```css
/* ===== yy4080影院 全站样式 ===== */
/* 主题变量 - 高对比度与可读性优先 */
:root,
[data-theme="light"] {
  --bg: #f0f5fa;
  --surface: #ffffff;
  --primary: #0a4d7a;
  --primary-light: #3b82c4;
  --primary-dark: #083a5c;
  --accent: #e8a838;
  --accent-soft: #fff3d6;
  --text-main: #2d3748;
  --text-strong: #1a202c;
  --text-secondary: #4a5a6a;
  --heading-h1: #0b3b5c;
  --heading-h2: #1e3a5f;
  --heading-h3: #243b53;
  --heading-h4: #334e68;
  --link: #0b4f6c;
  --link-hover: #0b6e8f;
  --border: #dce5ec;
  --nav-bg: rgba(255, 255, 255, 0.82);
  --footer-bg: #0a1e2e;
  --footer-text: #cbd8e9;
  --button-bg: #0a4d7a;
  --button-text: #ffffff;
  --card-bg: #ffffff;
  --shadow: 0 4px 20px rgba(10, 40, 70, 0.08);
  --shadow-hover: 0 8px 30px rgba(10, 40, 70, 0.15);
  --tag-bg: #e6f0f9;
  --tag-text: #0a3b5a;
  --input-bg: #ffffff;
  --placeholder: #5a7184;
  --faq-border: #d0dce8;
  --table-head: #e8eef4;
  --table-row: #ffffff;
  --banner-overlay: rgba(4, 30, 50, 0.65);
  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-border: rgba(255, 255, 255, 0.4);
  --code-bg: #f0f4f8;
  --scrollbar-thumb: #b0c4d8;
  --scrollbar-track: #e8eef4;
}

[data-theme="dark"] {
  --bg: #0b1622;
  --surface: #142433;
  --primary: #5fa8d3;
  --primary-light: #8ac4e8;
  --primary-dark: #3d7ea8;
  --accent: #f0b840;
  --accent-soft: #3a2f14;
  --text-main: #d0dbe7;
  --text-strong: #f0f6fc;
  --text-secondary: #9ab3cc;
  --heading-h1: #d4eaff;
  --heading-h2: #b0d4f0;
  --heading-h3: #9cc4e0;
  --heading-h4: #8ab8d8;
  --link: #7cb8e8;
  --link-hover: #a0d4ff;
  --border: #24405a;
  --nav-bg: rgba(10, 22, 34, 0.82);
  --footer-bg: #060e17;
  --footer-text: #a0bcd8;
  --button-bg: #2a6f97;
  --button-text: #ffffff;
  --card-bg: #13283c;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 8px 32px rgba(0, 0, 0, 0.5);
  --tag-bg: #1b3b55;
  --tag-text: #c0e0ff;
  --input-bg: #1a3044;
  --placeholder: #7a9ab8;
  --faq-border: #2a4a66;
  --table-head: #1a2e42;
  --table-row: #13283c;
  --banner-overlay: rgba(2, 12, 20, 0.75);
  --glass-bg: rgba(20, 36, 52, 0.6);
  --glass-border: rgba(255, 255, 255, 0.08);
  --code-bg: #1e3044;
  --scrollbar-thumb: #2a4a66;
  --scrollbar-track: #0d1b2a;
}

/* ===== 基础重置与全局 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text-main);
  line-height: 1.7;
  transition: background 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
  min-height: 100vh;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(ellipse at 20% 50%, rgba(10, 77, 122, 0.03) 0%, transparent 50%),
              radial-gradient(ellipse at 80% 20%, rgba(232, 168, 56, 0.03) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

.container {
  max-width: 1320px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

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

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

ul,
ol {
  list-style: none;
  padding: 0;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input,
textarea {
  font-family: inherit;
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 8px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
  background-clip: padding-box;
}

/* ===== 导航栏 ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s ease, background 0.3s ease;
}

.navbar.scrolled {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 16px;
}

.logo a {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--heading-h1);
  text-decoration: none;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: opacity 0.2s;
}

.logo a:hover {
  opacity: 0.85;
}

.menu {
  display: flex;
  gap: 4px;
  list-style: none;
  align-items: center;
}

.menu li {
  position: relative;
}

.menu a {
  color: var(--text-strong);
  text-decoration: none;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: 10px;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
  display: block;
  font-size: 0.95rem;
}

.menu a:hover {
  background: color-mix(in srgb, var(--primary) 12%, transparent);
  color: var(--primary);
  transform: translateY(-1px);
}

.menu a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: width 0.25s ease;
}

.menu a:hover::after {
  width: 24px;
}

.actions {
  display: flex;
  gap: 12px;
  align-items: center;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 40px;
  padding: 4px 4px 4px 16px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  max-width: 240px;
}

.search-box:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 15%, transparent);
}

.search-box input {
  border: none;
  background: transparent;
  color: var(--text-main);
