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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  font-size: 16px;
  background-color: var(--bg);
  color: var(--text-main);
  transition: background-color 0.4s ease, color 0.3s ease;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ===== 颜色变量（浅色默认） ===== */
:root {
  --bg: #ffffff;
  --bg-soft: #F0F4FA;
  --bg-gradient: linear-gradient(145deg, #1F3A5F, #2E4E7A);
  --card-bg: #ffffff;
  --text-main: #1F2937;
  --text-title: #111827;
  --text-secondary: #334155;
  --text-link: #1D4ED8;
  --btn-bg: #1F3A5F;
  --btn-text: #FFFFFF;
  --nav-bg: rgba(255,255,255,0.85);
  --footer-bg: #0F172A;
  --footer-text: #E2E8F0;
  --border-color: #E2E8F0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
  --shadow-lg: 0 20px 50px rgba(0,0,0,0.12);
  --glass-bg: rgba(255,255,255,0.7);
  --glass-border: rgba(255,255,255,0.4);
  --accent: #1F3A5F;
  --accent-light: #3B82F6;
  --success: #10B981;
  --warning: #F59E0B;
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 24px;
  --radius-xl: 32px;
}

/* ===== 暗色模式变量 ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0F172A;
    --bg-soft: #1E293B;
    --card-bg: #1E293B;
    --text-main: #E2E8F0;
    --text-title: #FFFFFF;
    --text-secondary: #CBD5E1;
    --text-link: #93C5FD;
    --btn-bg: #3B82F6;
    --btn-text: #FFFFFF;
    --nav-bg: rgba(15,23,42,0.85);
    --footer-bg: #0B1120;
    --border-color: #334155;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 8px 30px rgba(0,0,0,0.5);
    --glass-bg: rgba(30,41,59,0.7);
    --glass-border: rgba(255,255,255,0.08);
  }
}

/* 手动暗色类 */
html.dark {
  --bg: #0F172A;
  --bg-soft: #1E293B;
  --card-bg: #1E293B;
  --text-main: #E2E8F0;
  --text-title: #FFFFFF;
  --text-secondary: #CBD5E1;
  --text-link: #93C5FD;
  --btn-bg: #3B82F6;
  --btn-text: #FFFFFF;
  --nav-bg: rgba(15,23,42,0.85);
  --footer-bg: #0B1120;
  --border-color: #334155;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-md: 0 8px 30px rgba(0,0,0,0.5);
  --glass-bg: rgba(30,41,59,0.7);
  --glass-border: rgba(255,255,255,0.08);
}

/* ===== 基础文字 ===== */
h1, h2, h3, h4, h5 {
  color: var(--text-title);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: 1.2rem; }
h3 { font-size: clamp(1.1rem, 1.5vw, 1.35rem); }
h4 { font-size: 1.1rem; }

p { margin-bottom: 0.8rem; }

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

a:hover {
  color: var(--accent-light);
  text-decoration: none;
}

/* ===== 导航栏 ===== */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: box-shadow 0.3s ease, background 0.3s ease;
}

.top-nav.sticky {
  box-shadow: var(--shadow-md);
}

.top-nav a {
  color: var(--text-main);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0.2rem;
  position: relative;
  transition: color 0.2s;
}

.top-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-light);
  transition: width 0.3s ease;
}

.top-nav a:hover::after {
  width: 100%;
}

/* ===== 移动菜单按钮 ===== */
#mobileMenuBtn {
  display: none;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.4rem 1rem;
  border-radius: 30px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s;
}

#mobileMenuBtn:hover {
  background: var(--bg-soft);
}

/* ===== 移动导航面板 ===== */
#mobileNav {
  display: none;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  animation: slideDown 0.3s ease;
}

#mobileNav.open {
  display: block;
}

#mobileNav a {
  display: block;
  padding: 0.7rem 0;
  font-weight: 500;
}

/* ===== 动画 ===== */
@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

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

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(59,130,246,0.4); }
  50% { box-shadow: 0 0 0 15px rgba(59,130,246,0); }
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* ===== 滚动进入动画 ===== */
.fade-in-section {
  opacity: 0;
  transform: translateY(25px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in-section.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 主 Banner ===== */
.hero-banner {
  background: linear-gradient(145deg, #1F3A5F, #2E4E7A, #1F3A5F);
  background-size: 200% 200%;
  animation: gradientShift 15s ease infinite;
  border-radius: var(--radius-xl);
  padding: 3.5rem 2.5rem;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(31, 58, 95, 0.35);
}

.hero-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  transform: rotate(20deg);
  animation: float 6s ease-in-out infinite;
}

.hero-banner h1 {
  color: #FFFFFF;
  font-size: clamp(1.8rem, 4.5vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 1rem;
  text-shadow: 0 2px 20px rgba(0,0,0,0.2);
}

