/* ============================================================
   Vultr 中文网 (vultr-get.com) — 全站样式
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --bg-primary: #edf1f5;
  --bg-secondary: #f7f9fb;
  --bg-card: #ffffff;
  --bg-header: #1a3a5c;
  --bg-footer: #1a3a5c;
  --bg-copyright: #0f2640;
  --accent: #007BFC;
  --accent-hover: #0066d6;
  --accent-green: #5cb85c;
  --accent-green-hover: #4cae4c;
  --accent-red: #d9534f;
  --text-primary: #111827;
  --text-secondary: #1f2937;
  --text-muted: #4b5563;
  --text-white: #ffffff;
  --border: #d0d5dd;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 4px 12px rgba(0,0,0,.06);
  --radius: 8px;
  --max-width: 1100px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text-primary);
  background: var(--bg-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color .2s;
}

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

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  color: var(--text-primary);
}

p {
  margin-bottom: 1em;
}

ul, ol {
  padding-left: 1.5em;
}

li {
  margin-bottom: .4em;
}

/* ---------- Container ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ============================================================
   导航栏
   ============================================================ */
.nav {
  background: var(--bg-header);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.25);
}

.nav .container {
  display: flex;
  align-items: center;
  gap: 0;
  height: 60px;
}

.nav-brand {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-white) !important;
  white-space: nowrap;
  margin-right: 28px;
  letter-spacing: .02em;
}

.nav-brand:hover {
  color: #a8d4ff !important;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  padding: 0;
  margin: 0;
  flex: 1;
  flex-wrap: wrap;
}

.nav-links li a {
  display: block;
  padding: 6px 10px;
  color: #c5d9f0;
  font-size: .88rem;
  border-radius: 4px;
  transition: background .2s, color .2s;
  white-space: nowrap;
}

.nav-links li a:hover,
.nav-links li a.active {
  background: rgba(255,255,255,.12);
  color: var(--text-white);
}

.nav-cta {
  margin-left: auto;
  flex-shrink: 0;
}

.nav-cta a {
  display: inline-block;
  padding: 7px 18px;
  background: var(--accent-green);
  color: var(--text-white) !important;
  font-size: .88rem;
  font-weight: 600;
  border-radius: 4px;
  transition: background .2s;
  white-space: nowrap;
}

.nav-cta a:hover {
  background: var(--accent-green-hover);
}

/* 汉堡菜单 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  margin-left: auto;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-white);
  border-radius: 2px;
  transition: transform .3s, opacity .3s;
}

/* ============================================================
   Hero 首页
   ============================================================ */
.hero {
  background: linear-gradient(135deg, #0d2440 0%, #1a3a5c 50%, #1d4a7a 100%);
  color: var(--text-white);
  text-align: center;
  padding: 90px 0 70px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='4'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.hero .container {
  position: relative;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-white);
  margin-bottom: 18px;
  text-shadow: 0 2px 8px rgba(0,0,0,.3);
}

.hero-subtitle {
  font-size: 1.15rem;
  color: #b8d4f0;
  max-width: 620px;
  margin: 0 auto 30px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 50px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
  border-top: 1px solid rgba(255,255,255,.15);
  padding-top: 32px;
}

.hero-stat {
  text-align: center;
}

.hero-stat .stat-value {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-white);
  line-height: 1.1;
}

.hero-stat .stat-label {
  display: block;
  font-size: .85rem;
  color: #8db8e0;
  margin-top: 4px;
}

/* ============================================================
   Hero-sm 子页面头部
   ============================================================ */
.hero-sm {
  background: linear-gradient(135deg, #0d2440 0%, #1a3a5c 100%);
  color: var(--text-white);
  padding: 64px 0 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-sm::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='4'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.hero-sm .container {
  position: relative;
}

.hero-sm h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-white);
  margin-bottom: 14px;
  text-shadow: 0 2px 8px rgba(0,0,0,.3);
}

.hero-sm p {
  color: #b8d4f0;
  font-size: 1.05rem;
  max-width: 640px;
  margin: 0 auto;
}

/* compare-table */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  font-size: .92rem;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.compare-table thead th {
  background: var(--bg-header);
  color: var(--text-white);
  padding: 14px 18px;
  text-align: left;
  font-weight: 600;
}

.compare-table thead th:first-child {
  width: 30%;
}

.compare-table tbody td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: middle;
}

.compare-table tbody tr:last-child td {
  border-bottom: none;
}

.compare-table tbody tr:hover td {
  background: var(--bg-secondary);
}

/* ============================================================
   Hero-sm 子页面头部（原版删除，统一在上面）
   ============================================================ */

