/* ====================================================
   华体中文官网 · /assets/site.css
   全站共用样式：变量、排版、头部、页脚、基础组件
   ==================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  --c-primary: #0B1F3A;
  --c-primary-2: #1A3A5C;
  --c-secondary: #FF5C35;
  --c-secondary-2: #FF8A65;
  --c-accent: #8A9BB2;
  --c-bg: #EAF0F6;
  --c-text: #0A1A2F;
  --c-text-on-dark: #FFFFFF;
  --c-link: #1A5FB4;
  --c-border: rgba(138, 155, 178, 0.35);
  --gradient-primary: linear-gradient(135deg, #0B1F3A 0%, #1A3A5C 100%);
  --gradient-accent: linear-gradient(45deg, #FF5C35 0%, #FF8A65 100%);
  --font-headline: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-latin: "Rajdhani", "Arial Narrow", sans-serif;
  --content-w: 1200px;
  --header-h: 72px;
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --shadow-sm: 0 2px 8px rgba(10, 26, 47, 0.07);
  --shadow-md: 0 12px 32px rgba(10, 26, 47, 0.12);
}

/* ---------- 2. 重置与基础 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
  background: var(--c-bg);
  color: var(--c-text);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-headline);
  font-weight: 900;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--c-primary);
}

p {
  line-height: 1.7;
}

a {
  color: var(--c-link);
  text-decoration: none;
  transition: color 160ms var(--ease);
}

a:hover {
  text-decoration: underline;
}

ul,
ol {
  list-style: none;
}

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

main {
  display: block;
}

[hidden] {
  display: none !important;
}

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

/* ---------- 3. 排版工具 ---------- */
.headline {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: clamp(2rem, 4vw, 3.5rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--c-primary);
}

.subtitle {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 1.25rem;
  line-height: 1.4;
  color: var(--c-primary-2);
}

.lead {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--c-primary-2);
  max-width: 52ch;
}

.body-text {
  max-width: 60ch;
  color: var(--c-primary);
}

.prose {
  max-width: 72ch;
  line-height: 1.8;
}

.prose p {
  margin-bottom: 1.2em;
}

.prose h2 {
  font-size: 1.5rem;
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.prose h3 {
  font-size: 1.25rem;
  margin-top: 1.4em;
  margin-bottom: 0.4em;
}

.prose ul,
.prose ol {
  margin-bottom: 1.2em;
}

.prose ul {
  list-style: square;
  padding-left: 1.4em;
}

.prose li {
  margin-bottom: 0.4em;
}

.page-title {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -0.02em;
  color: var(--c-primary);
}

.page-subtitle {
  color: var(--c-accent);
  font-size: 1rem;
  max-width: 54ch;
}

.num,
.latin {
  font-family: var(--font-latin);
  font-weight: 700;
  letter-spacing: 0.02em;
}

/* ---------- 4. 布局工具 ---------- */
.container {
  width: min(var(--content-w, 1200px), calc(100vw - 48px));
  margin-inline: auto;
}

.section {
  padding-block: 64px 32px;
}

.section-head {
  margin-bottom: 32px;
}

.grid-6 {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 24px;
}

.grid-span-2 {
  grid-column: span 2;
}

.grid-span-3 {
  grid-column: span 3;
}

.grid-span-4 {
  grid-column: span 4;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 2px solid transparent;
  border-radius: 0;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color var(--ease), border-color var(--ease), color var(--ease);
}

.btn-primary {
  background: var(--c-secondary);
  border-color: var(--c-secondary);
  color: var(--c-text-on-dark);
}

.btn-primary:hover {
  background: var(--c-secondary-2);
  border-color: var(--c-secondary-2);
  color: var(--c-text-on-dark);
  text-decoration: none;
}

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

.btn-outline:hover {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-text-on-dark);
  text-decoration: none;
}

/* ---------- 6. 堆叠面板 ---------- */
.panel {
  position: relative;
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: 0;
  padding: 32px;
  box-shadow: var(--shadow-sm);
}

.panel::before {
  content: '';
  position: absolute;
  top: -1px;
  left: -1px;
  width: 32px;
  height: 32px;
  border-top: 3px solid var(--c-secondary);
  border-left: 3px solid var(--c-secondary);
  pointer-events: none;
}

.panel::after {
  content: '';
  position: absolute;
  right: -1px;
  bottom: -1px;
  width: 32px;
  height: 32px;
  border-right: 1px solid var(--c-accent);
  border-bottom: 1px solid var(--c-accent);
  pointer-events: none;
}

.panel-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.panel-title {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1.375rem;
  color: var(--c-primary);
  letter-spacing: -0.01em;
}

.panel-index {
  font-family: var(--font-latin);
  font-weight: 700;
  font-size: 0.8125rem;
  color: var(--c-accent);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  margin-bottom: 28px;
  font-size: 0.8125rem;
  color: var(--c-accent);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '/';
  color: var(--c-accent);
}

.breadcrumb-link {
  color: var(--c-link);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--c-primary);
  font-weight: 600;
}

/* ---------- 8. 媒体占位 ---------- */
.media-frame {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--gradient-primary);
  border: 1px solid var(--c-border);
  color: var(--c-text-on-dark);
}

.media-frame::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--c-secondary);
}

.media-ratio-4x3 {
  aspect-ratio: 4 / 3;
}

.media-ratio-1x1 {
  aspect-ratio: 1 / 1;
}

/* ---------- 9. 主题筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-block: 8px;
}

.filter-btn {
  appearance: none;
  border: 1px solid var(--c-accent);
  border-radius: 0;
  background: transparent;
  color: var(--c-primary);
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 8px 16px;
  cursor: pointer;
  transition: background-color var(--ease), color var(--ease), border-color var(--ease);
}

