/* ==========================================================================
   base
   ========================================================================== */

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  color: #2c3e50;
  background-color: #f5f6f8;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: #e67e22;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #c96a1a;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.4;
  color: #2c3e50;
}

p {
  margin-bottom: 1em;
}

time {
  color: #7f8c8d;
  font-size: 0.875rem;
}

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

/* ==========================================================================
   layout
   ========================================================================== */

.site-header {
  background-color: #2c3e50;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-shrink: 0;
}

.brand-name {
  font-size: 1.375rem;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0.5px;
}

.brand-tagline {
  font-size: 0.8125rem;
  color: #bdc3c7;
  display: none;
}

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

.site-nav .nav-list a {
  display: block;
  padding: 8px 16px;
  color: #ecf0f1;
  font-size: 0.9375rem;
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.site-nav .nav-list a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
}

.site-nav .nav-list a.is-current {
  color: #ffffff;
  background-color: rgba(230, 126, 34, 0.85);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle-icon {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #ffffff;
  position: relative;
  transition: background-color 0.2s ease;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 24px;
  height: 2px;
  background-color: #ffffff;
  transition: transform 0.2s ease;
}

.nav-toggle-icon::before {
  top: -7px;
}

.nav-toggle-icon::after {
  top: 7px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  transform: rotate(45deg);
  top: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  transform: rotate(-45deg);
  top: 0;
}

.site-main {
  flex: 1 0 auto;
}

.inner-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px 56px;
}

.site-footer {
  background-color: #2c3e50;
  color: #bdc3c7;
  flex-shrink: 0;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px 24px;
}

.footer-brand {
  margin-bottom: 32px;
}

.footer-slogan {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.footer-desc {
  font-size: 0.9375rem;
  color: #95a5a6;
  max-width: 560px;
  line-height: 1.7;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 32px;
}

.footer-title {
  font-size: 1rem;
  color: #ffffff;
  margin-bottom: 12px;
  font-weight: 600;
}

.footer-links ul li {
  margin-bottom: 8px;
}

.footer-links ul a {
  color: #bdc3c7;
  font-size: 0.875rem;
  transition: color 0.2s ease;
}

.footer-links ul a:hover {
  color: #e67e22;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 16px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8125rem;
  color: #95a5a6;
  margin-bottom: 0;
}

/* ==========================================================================
   components
   ========================================================================== */

/* --- 面包屑 --- */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.875rem;
  margin-bottom: 24px;
  color: #7f8c8d;
}

.breadcrumb a {
  color: #e67e22;
}

.breadcrumb a:hover {
  color: #c96a1a;
}

.breadcrumb-sep {
  color: #bdc3c7;
}

.breadcrumb-current {
  color: #2c3e50;
  font-weight: 500;
}

/* --- 页面标题区 --- */

.page-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid #e0e4e8;
}

.page-title {
  font-size: 2rem;
  font-weight: 700;
  color: #2c3e50;
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 1rem;
  color: #5d6d7e;
  line-height: 1.8;
  max-width: 720px;
  margin-bottom: 0;
}

/* --- 通用区块标题 --- */

.section-title {
  font-size: 1.375rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 20px;
  position: relative;
  padding-left: 14px;
}

.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  border-radius: 2px;
  background-color: #e67e22;
}

/* --- 按钮 --- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: 6px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  min-height: 44px;
}

.btn-primary {
  background-color: #e67e22;
  color: #ffffff;
}

.btn-primary:hover {
  background-color: #c96a1a;
  color: #ffffff;
}

.btn-secondary {
  background-color: transparent;
  color: #2c3e50;
  border-color: #2c3e50;
}

.btn-secondary:hover {
  background-color: #2c3e50;
  color: #ffffff;
}

.btn-outline {
  background-color: transparent;
  color: #e67e22;
  border-color: #e67e22;
}

.btn-outline:hover {
  background-color: #e67e22;
  color: #ffffff;
}

/* ==========================================================================
   pages
   ========================================================================== */

/* --- 首页：hero --- */

.home-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 56px;
}

.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  padding: 56px 0 48px;
}

.hero-media {
  order: 2;
}

.hero-figure {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.hero-figure img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.hero-content {
  order: 1;
}

.hero-title {
  font-size: 2.25rem;
  font-weight: 700;
  color: #2c3e50;
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-lead {
  font-size: 1.0625rem;
  color: #5d6d7e;
  line-height: 1.8;
  margin-bottom: 24px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* --- 首页：频道导航带 --- */

.channel-nav {
  margin-bottom: 48px;
}

.channel-tags {
  display: flex;
  gap: 12px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: thin;
  scrollbar-color: #e67e22 #ecf0f1;
}

.channel-tags::-webkit-scrollbar {
  height: 6px;
}

.channel-tags::-webkit-scrollbar-thumb {
  background-color: #e67e22;
  border-radius: 3px;
}