  outline: none;
  width: 140px;
  font-size: 0.9rem;
  padding: 6px 0;
}

.search-box input::placeholder {
  color: var(--placeholder);
  font-size: 0.9rem;
}

.search-box button {
  background: var(--button-bg);
  color: var(--button-text);
  border: none;
  border-radius: 40px;
  padding: 7px 16px;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.85rem;
  transition: background 0.2s ease, transform 0.2s ease;
  display: flex;
  align-items: center;
  gap: 4px;
}

.search-box button:hover {
  background: var(--primary-dark);
  transform: scale(1.03);
}

.theme-toggle,
.hamburger {
  background: none;
  border: none;
  color: var(--text-strong);
  font-size: 1.3rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  transition: background 0.2s ease, transform 0.2s ease;
}

.theme-toggle:hover,
.hamburger:hover {
  background: color-mix(in srgb, var(--primary) 10%, transparent);
  transform: rotate(10deg);
}

.hamburger {
  display: none;
  font-size: 1.5rem;
}

/* 移动菜单 */
.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--surface);
  padding: 8px 0;
  border-top: 1px solid var(--border);
  animation: slideDown 0.25s ease;
}

.mobile-menu a {
  padding: 14px 24px;
  color: var(--text-strong);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  font-weight: 500;
  transition: background 0.2s ease, padding-left 0.2s ease;
  font-size: 0.95rem;
}

.mobile-menu a:last-child {
  border-bottom: none;
}

.mobile-menu a:hover {
  background: color-mix(in srgb, var(--primary) 8%, transparent);
  padding-left: 32px;
  color: var(--primary);
}

.mobile-menu.open {
  display: flex;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 20px 0 8px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.breadcrumb a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s;
}

.breadcrumb a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

.breadcrumb span {
  color: var(--text-secondary);
}

/* ===== Banner 主视觉 ===== */
.banner {
  background: linear-gradient(135deg, #0a3d5c 0%, #0a5d7e 50%, #0a6d8f 100%);
  border-radius: 28px;
  margin: 12px 0 40px;
  padding: 56px 48px;
  position: relative;
  color: white;
  box-shadow: 0 8px 32px rgba(6, 40, 60, 0.25);
  overflow: hidden;
  isolation: isolate;
}

.banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.05) 0%, transparent 40%);
  z-index: -1;
}

.banner::after {
  content: '';
  position: absolute;
  top: -40%;
  right: -10%;
  width: 60%;
  height: 80%;
  background: linear-gradient(135deg, transparent 40%, rgba(255, 255, 255, 0.06) 100%);
  transform: rotate(12deg);
  border-radius: 50%;
  z-index: -1;
}

.banner h1 {
  color: #ffffff;
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  line-height: 1.15;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  font-weight: 800;
  letter-spacing: -0.5px;
  max-width: 800px;
}

.banner p {
  color: rgba(255, 255, 255, 0.92);
  font-size: clamp(1rem, 1.5vw, 1.2rem);
  max-width: 680px;
  margin-top: 16px;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.3);
  line-height: 1.7;
}

.banner .btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 28px;
  background: var(--accent);
  color: #0a2a3b;
  padding: 14px 32px;
  border-radius: 60px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}

.banner .btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
  background: #ffd06a;
}

.banner .btn:active {
  transform: translateY(-1px) scale(0.98);
}

/* ===== 标题体系 ===== */
h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--heading-h1);
  margin-bottom: 24px;
}

h2 {
  font-size: clamp(1.6rem, 2.5vw, 2.2rem);
  margin: 48px 0 24px;
  color: var(--heading-h2);
  border-left: 5px solid var(--primary);
  padding-left: 20px;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 20px;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), transparent);
  border-radius: 3px;
}

h3 {
  font-size: 1.35rem;
  margin: 28px 0 16px;
  color: var(--heading-h3);
}

h4 {
  font-size: 1.1rem;
  margin: 16px 0 10px;
  color: var(--heading-h4);
}

p {
  margin-bottom: 16px;
  color: var(--text-main);
  line-height: 1.8;
}

/* ===== 卡片网格 ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--card-bg);
  border-radius: 18px;
  padding: 28px 24px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light), var(--accent));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: color-mix(in srgb, var(--primary) 20%, var(--border));
}

.card:hover::before {
  opacity: 1;
}

.card h3 {
  margin-top: 0;
  font-size: 1.25rem;
}

.card h4 {
  margin-top: 0;