/* ============================================================
   Section 通用
   ============================================================ */
.section {
  padding: 64px 0;
  background: var(--bg-primary);
}

/* 交替背景 — 仅奇数 section，排除 hero */
section.section:nth-child(odd):not(.hero):not(.hero-sm) {
  background: var(--bg-secondary);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 44px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================================
   套餐卡片
   ============================================================ */
.plan-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 36px;
}

/* 强制 4 列一行 */
.plan-cards.cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

.plan-cards.cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

.plan-cards.cols-2 {
  grid-template-columns: repeat(2, 1fr);
}

.plan-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 22px;
  box-shadow: var(--shadow);
  transition: transform .2s, box-shadow .2s;
  display: flex;
  flex-direction: column;
  position: relative;
}

.plan-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 20px rgba(0,0,0,.12);
}

.plan-card.featured {
  border-color: var(--accent);
  border-width: 2px;
}

.plan-card .badge {
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: var(--text-white);
  font-size: .72rem;
  font-weight: 700;
  padding: 3px 12px;
  border-radius: 20px;
  white-space: nowrap;
  letter-spacing: .05em;
  text-transform: uppercase;
}

.plan-card-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.plan-card-price {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.1;
  margin-bottom: 4px;
}

.plan-card-price span {
  font-size: .85rem;
  font-weight: 400;
  color: var(--text-muted);
}

.plan-card-desc {
  color: var(--text-muted);
  font-size: .88rem;
  margin-bottom: 16px;
  flex: 1;
}

.plan-card-features {
  list-style: none;
  padding: 0;
  margin: 0 0 20px;
  font-size: .88rem;
}

.plan-card-features li {
  padding: 5px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.plan-card-features li:last-child {
  border-bottom: none;
}

.plan-card-features li::before {
  content: '✓';
  color: var(--accent-green);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

.plan-card .btn {
  margin-top: auto;
  text-align: center;
}

/* ============================================================
   系列卡片
   ============================================================ */
.series-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 36px;
}

/* 强制指定列数 */
.series-grid.cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

.series-grid.cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

.series-grid.cols-5 {
  grid-template-columns: repeat(5, 1fr);
}

.series-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform .2s, border-color .2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.series-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent);
}

.series-card-icon {
  font-size: 2rem;
  line-height: 1;
}

.series-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.series-card p {
  font-size: .85rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.5;
}

.series-card a {
  font-size: .85rem;
  font-weight: 600;
  color: var(--accent);
}

/* ============================================================
   优势网格
   ============================================================ */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.advantages-grid.cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

.advantage-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  display: flex;
  gap: 18px;
  align-items: flex-start;
}

.advantage-icon {
  font-size: 2rem;
  flex-shrink: 0;
  line-height: 1;
  margin-top: 2px;
}

.advantage-content h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.advantage-content p {
  font-size: .9rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.6;
}

/* ============================================================
   内容+侧边栏布局
   ============================================================ */
.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 32px;
  align-items: start;
  padding: 48px 0;
}

.content-with-sidebar > main {
  min-width: 0;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 36px 32px;
}

.content-with-sidebar > main .section {
  padding: 0 0 28px;
  background: transparent;
}

.content-with-sidebar > main .section:last-child {
  padding-bottom: 0;
}

.content-with-sidebar > main h2.section-title {
  font-size: 1.45rem;
  font-weight: 700;
  margin: 36px 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
  text-align: left;
}

.content-with-sidebar > main h2 {
  font-size: 1.45rem;
  font-weight: 700;
  margin: 36px 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
  color: var(--text-primary);
}

.content-with-sidebar > main h2:first-child {
  margin-top: 0;
}

.content-with-sidebar > main h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 22px 0 10px;
  color: var(--text-secondary);
}

.content-with-sidebar > main p {
  color: var(--text-secondary);
  line-height: 1.8;
}

.content-with-sidebar > main ul,
.content-with-sidebar > main ol {
  color: var(--text-secondary);
  font-size: .95rem;
  line-height: 1.85;
  margin-bottom: 1em;
}

/* Sidebar — 竖向单列，sticky 跟随滚动 */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 0;
  position: sticky;
  top: 80px;
  align-self: start;
}

.sidebar-widget {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px;
  box-shadow: var(--shadow);
}

/* 快速访问 widget 特殊高亮 */
.sidebar-widget.widget-cta {
  background: var(--bg-card);
  border-color: var(--border);
}

.sidebar-widget.widget-cta h4 {
  color: var(--text-primary);
  border-bottom-color: var(--border);
}

.sidebar-widget.widget-cta p {
  color: var(--text-muted);
  font-size: .85rem;
  margin: 6px 0 0;
}