.hero-banner p {
  color: rgba(255,255,255,0.9);
  font-size: 1.1rem;
  max-width: 600px;
  line-height: 1.8;
}

.hero-banner .hero-badge {
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.25);
  padding: 0.8rem 2rem;
  border-radius: 50px;
  display: inline-block;
  font-weight: 700;
  font-size: 1.4rem;
  box-shadow: 0 8px 20px rgba(0,0,0,0.15);
  animation: pulseGlow 3s infinite;
}

/* ===== 通用卡片 ===== */
.card, .article-card, .faq-item, .howto-box, .team-box, .service-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 1.5rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card:hover, .article-card:hover, .service-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-light);
}

/* ===== 毛玻璃效果 ===== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

/* ===== 按钮样式 ===== */
.btn, button {
  background: var(--btn-bg);
  color: var(--btn-text);
  border: none;
  padding: 0.6rem 1.5rem;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  overflow: hidden;
}

.btn:hover, button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(59, 130, 246, 0.35);
  filter: brightness(1.1);
  color: #fff;
}

.btn::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::after {
  left: 100%;
}

/* 暗色按钮 */
button.dark-mode-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.4rem 1.2rem;
  border-radius: 50px;
}

button.dark-mode-btn:hover {
  background: var(--bg-soft);
  box-shadow: none;
  filter: none;
}

/* ===== 区块标题 ===== */
.section-title {
  font-size: clamp(1.4rem, 2.5vw, 1.9rem);
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 1.5rem;
  position: relative;
  padding-left: 1.2rem;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 70%;
  background: linear-gradient(180deg, var(--accent), var(--accent-light));
  border-radius: 3px;
}

/* ===== 内容区块 ===== */
.section-block {
  margin: 3rem 0;
}

/* ===== 产品服务网格 ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.service-card {
  padding: 2rem 1.5rem;
  text-align: left;
}

.service-card .service-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  display: inline-block;
}

.service-card h3 {
  margin-bottom: 0.8rem;
}

/* ===== 文章卡片网格 ===== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.article-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: all 0.3s ease;
}

.article-card .article-meta {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.8rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.article-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.8rem;
  line-height: 1.5;
}

.article-card p {
  color: var(--text-secondary);
  flex-grow: 1;
  font-size: 0.95rem;
}

.article-card .read-more {
  margin-top: 1rem;
  font-weight: 600;
  color: var(--text-link);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap 0.3s ease;
}

.article-card .read-more:hover {
  gap: 0.6rem;
  color: var(--accent-light);
}

/* ===== 品牌介绍区域 ===== */
.brand-section {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.brand-main {
  flex: 2;
  min-width: 300px;
}

.brand-aside {
  flex: 1;
  min-width: 250px;
  background: var(--bg-soft);
  border-radius: var(--radius-lg);
  padding: 1.8rem;
  border: 1px solid var(--border-color);
}

.brand-aside h4 {
  margin-bottom: 1rem;
  padding-bottom: 0.8rem;
  border-bottom: 2px solid var(--border-color);
}

.brand-aside p {
  font-size: 0.95rem;
  margin-bottom: 0.6rem;
}

/* ===== FAQ 样式 ===== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  border-radius: var(--radius-md);
  padding: 1.2rem 1.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: var(--accent-light);
  box-shadow: var(--shadow-sm);
}

.faq-item.active {
  border-color: var(--accent-light);
  background: var(--bg-soft);
}

.faq-question {
  font-weight: 600;
  color: var(--text-title);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1rem;
  gap: 1rem;
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--accent-light);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  margin-top: 0.8rem;
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.8;
  animation: slideDown 0.3s ease;
}

.faq-item.active .faq-answer {
  display: block;
}

/* ===== HowTo 区域 ===== */
.howto-section {
  background: var(--bg-soft);
  padding: 2.5rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-color);
}

.howto-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.howto-grid ol {
  padding-left: 1.5rem;
  margin: 1rem 0;
}

.howto-grid ol li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

.howto-grid ul {
  padding-left: 1.5rem;
  margin: 1rem 0;
}

.howto-grid ul li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

/* ===== 联系区域 ===== */
.contact-section {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  background: var(--bg-soft);
  padding: 2.5rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-color);
}

.contact-info {
  flex: 1;
  min-width: 280px;
}

.contact-info p {
  display: flex;
  align-items: flex-start;
  gap: 0.8rem;
  margin-bottom: 0.8rem;
}