  font-size: 1.1rem;
  color: var(--heading-h4);
}

.card p {
  margin-bottom: 0;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* ===== 文章列表 ===== */
.article-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 16px;
  border-bottom: 1px solid var(--border);
  border-radius: 12px;
  transition: background 0.25s ease, transform 0.25s ease, padding-left 0.25s ease;
  cursor: default;
  position: relative;
}

.article-item:last-child {
  border-bottom: none;
}

.article-item:hover {
  background: color-mix(in srgb, var(--primary) 4%, transparent);
  padding-left: 24px;
  transform: translateX(4px);
}

.article-item h4 {
  margin: 0;
  font-size: 1.05rem;
  color: var(--heading-h3);
  transition: color 0.2s;
  line-height: 1.5;
}

.article-item:hover h4 {
  color: var(--primary);
}

.article-meta {
  color: var(--text-secondary);
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 8px;
  letter-spacing: 0.02em;
}

.article-meta::before {
  content: '📅';
  font-size: 0.9rem;
}

/* ===== 表格 ===== */
.table-wrapper {
  overflow-x: auto;
  border-radius: 16px;
  border: 1px solid var(--border);
  margin: 24px 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th {
  background: var(--table-head);
  color: var(--text-strong);
  font-weight: 600;
  padding: 14px 16px;
  text-align: left;
  white-space: nowrap;
  border-bottom: 2px solid var(--border);
}

td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--table-row);
  color: var(--text-main);
  vertical-align: middle;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: color-mix(in srgb, var(--primary) 4%, var(--table-row));
}

/* ===== FAQ ===== */
.faq-item {
  border: 1px solid var(--faq-border);
  border-radius: 16px;
  padding: 0 24px;
  margin-bottom: 16px;
  background: var(--surface);
  transition: box-shadow 0.25s ease, border-color 0.25s ease;
  overflow: hidden;
}

.faq-item:hover {
  box-shadow: var(--shadow);
  border-color: color-mix(in srgb, var(--primary) 30%, var(--faq-border));
}

.faq-question {
  font-weight: 600;
  padding: 20px 0;
  cursor: pointer;
  color: var(--text-strong);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  font-size: 1.02rem;
  user-select: none;
  transition: color 0.2s;
}

.faq-question:hover {
  color: var(--primary);
}

.faq-question span {
  font-size: 1.3rem;
  transition: transform 0.3s ease;
  color: var(--primary);
  flex-shrink: 0;
  line-height: 1;
}

.faq-item.open .faq-question span {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 0 20px;
  color: var(--text-main);
  border-top: 1px solid var(--border);
  padding-top: 16px;
  line-height: 1.8;
  font-size: 0.95rem;
}

/* ===== HowTo ===== */
.howto-box {
  background: var(--surface);
  border-radius: 20px;
  padding: 32px;
  border: 1px solid var(--border);
  margin: 32px 0;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.howto-box::before {
  content: '📖';
  position: absolute;
  top: 24px;
  right: 24px;
  font-size: 2.4rem;
  opacity: 0.1;
  transform: rotate(-10deg);
}

.howto-box h4 {
  color: var(--primary);
  font-size: 1.1rem;
  margin-top: 24px;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.howto-box h4:first-child {
  margin-top: 0;
}

.howto-box h4::before {
  content: '▸';
  color: var(--primary);
}

.howto-box p {
  margin-bottom: 12px;
  font-size: 0.95rem;
  line-height: 1.9;
}

.howto-box strong {
  color: var(--text-strong);
}

/* ===== 联系卡片 ===== */
#contact .card h4 {
  color: var(--primary);
  font-size: 1rem;
  margin-top: 12px;
}

#contact .card h4:first-child {
  margin-top: 0;
}

#contact .card p {
  font-size: 0.92rem;
  line-height: 1.7;
}

/* ===== 按钮 ===== */
.btn-primary {
  background: var(--button-bg);
  color: var(--button-text);
  padding: 12px 28px;
  border-radius: 40px;
  text-decoration: none;
  display: inline-block;
  font-weight: 600;
  border: none;
  transition: all 0.25s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
  color: #fff;
}

/* ===== 标签 ===== */
.tag {
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 4px 14px;
  border-radius: 40px;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  display: inline-block;
  transition: all 0.2s;
}

.tag:hover {
  background: color-mix(in srgb, var(--primary) 20%, var(--tag-bg));
  transform: scale(1.05);
}

/* ===== 页脚 ===== */
footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  margin-top: 80px;
  padding: 56px 0 24px;
  position: relative;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--primary-light), transparent);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}