.channel-tags::-webkit-scrollbar-track {
  background-color: #ecf0f1;
}

.channel-tag {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background-color: #ecf0f1;
  color: #2c3e50;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 20px;
  transition: background-color 0.2s ease, color 0.2s ease;
  min-height: 40px;
}

.channel-tag:hover {
  background-color: #e67e22;
  color: #ffffff;
}

/* --- 首页：最新资讯列表 --- */

.latest-list {
  margin-bottom: 48px;
}

.news-items {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.news-item {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 20px;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 16px;
  border: 1px solid #e0e4e8;
  transition: box-shadow 0.2s ease;
}

.news-item:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.news-thumb img {
  width: 100%;
  height: 120px;
  object-fit: cover;
  border-radius: 6px;
}

.news-body {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.news-body h3 {
  font-size: 1.0625rem;
  margin-bottom: 8px;
}

.news-body h3 a {
  color: #2c3e50;
}

.news-body h3 a:hover {
  color: #e67e22;
}

.news-excerpt {
  font-size: 0.9375rem;
  color: #5d6d7e;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* --- 首页：专题推荐 --- */

.topic-cards {
  margin-bottom: 48px;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.topic-card {
  background-color: #ffffff;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid #e0e4e8;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

.topic-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.topic-card h3 {
  font-size: 1.125rem;
  padding: 16px 20px 4px;
}

.topic-card h3 a {
  color: #2c3e50;
}

.topic-card h3 a:hover {
  color: #e67e22;
}

.topic-card p {
  font-size: 0.9375rem;
  color: #5d6d7e;
  padding: 0 20px 20px;
  margin-bottom: 0;
}

/* --- 首页：信息来源与反馈 --- */

.info-feedback {
  background-color: #ecf0f1;
  border-radius: 8px;
  padding: 32px;
  margin-bottom: 24px;
}

.info-text {
  font-size: 0.9375rem;
  color: #5d6d7e;
  line-height: 1.8;
  margin-bottom: 16px;
  max-width: 720px;
}

/* --- 频道分类页 --- */

.channel-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.channel-card {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 20px;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 20px;
  border: 1px solid #e0e4e8;
  transition: box-shadow 0.2s ease;
}

.channel-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.channel-media img {
  width: 100%;
  height: 96px;
  object-fit: cover;
  border-radius: 6px;
}

.channel-content {
  display: flex;
  flex-direction: column;
}

.channel-name {
  font-size: 1.125rem;
  margin-bottom: 6px;
}

.channel-desc {
  font-size: 0.875rem;
  color: #5d6d7e;
  margin-bottom: 8px;
  flex: 1;
}

.channel-link {
  font-size: 0.875rem;
  font-weight: 500;
}

.channel-notes {
  background-color: #ecf0f1;
  border-radius: 8px;
  padding: 24px;
}

.notes-intro {
  font-size: 0.9375rem;
  color: #5d6d7e;
  margin-bottom: 16px;
}

.notes-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.notes-links a {
  font-size: 0.9375rem;
  font-weight: 500;
}

/* --- 内容专题页 --- */

.topic-grid .topic-card {
  display: flex;
  flex-direction: column;
}

.topic-media img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.topic-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 16px 20px 20px;
}

.topic-title {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.topic-title a {
  color: #2c3e50;
}

.topic-title a:hover {
  color: #e67e22;
}

.topic-summary {
  font-size: 0.9375rem;
  color: #5d6d7e;
  margin-bottom: 12px;
  flex: 1;
}

.topic-link {
  font-size: 0.875rem;
  font-weight: 500;
}

.topic-summary-section {
  background-color: #ecf0f1;
  border-radius: 8px;
  padding: 24px;
  margin-top: 40px;
}

.summary-content p {
  font-size: 0.9375rem;
  color: #5d6d7e;
  line-height: 1.8;
  margin-bottom: 12px;
}

.summary-content p:last-child {
  margin-bottom: 0;
}

/* --- 阅读帮助页 --- */

.guide-section {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 24px;
  border: 1px solid #e0e4e8;
}

.guide-section h2 {
  font-size: 1.25rem;
  color: #2c3e50;
  margin-bottom: 12px;
}

.guide-section p {
  font-size: 0.9375rem;
  color: #5d6d7e;
  line-height: 1.8;
}

.guide-figure {
  margin: 16px 0;
}

.guide-figure img {
  width: 100%;
  max-height: 240px;
  object-fit: cover;
  border-radius: 6px;
}

.guide-figure figcaption {
  font-size: 0.8125rem;
  color: #7f8c8d;
  text-align: center;
  padding: 8px 0 0;
}

/* --- 时间线页 --- */

.timeline-groups {
  margin-bottom: 40px;
}

.timeline-title {
  font-size: 1.375rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 12px;
  position: relative;
  padding-left: 14px;
}

.timeline-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  border-radius: 2px;
  background-color: #e67e22;
}

.timeline-intro {
  font-size: 0.9375rem;
  color: #5d6d7e;
  margin-bottom: 32px;
}