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

.filter-btn.is-active {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-text-on-dark);
}

/* ---------- 10. 滚动显现 ---------- */
[data-appear] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 560ms var(--ease), transform 560ms var(--ease);
}

[data-appear].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 11. 头部 ---------- */
.skip-link {
  position: absolute;
  top: -52px;
  left: 16px;
  z-index: 9999;
  background: var(--c-secondary);
  color: var(--c-text-on-dark);
  padding: 12px 20px;
  font-weight: 700;
  font-size: 0.875rem;
  border-radius: 0;
  transition: top 200ms var(--ease);
}

.skip-link:focus {
  top: 12px;
  color: var(--c-text-on-dark);
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--c-primary);
  border-bottom: 1px solid rgba(138, 155, 178, 0.25);
}

.header-inner {
  width: min(var(--content-w, 1200px), calc(100vw - 48px));
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  min-height: var(--header-h, 72px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--c-text-on-dark);
  text-decoration: none;
  flex-shrink: 0;
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.brand-text {
  display: block;
  line-height: 1.25;
}

.brand-name {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1.125rem;
  letter-spacing: -0.01em;
  color: var(--c-text-on-dark);
  display: block;
}

.brand-desc {
  display: block;
  font-size: 0.6875rem;
  color: var(--c-accent);
  letter-spacing: 0.06em;
  margin-top: 2px;
}

.site-nav {
  margin-left: auto;
}

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

.nav-item {
  position: relative;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--c-text-on-dark);
  border: 1px solid transparent;
  text-decoration: none;
  position: relative;
  transition: background-color 200ms var(--ease), border-color 200ms var(--ease);
}

.nav-link:hover {
  background-color: rgba(138, 155, 178, 0.14);
  border-color: rgba(138, 155, 178, 0.35);
  text-decoration: none;
}

.nav-link[aria-current="page"] {
  background-color: rgba(255, 92, 53, 0.14);
  border-color: rgba(255, 92, 53, 0.35);
  color: var(--c-text-on-dark);
}

.nav-link[aria-current="page"]::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--c-secondary);
}

.nav-index {
  font-family: var(--font-latin);
  font-weight: 700;
  font-size: 0.625rem;
  color: var(--c-secondary);
  letter-spacing: 0.04em;
  line-height: 1;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 1px solid var(--c-accent);
  border-radius: 0;
  cursor: pointer;
  transition: border-color var(--ease);
  flex-shrink: 0;
}

.nav-toggle:hover {
  border-color: var(--c-secondary);
}

.nav-toggle-line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--c-text-on-dark);
  transition: transform 220ms var(--ease), opacity 220ms var(--ease);
}

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

/* ---------- 12. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--c-primary);
  color: var(--c-accent);
  border-top: 3px solid var(--c-secondary);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(138, 155, 178, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(138, 155, 178, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
}

.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 64px;
  padding: 64px 0 48px;
}

.footer-brand {
  max-width: 40ch;
}

.footer-logo {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1.375rem;
  color: var(--c-text-on-dark);
  text-decoration: none;
}

.footer-logo:hover {
  text-decoration: none;
  color: var(--c-text-on-dark);
}

.footer-logo-sub {
  font-family: var(--font-latin);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-secondary);
}

.footer-about {
  margin-top: 16px;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--c-accent);
}

.footer-title {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-secondary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(138, 155, 178, 0.2);
}

.footer-links ul,
.footer-contact ul {
  display: grid;
  gap: 10px;
}

.footer-links a,
.footer-contact a {
  color: var(--c-text-on-dark);
  font-size: 0.875rem;
  line-height: 1.5;
}

.footer-links a:hover,
.footer-contact a:hover {
  color: var(--c-secondary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-contact li {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--c-accent);
  word-break: break-word;
}

.footer-bottom {
  position: relative;
  border-top: 1px solid rgba(138, 155, 178, 0.2);
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding-block: 18px 22px;
  font-size: 0.8125rem;
  color: var(--c-accent);
}

.footer-icp {
  font-family: var(--font-latin);
  letter-spacing: 0.06em;
  white-space: nowrap;
}

/* ---------- 13. 响应式调整 ---------- */
@media (min-width: 768px) and (max-width: 1100px) {
  .brand-desc {
    display: none;
  }

  .nav-link {
    padding: 8px 10px;
    font-size: 0.8125rem;
  }

  .nav-index {
    margin-right: 2px;
  }

  .header-inner {
    gap: 16px;
  }
}

@media (max-width: 767px) {
  .container,
  .header-inner {
    width: calc(100vw - 32px);
  }

  .section {
    padding-block: 40px 24px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--c-primary);
    border-bottom: 2px solid var(--c-secondary);
    box-shadow: var(--shadow-md);
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 16px 24px 24px;
  }

  .nav-item {
    width: 100%;
  }

  .nav-link {
    display: flex;
    width: 100%;
    padding: 14px 12px;
    font-size: 1rem;
    border-bottom: 1px solid rgba(138, 155, 178, 0.14);
  }

  .nav-link[aria-current="page"]::after {
    left: 0;
    right: auto;
    width: 4px;
    height: auto;
    top: 8px;
    bottom: 8px;
  }

  .grid-6 {
    grid-template-columns: 1fr;
  }

  .grid-span-2,
  .grid-span-3,
  .grid-span-4 {
    grid-column: span 1;
  }

  .panel {
    padding: 24px 20px;
  }

  .panel-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
}

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

  .footer-bottom-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-grid {
    gap: 32px;
  }
}

/* ---------- 14. 无障碍 ---------- */
@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;
  }

  [data-appear] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}