/* ========== CSS 重置与变量 ========== */
:root {
  --red: #E63946;
  --red-dark: #B51324;
  --blue: #1D3557;
  --blue-light: #457B9D;
  --gold: #C9A227;
  --blue-black: #0B1D2E;
  --glass: rgba(16,42,60,0.72);
  --white: #F1F4F8;
  --steel: #A7B6C5;
  --light: #F5F5F5;
  --font-heading: 'Anton', 'Arial Narrow', Arial, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-data: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --space-7: 96px;
  --container-max: 1440px;
  --header-height: 72px;
  --radius: 2px;
  --transition: 0.2s ease;
  --focus-ring: 0 0 0 2px var(--gold);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--space-3));
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  background-color: var(--blue-black);
  color: var(--white);
  min-height: 100vh;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: var(--blue-light);
  text-decoration: none;
  transition: color var(--transition);
}

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

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.15;
  color: var(--white);
  letter-spacing: 0.01em;
}

h1 {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 800;
}

h2 {
  font-size: clamp(2rem, 4vw, 2.75rem);
}

h3 {
  font-size: 1.5rem;
}

h4 {
  font-size: 1.25rem;
}

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

::selection {
  background: var(--red);
  color: #fff;
}

/* ========== 通用容器与布局 ========== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-3);
}

.site-main {
  min-height: 70vh;
  padding-top: calc(var(--header-height) + var(--space-4));
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 9999;
  background: var(--blue-light);
  color: #fff;
  padding: 8px 16px;
  border-radius: 2px;
  font-weight: 600;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 16px;
}

/* ========== 按钮 ========== */
.btn {
  display: inline-block;
  padding: 8px 20px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.6;
  text-align: center;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color var(--transition), border-color var(--transition), color var(--transition), transform var(--transition);
  border: 2px solid transparent;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
}

.btn-primary:hover {
  background: var(--red-dark);
  border-color: var(--red-dark);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  border-color: var(--blue-light);
  color: var(--blue-light);
}

.btn-secondary:hover {
  border-color: var(--red);
  color: var(--red);
}

/* ========== 头部导航 ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
  pointer-events: none;
}

.site-header .container {
  pointer-events: auto;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.02em;
}

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

.brand-mark {
  width: 10px;
  height: 28px;
  background: var(--red);
  display: inline-block;
  transform: skewX(-15deg);
  border-radius: 1px;
  box-shadow: 1px 1px 0 var(--gold);
}

.brand-text {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  letter-spacing: 0.04em;
}

.brand-cn {
  color: var(--steel);
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 400;
  margin-left: 6px;
  letter-spacing: 0.12em;
}

/* 悬浮胶囊导航 */
.nav-capsule {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(69,123,157,0.4);
  border-radius: 999px;
  padding: 6px 6px 6px 24px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.35);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-menu a {
  display: block;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--steel);
  transition: background-color var(--transition), color var(--transition);
}

.nav-menu a:hover {
  color: var(--white);
  background: rgba(69,123,157,0.2);
}

.nav-menu a[aria-current="page"] {
  background: var(--red);
  color: #fff;
}

.nav-cta {
  margin-left: 8px;
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  background: var(--glass);
  border: 1px solid rgba(69,123,157,0.4);
  border-radius: 999px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.nav-toggle .bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--white);
  border-radius: 1px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

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

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

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

/* ========== 页脚 ========== */
.site-footer {
  background: var(--blue-black);
  border-top: 1px solid rgba(69,123,157,0.3);
  margin-top: var(--space-7);
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--red) 0%, var(--red) 30%, var(--blue-light) 30%, var(--blue-light) 70%, var(--gold) 70%, var(--gold) 100%);
}

.site-footer .footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-5);
  padding-top: var(--space-6);
  padding-bottom: var(--space-5);
}

.footer-brand-mark {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  color: var(--light);
  letter-spacing: 0.06em;
  margin-bottom: var(--space-2);
}

.footer-tagline {
  color: var(--steel);
  font-size: 14px;
  margin-bottom: var(--space-3);
  line-height: 1.8;
}

.footer-service {
  color: var(--steel);
  font-size: 13px;
  line-height: 1.8;
  max-width: 36em;
  background: rgba(29,53,87,0.5);
  padding: var(--space-2);
  border-left: 2px solid var(--blue-light);
}

.footer-heading {
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: var(--space-3);
}

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  color: var(--steel);
  font-size: 14px;
}

.footer-links a:hover {
  color: var(--white);
}

.footer-meta {
  border-top: 1px solid rgba(69,123,157,0.25);
  padding: var(--space-3) 0;
}

.meta-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2);
  font-size: 13px;
  color: var(--steel);
}

.meta-inner p {
  margin: 0;
}

.meta-copyright {
  font-family: var(--font-data);
}

/* ========== 面包屑 ========== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  padding: var(--space-3) 0;
  font-size: 13px;
  color: var(--steel);
}

.breadcrumb a {
  color: var(--blue-light);
}

.breadcrumb a:hover {
  color: var(--red);
}

.breadcrumb .sep {
  color: var(--gold);
}

.breadcrumb [aria-current="page"] {
  color: var(--white);
}

/* ========== 正文容器 ========== */
.content {
  max-width: 880px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-3);
}

.content p {
  margin-bottom: var(--space-3);
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.content ul,
.content ol {
  margin: 0 auto var(--space-3) auto;
  padding-left: var(--space-3);
  color: var(--steel);
}