.footer-grid h4 {
  color: #ffffff;
  font-size: 1.1rem;
  margin-bottom: 16px;
  position: relative;
  padding-bottom: 8px;
}

.footer-grid h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 28px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

.footer-grid p {
  color: var(--footer-text);
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: 0;
}

footer a {
  color: #8ec5e8;
  transition: color 0.2s ease, padding-left 0.2s ease;
  display: inline-block;
}

footer a:hover {
  color: #ffffff;
  padding-left: 4px;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 32px;
  padding-top: 24px;
  text-align: center;
  color: #8aa8c4;
  font-size: 0.85rem;
}

.copyright p {
  color: #8aa8c4;
  font-size: 0.85rem;
  margin-bottom: 6px;
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  background: var(--button-bg);
  color: var(--button-text);
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  font-size: 22px;
  cursor: pointer;
  z-index: 999;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

/* ===== 毛玻璃效果 ===== */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(160%);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
}

/* ===== 滚动动画 ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.animated {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 交互视觉 ===== */
::selection {
  background: color-mix(in srgb, var(--primary) 25%, transparent);
  color: var(--text-strong);
}

.section-divider {
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 48px 0;
}

/* 区块淡入 */
section {
  animation: sectionFade 0.5s ease both;
}

@keyframes sectionFade {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 响应式适配 ===== */
@media (max-width: 1024px) {
  .container {
    padding: 0 20px;
  }

  .banner {
    padding: 44px 32px;
  }

  .search-box {
    max-width: 180px;
  }

  .search-box input {
    width: 100px;
  }
}

@media (max-width: 768px) {
  .nav-inner {
    height: 60px;
    gap: 8px;
  }

  .logo a {
    font-size: 1.35rem;
  }

  .menu,
  .actions .search-box {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .actions {
    gap: 4px;
  }

  .theme-toggle {
    font-size: 1.2rem;
  }

  .banner {
    padding: 32px 24px;
    border-radius: 20px;
    margin: 8px 0 24px;
  }

  .banner h1 {
    font-size: 1.8rem;
  }

  .banner p {
    font-size: 1rem;
  }

  .banner .btn {
    margin-top: 20px;
    padding: 12px 24px;
    font-size: 0.95rem;
  }

  h2 {
    font-size: 1.5rem;
    margin: 36px 0 16px;
    padding-left: 14px;
  }

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

  .card {
    padding: 20px;
  }

  .faq-item {
    padding: 0 16px;
  }

  .faq-question {
    font-size: 0.95rem;
    padding: 16px 0;
  }

  .howto-box {
    padding: 20px;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    font-size: 18px;
  }

  footer {
    padding: 40px 0 16px;
    margin-top: 48px;
  }

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

  .article-item {
    padding: 16px 12px;
  }

  .article-item:hover {
    padding-left: 16px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .banner {
    padding: 28px 20px;
  }

  .banner h1 {
    font-size: 1.5rem;
  }

  .banner p {
    font-size: 0.92rem;
    line-height: 1.6;
  }

  .banner .btn {
    padding: 10px 20px;
    font-size: 0.9rem;
    margin-top: 16px;
  }

  .theme-toggle {
    width: 32px;
    height: 32px;
  }

  .hamburger {
    width: 32px;
    height: 32px;
    font-size: 1.3rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .search-box button span {
    display: none;
  }
}

/* ===== 深色模式微调 ===== */
[data-theme="dark"] .banner {
  background: linear-gradient(135deg, #0a2438 0%, #0d3a52 50%, #0f4a66 100%);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .banner .btn {
  background: var(--accent);
  color: #0a1e2e;
}

[data-theme="dark"] .banner .btn:hover {
  background: #ffd06a;
}

[data-theme="dark"] .logo a {
  background: linear-gradient(135deg, #7ab7e0, #a0c8e8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="dark"] .card {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

[data-theme="dark"] .card:hover {
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .howto-box::before {
  opacity: 0.05;
}

/* ===== 无障碍与交互细节 ===== */
:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

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

/* 工具类 */
.text-center {
  text-align: center;
}

.mt-0 {
  margin-top: 0;
}

.mb-0 {
  margin-bottom: 0;
}

.hidden {
  display: none !important;
}
```