.sidebar-widget.widget-cta .btn {
  width: 100%;
  text-align: center;
  display: block;
  margin-top: 4px;
  font-size: .9rem;
}

.sidebar-widget.widget-cta ul {
  margin-top: 10px;
}

.sidebar-widget.widget-cta ul li {
  border-bottom-color: #2a5a9c;
}

.sidebar-widget.widget-cta ul li a {
  color: #7ab0d8;
  font-size: .84rem;
}

.sidebar-widget.widget-cta ul li a:hover {
  color: #a8d4ff;
}

.sidebar-widget h4 {
  font-size: .95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--accent);
}

.sidebar-widget ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar-widget ul li {
  margin-bottom: 0;
  border-bottom: 1px solid var(--border);
}

.sidebar-widget ul li:last-child {
  border-bottom: none;
}

.sidebar-widget ul li a {
  display: block;
  padding: 8px 0;
  font-size: .85rem;
  color: var(--text-secondary);
  transition: color .2s, padding-left .2s;
}

.sidebar-widget ul li a:hover {
  color: var(--accent);
  padding-left: 4px;
}

/* ============================================================
   FAQ 手风琴
   ============================================================ */
.faq-list {
  max-width: 780px;
  margin: 40px auto 0;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 10px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 18px 24px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background .2s;
  font-family: inherit;
}

.faq-question:hover {
  background: var(--bg-secondary);
}

.faq-icon {
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--accent);
  flex-shrink: 0;
  transition: transform .3s;
  line-height: 1;
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s ease, padding .35s ease;
  padding: 0 24px;
}

.faq-answer p,
.faq-answer ul,
.faq-answer ol {
  color: var(--text-secondary);
  font-size: .95rem;
  line-height: 1.75;
}

.faq-item.open .faq-answer {
  max-height: 800px;
  padding: 6px 24px 20px;
}

/* ============================================================
   按钮
   ============================================================ */
.btn {
  display: inline-block;
  padding: 11px 26px;
  border-radius: 6px;
  font-size: .95rem;
  font-weight: 600;
  line-height: 1.4;
  cursor: pointer;
  transition: background .2s, color .2s, border-color .2s, transform .15s;
  border: 2px solid transparent;
  text-align: center;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
}

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

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: var(--text-white);
}

.btn-green {
  background: var(--accent-green);
  color: var(--text-white);
  border-color: var(--accent-green);
}

.btn-green:hover {
  background: var(--accent-green-hover);
  border-color: var(--accent-green-hover);
  color: var(--text-white);
}

.btn-outline {
  background: transparent;
  color: var(--text-white);
  border-color: rgba(255,255,255,.7);
}

.btn-outline:hover {
  background: rgba(255,255,255,.12);
  color: var(--text-white);
  border-color: var(--text-white);
}

.btn-lg {
  padding: 14px 36px;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 7px 16px;
  font-size: .82rem;
}

/* ============================================================
   主内容区 h2 标题美化
   ============================================================ */
.content-with-sidebar > main h2 {
  display: flex;
  align-items: center;
  gap: 10px;
}

.content-with-sidebar > main h2::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 1.2em;
  background: var(--accent);
  border-radius: 2px;
  flex-shrink: 0;
}

/* 代码行内 */
.content-with-sidebar > main code {
  background: #f0f4f8;
  border: 1px solid #d0d5dd;
  border-radius: 4px;
  padding: 1px 6px;
  font-size: .88em;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  color: #c0392b;
}

/* 列表美化 */
.content-with-sidebar > main > ul > li,
.content-with-sidebar > main .section > ul > li {
  position: relative;
}

/* ============================================================
   Alert 提示框
   ============================================================ */
.alert {
  padding: 14px 20px;
  border-radius: var(--radius);
  border-left: 4px solid;
  margin: 20px 0;
  font-size: .93rem;
  line-height: 1.6;
}

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

.alert.info {
  background: #e8f4fd;
  border-color: var(--accent);
  color: #1a4a7a;
}

.alert.warning {
  background: #fff8e1;
  border-color: #f59e0b;
  color: #78350f;
}

.alert.success {
  background: #f0fdf4;
  border-color: var(--accent-green);
  color: #14532d;
}

/* ============================================================
   表格（对比页）
   ============================================================ */
.table-wrapper {
  overflow-x: auto;
  margin: 24px 0;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  font-size: .92rem;
}

thead th {
  background: var(--bg-header);
  color: var(--text-white);
  padding: 14px 18px;
  text-align: left;
  font-weight: 600;
  white-space: nowrap;
}

tbody td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: top;
}

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

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

td.highlight {
  font-weight: 600;
  color: var(--accent-green);
}

td.warn {
  color: var(--accent-red);
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--bg-footer);
  color: #a8c0d8;
  padding: 56px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
}