.timeline-group {
  position: relative;
  padding-left: 32px;
  margin-bottom: 32px;
  border-left: 2px solid #e0e4e8;
}

.timeline-month {
  font-size: 1.0625rem;
  font-weight: 600;
  color: #2c3e50;
  margin-bottom: 16px;
  position: relative;
}

.timeline-month::before {
  content: "";
  position: absolute;
  left: -37px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: #e67e22;
  border: 2px solid #ffffff;
  box-shadow: 0 0 0 2px #e67e22;
}

.timeline-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.timeline-item {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 16px 20px;
  border: 1px solid #e0e4e8;
}

.timeline-item time {
  display: block;
  font-size: 0.8125rem;
  color: #7f8c8d;
  margin-bottom: 4px;
}

.timeline-item h4 {
  font-size: 1rem;
  color: #2c3e50;
  margin-bottom: 6px;
}

.timeline-item p {
  font-size: 0.875rem;
  color: #5d6d7e;
  margin-bottom: 0;
}

.event-summary {
  background-color: #ecf0f1;
  border-radius: 8px;
  padding: 24px;
}

.summary-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 16px;
}

.summary-content p {
  font-size: 0.9375rem;
  color: #5d6d7e;
  line-height: 1.8;
  margin-bottom: 12px;
}

.summary-content a {
  font-weight: 500;
}

.timeline-figure {
  margin-top: 16px;
}

.timeline-figure img {
  width: 100%;
  max-height: 240px;
  object-fit: cover;
  border-radius: 6px;
}

.timeline-figure figcaption {
  font-size: 0.8125rem;
  color: #7f8c8d;
  text-align: center;
  padding: 8px 0 0;
}

/* --- 404 页 --- */

.error-main {
  flex: 1 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
}

.error-section {
  text-align: center;
  max-width: 560px;
  width: 100%;
}

.error-code {
  font-size: 6rem;
  font-weight: 700;
  color: #e67e22;
  line-height: 1.2;
  margin-bottom: 8px;
}

.error-title {
  font-size: 1.75rem;
  color: #2c3e50;
  margin-bottom: 16px;
}

.error-desc {
  font-size: 1rem;
  color: #5d6d7e;
  margin-bottom: 8px;
}

.error-tip {
  font-size: 0.9375rem;
  color: #7f8c8d;
  margin-bottom: 24px;
}

.error-back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  background-color: #e67e22;
  color: #ffffff;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: 6px;
  min-height: 44px;
  transition: background-color 0.2s ease;
}

.error-back:hover {
  background-color: #c96a1a;
  color: #ffffff;
}

/* ==========================================================================
   responsive
   ========================================================================== */

@media (min-width: 769px) {
  .brand-tagline {
    display: inline;
  }
}

@media (max-width: 768px) {
  .header-inner {
    min-height: 60px;
    padding: 0 16px;
  }

  .brand-name {
    font-size: 1.25rem;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background-color: #2c3e50;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    padding: 8px 16px 16px;
    gap: 4px;
  }

  .site-nav .nav-list.is-open {
    display: flex;
  }

  .site-nav .nav-list a {
    padding: 12px 16px;
    font-size: 1rem;
    border-radius: 6px;
  }

  .home-main,
  .inner-main {
    padding: 24px 16px 40px;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 0 32px;
  }

  .hero-media {
    order: 1;
  }

  .hero-content {
    order: 2;
  }

  .hero-figure img {
    height: 200px;
  }

  .hero-title {
    font-size: 1.625rem;
  }

  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .news-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .news-thumb img {
    height: 160px;
  }

  .topic-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .channel-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .channel-card {
    grid-template-columns: 100px 1fr;
    gap: 16px;
    padding: 16px;
  }

  .channel-media img {
    height: 80px;
  }

  .page-title {
    font-size: 1.5rem;
  }

  .footer-links {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .footer-inner {
    padding: 32px 16px 16px;
  }

  .info-feedback {
    padding: 20px;
  }

  .guide-section {
    padding: 20px;
  }

  .timeline-group {
    padding-left: 24px;
  }

  .timeline-month::before {
    left: -29px;
  }

  .error-code {
    font-size: 4.5rem;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .hero {
    gap: 32px;
    padding: 40px 0;
  }

  .hero-title {
    font-size: 1.875rem;
  }

  .hero-figure img {
    height: 260px;
  }

  .news-item {
    grid-template-columns: 140px 1fr;
  }

  .channel-card {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .channel-media img {
    height: 120px;
  }
}

@media (max-width: 480px) {
  .brand-tagline {
    display: none;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-lead {
    font-size: 1rem;
  }

  .news-thumb img {
    height: 140px;
  }

  .channel-card {
    grid-template-columns: 1fr;
  }

  .channel-media img {
    height: 140px;
  }

  .topic-card img,
  .topic-media img {
    height: 150px;
  }

  .timeline-group {
    padding-left: 20px;
  }

  .timeline-month::before {
    left: -25px;
  }

  .footer-links {
    gap: 20px;
  }
}