.contact-info p strong {
  min-width: 80px;
  display: inline-block;
}

/* ===== 表格样式 ===== */
table {
  border-collapse: separate;
  border-spacing: 0;
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
  margin: 1rem 0;
}

th {
  background: var(--bg-soft);
  color: var(--text-title);
  font-weight: 600;
  text-align: left;
  padding: 12px 16px;
  border-bottom: 2px solid var(--border-color);
}

td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-main);
}

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

tr:hover td {
  background: var(--bg-soft);
}

/* ===== Footer ===== */
footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 3rem 1.5rem;
  margin-top: 3rem;
  position: relative;
}

footer h3, footer h4 {
  color: #FFFFFF;
  margin-bottom: 1rem;
}

footer a {
  color: #A5B4FC;
  transition: color 0.3s;
}

footer a:hover {
  color: #FFFFFF;
}

footer hr {
  border: none;
  border-top: 1px solid rgba(255,255,255,0.1);
  margin: 1.5rem 0;
}

.footer-content {
  max-width: 1300px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  justify-content: space-between;
}

.footer-bottom {
  text-align: center;
  padding-top: 1rem;
  font-size: 0.9rem;
  opacity: 0.8;
}

/* ===== 返回顶部 ===== */
#backTop {
  background: linear-gradient(135deg, var(--accent-light), var(--accent));
  color: white;
  border: none;
  padding: 0.7rem 1.8rem;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

#backTop.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

#backTop:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 25px rgba(59, 130, 246, 0.5);
}

/* ===== 输入框 ===== */
input, textarea, select {
  width: 100%;
  padding: 0.8rem 1rem;
  background: var(--bg);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  font-family: inherit;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

/* ===== 图片懒加载样式 ===== */
img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}

/* ===== 徽章/标签 ===== */
.badge {
  display: inline-block;
  padding: 0.25rem 0.8rem;
  background: var(--bg-soft);
  border: 1px solid var(--border-color);
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin: 0.2rem;
}

.badge-primary {
  background: rgba(59, 130, 246, 0.1);
  border-color: rgba(59, 130, 246, 0.3);
  color: var(--accent-light);
}

/* ===== 分割线 ===== */
.divider {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 2rem 0;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-banner {
    padding: 2.5rem 1.5rem;
  }

  .hero-banner .hero-badge {
    margin-top: 1rem;
  }
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
  }

  .top-nav .nav-links {
    display: none;
  }

  #mobileMenuBtn {
    display: block;
  }

  .hero-banner {
    padding: 2rem 1.2rem;
    border-radius: var(--radius-lg);
    flex-direction: column;
    text-align: center;
  }

  .hero-banner h1 {
    font-size: 1.6rem;
  }

  .hero-banner p {
    font-size: 0.95rem;
  }

  .hero-banner .hero-badge {
    font-size: 1.2rem;
    padding: 0.6rem 1.5rem;
    margin-top: 1rem;
  }

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

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

  .brand-section {
    flex-direction: column;
  }

  .howto-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .contact-section {
    padding: 1.5rem;
    flex-direction: column;
  }

  .footer-content {
    flex-direction: column;
    gap: 1.5rem;
  }

  .section-block {
    margin: 2rem 0;
  }

  .faq-item {
    padding: 1rem;
  }

  .card, .article-card {
    padding: 1.2rem;
  }

  #backTop {
    bottom: 1.2rem;
    right: 1.2rem;
    padding: 0.6rem 1.2rem;
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  .hero-banner {
    padding: 1.5rem 1rem;
  }

  .hero-banner h1 {
    font-size: 1.3rem;
  }

  .hero-banner .hero-badge {
    font-size: 1rem;
    padding: 0.5rem 1.2rem;
  }

  h2 {
    font-size: 1.3rem;
  }

  h3 {
    font-size: 1rem;
  }

  .card, .article-card {
    padding: 1rem;
  }

  .howto-section {
    padding: 1.5rem;
  }

  .section-title {
    padding-left: 0.8rem;
  }
}

/* ===== 打印样式 ===== */
@media print {
  .top-nav, footer, #backTop, .dark-mode-btn {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .card, .article-card {
    box-shadow: none;
    border: 1px solid #ddd;
  }
}

/* ===== 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;
    scroll-behavior: auto !important;
  }
}

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

/* ===== 文本选择 ===== */
::selection {
  background: rgba(59, 130, 246, 0.2);
  color: var(--text-title);
}

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

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

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-light);
}

/* ===== 通用工具类 ===== */
.text-center { text-align: center; }
.text-secondary { color: var(--text-secondary); }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.mt-1 { margin-top: 0.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-2 { margin-bottom: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-4 { margin-bottom: 2rem; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

/* 弹性布局工具 */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }

/* 网格 */
.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* 隐藏 */
.hidden { display: none; }

/* 圆角 */
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: 9999px; }

/* 阴影 */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

/* 背景 */
.bg-soft { background: var(--bg-soft); }
.bg-white { background: var(--card-bg); }

/* 文本截断 */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.line-clamp-3 {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}