/* 通用样式 - 所有页面共享 */
:root {
  /* 阿里云风格：科技蓝 + 清爽留白 */
  --primary: #1677ff;
  --primary-dark: #0958d9;
  --primary-light: #69b1ff;
  --accent: #22d3ee;
  --success: #16a34a;
  --text: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-light: #f6f8fc;
  --bg-dark: #0f172a;
  --border: #e2e8f0;
  --shadow: 0 18px 60px rgba(2, 6, 23, 0.10);
  --shadow-sm: 0 8px 24px rgba(2, 6, 23, 0.08);
  --radius: 0;
  --radius-sm: 0;
  --container: 1200px;

  /* 顶栏（阿里云风格：白底、蓝色点缀） */
  --nav-bg: rgba(255, 255, 255, 0.72);
  --nav-bg-solid: rgba(255, 255, 255, 0.96);
  --nav-border: rgba(15, 23, 42, 0.08);
  --nav-text: rgba(15, 23, 42, 0.92);
  --nav-muted: rgba(71, 85, 105, 0.72);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  /* 阿里云风格：干净白底 + 科技蓝光晕 */
  background:
    radial-gradient(1100px 700px at 18% 0%, rgba(22, 119, 255, 0.10), transparent 58%),
    radial-gradient(900px 640px at 88% 8%, rgba(34, 211, 238, 0.10), transparent 58%),
    radial-gradient(900px 700px at 50% 120%, rgba(99, 102, 241, 0.06), transparent 62%),
    linear-gradient(180deg, #ffffff 0%, #f7f9ff 54%, #ffffff 100%);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

/* 仅限制在 MOM 内容区内，避免影响 footer 等官网布局 */
.art21-mom-content .container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* 产品介绍页定位横幅：来自官网（子页使用） */
.product-intro-banner {
  padding: 12px 0;
  background: linear-gradient(90deg, rgba(22, 119, 255, 0.06) 0%, transparent 100%);
  border-bottom: 1px solid rgba(22, 119, 255, 0.12);
  margin-top: 72px;
  font-size: 14px;
  color: var(--text-muted);
}
.product-intro-banner .container {
  display: flex;
  align-items: center;
  gap: 8px;
}
.product-intro-banner a {
  color: var(--primary);
  font-weight: 500;
  transition: color 0.2s;
}
.product-intro-banner a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}
.product-intro-banner .sep {
  color: var(--text-light);
  font-weight: 300;
}
.product-intro-banner span:last-child {
  color: var(--text);
  font-weight: 500;
}

/* 导航栏 */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--nav-border);
  transition: all 0.3s ease;
}

.nav.scrolled {
  background: var(--nav-bg-solid);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  padding: 14px 0;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  min-width: 220px;
}

.brand-logo {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}

.brand-text strong {
  font-size: 18px;
  color: var(--nav-text);
}

.brand-text span {
  font-size: 12px;
  color: var(--nav-muted);
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: center;
  min-width: 0;
  padding: 0 8px;
}

.nav-links a {
  color: rgba(15, 23, 42, 0.82);
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--primary);
}

.nav-links a.active {
  color: var(--primary);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  transition: width 0.3s;
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
.nav-cta {
  display: flex;
  gap: 12px;
  align-items: center;
}

/* 嵌入模式导航：无 logo、无按钮 */
.nav-embed .brand-text-only {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}
.nav-embed .brand-text-only strong {
  font-size: 18px;
  color: var(--nav-text);
}
.nav-embed .brand-text-only span {
  font-size: 12px;
  color: var(--nav-muted);
}
.nav-embed .nav-cta,
.nav-embed .menu-btn {
  display: none;
}

/* 子站导航：明确区分于官网 */
.nav-subsite .brand-subsite {
  color: var(--primary);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.nav-links-subsite .nav-sublabel {
  font-size: 12px;
  color: var(--text-light);
  margin-right: 16px;
  font-weight: 500;
}
.nav-subsite .btn-back-site {
  color: var(--primary);
  border-color: var(--primary);
}
.nav-subsite .btn-back-site:hover {
  background: rgba(22, 119, 255, 0.08);
}

.menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  padding: 8px;
}

/* 顶栏按钮在深色背景下的专用样式 */
.nav .btn-ghost{
  color: rgba(15, 23, 42, 0.88);
  background: rgba(22, 119, 255, 0.06);
  border: 1px solid rgba(22, 119, 255, 0.14);
}
.nav .btn-ghost:hover{
  background: rgba(22, 119, 255, 0.10);
}

/* 移动端抽屉菜单 */
.drawer-overlay{
  position: fixed;
  inset: 0;
  background: rgba(2,6,23,.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
  z-index: 999;
}
.drawer-overlay.open{
  opacity: 1;
  pointer-events: auto;
}
.drawer{
  position: fixed;
  top: 0;
  right: 0;
  height: 100%;
  width: min(360px, 92vw);
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(12px);
  border-left: 1px solid rgba(15, 23, 42, 0.08);
  transform: translateX(100%);
  transition: transform .22s ease;
  z-index: 1000;
  display: flex;
  flex-direction: column;
}
.drawer.open{
  transform: translateX(0);
}
.drawer-header{
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  border-bottom: 1px solid rgba(15, 23, 42, 0.08);
}
.drawer-title{
  font-weight: 700;
  font-size: 16px;
  color: rgba(15, 23, 42, 0.92);
}
.drawer-close{
  background: transparent;
  border: none;
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
  color: rgba(15, 23, 42, 0.55);
}
.drawer-links{
  padding: 10px 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.drawer-links a{
  padding: 12px 12px;
  border-radius: 0;
  color: rgba(15, 23, 42, 0.82);
  font-weight: 600;
}
.drawer-links a.active,
.drawer-links a:hover{
  background: rgba(22, 119, 255, 0.08);
  color: var(--primary);
}
.drawer-cta{
  margin-top: auto;
  padding: 12px 14px 18px;
}

body.drawer-open{
  overflow: hidden;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 10px 26px rgba(22, 119, 255, 0.26);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: white;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
}

.btn-ghost:hover {
  background: var(--bg-light);
}

.btn-large {
  padding: 16px 32px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

/* 通用区块 */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
  line-height: 1.3;
}

.section-subtitle {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 800px;
  margin: 0 auto;
}

/* 页脚 */
.footer {
  background: var(--bg-dark);
  color: white;
  padding: 64px 0 32px;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 64px;
  margin-bottom: 48px;
}

.footer-brand{
  display: flex;
  flex-direction: column;
}

.footer-logo{
  width: 44px;
  height: 44px;
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.7);
  margin-top: 16px;
  font-size: 14px;
}

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

.footer-column h4 {
  font-size: 16px;
  margin-bottom: 16px;
}

.footer-column a {
  display: block;
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
  padding: 8px 0;
  transition: color 0.2s;
}

.footer-column a:hover {
  color: white;
}

/* 子站页脚：简约，明确为子站 */
.footer-subsite {
  background: var(--bg-dark);
}
.footer-subsite-content {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px 0 24px;
}
.footer-subsite-brand p {
  margin: 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 15px;
}
.footer-subsite-desc {
  margin-top: 8px !important;
  font-size: 13px !important;
  color: rgba(255, 255, 255, 0.6) !important;
}
.footer-subsite-links {
  display: flex;
  gap: 24px;
  align-items: center;
}
.footer-subsite-links a {
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
  font-weight: 500;
}
.footer-subsite-links a:hover {
  color: white;
}
@media (max-width: 768px) {
  .footer-subsite-content {
    flex-direction: column;
    align-items: flex-start;
  }
}

.footer-bottom {
  text-align: center;
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.5);
  font-size: 14px;
}

/* 响应式 */
@media (max-width: 1100px) {
  .nav-links { gap: 14px; }
  .nav-links a { font-size: 14px; }
  .nav-inner { gap: 16px; }
  .brand { min-width: 200px; }
  .btn { padding: 10px 16px; font-size: 14px; }
}

@media (max-width: 768px) {
  .nav-links,
  .nav-cta {
    display: none;
  }

  .menu-btn {
    display: block;
  }

  .section-title {
    font-size: 22px;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }

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

/* 图片占位符 */
.image-placeholder {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 48px;
  text-align: center;
  color: var(--text-light);
  font-size: 16px;
  min-height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px dashed var(--border);
}

.image-placeholder.large {
  min-height: 500px;
}