.content li {
  margin-bottom: 8px;
}

/* ========== 左右分屏系统 ========== */
.split-layout {
  display: grid;
  grid-template-columns: 4fr 8fr;
  gap: var(--space-4);
  align-items: stretch;
}

.split-panel {
  background: var(--red);
  padding: var(--space-5);
  position: relative;
  overflow: hidden;
  border-radius: 4px;
}

.split-panel::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 100%;
  height: 100%;
  background-image: repeating-linear-gradient(45deg, rgba(255,255,255,0.04) 0px, rgba(255,255,255,0.04) 2px, transparent 2px, transparent 12px);
  pointer-events: none;
}

.content-panel {
  background: var(--blue);
  padding: var(--space-5);
  border-radius: 4px;
  position: relative;
}

/* ========== 背景纹理 ========== */
.bg-texture {
  background-image: repeating-linear-gradient(45deg, rgba(69,123,157,0.08) 0px, rgba(69,123,157,0.08) 2px, transparent 2px, transparent 14px);
}

/* ========== 编号章节标题 ========== */
.number-title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.number-title .num {
  font-family: var(--font-data);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 0.1em;
}

.gold-accent {
  color: var(--gold);
}

/* ========== 数据滚动条 ========== */
.data-ticker {
  overflow: hidden;
  background: rgba(11,29,46,0.6);
  border-top: 1px solid var(--blue-light);
  border-bottom: 1px solid var(--blue-light);
  padding: 12px 0;
  margin: var(--space-4) 0;
}

.ticker-track {
  display: flex;
  gap: 48px;
  white-space: nowrap;
  animation: ticker-scroll 40s linear infinite;
  width: max-content;
  align-items: center;
}

.data-ticker[data-paused="true"] .ticker-track {
  animation-play-state: paused;
}

[data-ticker] .ticker-track {
  animation-name: ticker-scroll;
}

.ticker-item {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-data);
  font-size: 13px;
  color: var(--blue-light);
}

.ticker-item .gold {
  color: var(--gold);
  font-weight: 700;
}

.ticker-item .red {
  color: var(--red);
  font-weight: 700;
}

@keyframes ticker-scroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ========== 图片容器（页面阶段使用） ========== */
.media-frame {
  position: relative;
  border-radius: 3px;
  overflow: hidden;
  background: var(--blue);
  border: 1px solid var(--blue-light);
  aspect-ratio: 16 / 9;
}

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

.media-frame--wide {
  aspect-ratio: 21 / 9;
}

.media-frame--portrait {
  aspect-ratio: 4 / 5;
}

/* ========== 卡片 ========== */
.card {
  background: var(--glass);
  border: 1px solid rgba(69,123,157,0.4);
  border-radius: 4px;
  padding: var(--space-4);
  transition: transform 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--red);
}

/* ========== 阅读进度条 ========== */
.progress-track {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  z-index: 999;
  background: transparent;
  pointer-events: none;
}

#progress-bar {
  display: block;
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--red), var(--blue-light), var(--gold));
  border-radius: 0 2px 2px 0;
}

/* ========== 工具类 ========== */
.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;
}

/* ========== 响应式 ========== */
@media (min-width: 1200px) and (max-width: 1399px) {
  .nav-capsule {
    padding-left: 12px;
  }

  .nav-menu a {
    padding: 6px 10px;
    font-size: 13px;
  }

  .nav-cta {
    margin-left: 4px;
  }
}

@media (max-width: 1199px) {
  .split-layout {
    grid-template-columns: 1fr;
  }

  .nav-cta {
    display: none;
  }
}

@media (max-width: 960px) {
  .site-header {
    height: auto;
    padding: var(--space-2) 0;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-capsule {
    position: fixed;
    top: calc(var(--header-height) + 8px);
    left: var(--space-3);
    right: var(--space-3);
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    border-radius: 8px;
    padding: var(--space-3);
    background: rgba(11,29,46,0.96);
    border-color: rgba(69,123,157,0.6);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
    box-shadow: 0 16px 48px rgba(0,0,0,0.5);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    max-height: calc(100vh - 100px);
    overflow-y: auto;
    display: flex;
    align-items: flex-start;
  }

  .nav-capsule[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-menu {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
  }

  .nav-menu a {
    padding: 12px 16px;
    border-radius: 4px;
    font-size: 16px;
  }

  .nav-menu a[aria-current="page"] {
    background: var(--red);
  }

  .nav-cta {
    display: block;
    text-align: center;
    margin-left: 0;
    margin-top: 4px;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

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

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

  .brand-cn {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .meta-inner {
    flex-direction: column;
    gap: var(--space-1);
  }

  .split-panel,
  .content-panel {
    padding: var(--space-3);
  }

  .footer-tagline {
    font-size: 13px;
  }

  .site-main {
    padding-top: calc(var(--header-height) + 20px);
  }
}

@media (max-width: 480px) {
  .nav-cta {
    font-size: 13px;
    padding: 8px 14px;
  }

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

  .nav-capsule {
    left: var(--space-2);
    right: var(--space-2);
  }

  .card {
    padding: var(--space-3);
  }
}

/* 高度适配 */
@media (max-height: 600px) and (max-width: 960px) {
  .nav-capsule {
    max-height: calc(100vh - 80px);
    overflow-y: auto;
  }
}

/* ========== 无障碍 ========== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .ticker-track {
    animation: none;
  }

  html {
    scroll-behavior: auto;
  }
}