.footer-brand h3 {
  color: var(--text-white);
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: .88rem;
  color: #7a9ab8;
  line-height: 1.7;
  margin-bottom: 0;
}

.footer-col h4 {
  color: var(--text-white);
  font-size: .95rem;
  font-weight: 700;
  margin-bottom: 14px;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col ul li {
  margin-bottom: 0;
}

.footer-col ul li a {
  display: block;
  padding: 5px 0;
  color: #7a9ab8;
  font-size: .88rem;
  transition: color .2s;
}

.footer-col ul li a:hover {
  color: var(--text-white);
}

/* footer-bottom 全宽，在 .container 外面 */
.footer-bottom {
  background: var(--bg-copyright);
  color: #4a6a8a;
  font-size: .82rem;
  text-align: center;
  padding: 16px 20px;
  margin-top: 32px;
}

.footer-bottom a {
  color: #6a8aaa;
}

.footer-bottom a:hover {
  color: var(--text-white);
}

/* ============================================================
   返回顶部
   ============================================================ */
#back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  background: var(--accent);
  color: var(--text-white);
  border: none;
  border-radius: 50%;
  font-size: 1.3rem;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(0,123,252,.4);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity .3s, transform .3s, background .2s;
  opacity: 0;
  pointer-events: none;
  z-index: 999;
}

#back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

#back-to-top:hover {
  background: var(--accent-hover);
  transform: translateY(-3px);
}

/* ============================================================
   辅助工具类
   ============================================================ */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mb-0 { margin-bottom: 0; }
.mt-0 { margin-top: 0; }
.mt-20 { margin-top: 20px; }
.mt-40 { margin-top: 40px; }

.tag {
  display: inline-block;
  padding: 2px 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: .78rem;
  color: var(--text-muted);
  margin-right: 6px;
  margin-bottom: 6px;
}

/* ============================================================
   响应式 — 768px
   ============================================================ */
@media (max-width: 768px) {

  /* 导航 */
  .nav-links {
    display: none;
    flex-direction: column;
    gap: 0;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg-header);
    padding: 10px 0;
    box-shadow: 0 4px 10px rgba(0,0,0,.3);
    z-index: 99;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li a {
    padding: 12px 20px;
    font-size: .95rem;
    border-radius: 0;
  }

  .nav-cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .nav .container {
    flex-wrap: nowrap;
    position: relative;
  }

  /* Hero */
  .hero {
    padding: 60px 0 48px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero-stats {
    gap: 28px;
  }

  .hero-stat .stat-value {
    font-size: 1.6rem;
  }

  /* 卡片布局 */
  .plan-cards,
  .plan-cards.cols-4,
  .plan-cards.cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .series-grid,
  .series-grid.cols-4,
  .series-grid.cols-5 {
    grid-template-columns: repeat(2, 1fr);
  }

  .advantages-grid,
  .advantages-grid.cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 内容+侧边栏 */
  .content-with-sidebar {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 0;
  }

  .content-with-sidebar > main {
    padding: 24px 18px;
  }

  /* 侧边栏在移动端取消 sticky，横向平铺 */
  .sidebar {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 16px;
    padding: 0;
  }

  .sidebar-widget {
    flex: 1 1 240px;
  }

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

  .footer-brand {
    grid-column: 1 / -1;
  }

  /* Section */
  .section {
    padding: 44px 0;
  }

  .section-title {
    font-size: 1.4rem;
  }
}

/* ============================================================
   响应式 — 480px
   ============================================================ */
@media (max-width: 480px) {

  .hero h1 {
    font-size: 1.45rem;
  }

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

  .hero-stats {
    gap: 20px;
  }

  .hero-stat .stat-value {
    font-size: 1.4rem;
  }

  .plan-cards,
  .plan-cards.cols-4,
  .plan-cards.cols-3,
  .plan-cards.cols-2 {
    grid-template-columns: 1fr;
  }

  .series-grid,
  .series-grid.cols-4,
  .series-grid.cols-5,
  .series-grid.cols-3 {
    grid-template-columns: 1fr 1fr;
  }

  .advantages-grid,
  .advantages-grid.cols-3 {
    grid-template-columns: 1fr;
  }

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

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn-lg {
    width: 100%;
    max-width: 280px;
  }

  .section {
    padding: 36px 0;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .faq-question {
    font-size: .92rem;
    padding: 14px 16px;
  }

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

  .faq-item.open .faq-answer {
    padding: 4px 16px 16px;
  }
}