bottom: 36px;
  }
}

/* ===== 无障碍动效 ===== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .live-dot {
    animation: none;
  }
}