:root {
  --primary: #475669;
  --primary-d: #37455a;
  --primary-l: #e8edf2;
  --gradient: linear-gradient(135deg, #5c7086 0%, #475669 55%, #2d3b4c 100%);
  --remind: #f5b623;
  --remind-d: #d9940a;
  --remind-l: #fff6e0;
  --bg: #f0f2f5;
  --surface: #ffffff;
  --text: #1a222e;
  --muted: #6b7a8e;
  --border: #dde3ea;
  --dark: #1a222e;
  --green: #2fb344;
  --red: #e5484d;
  --shadow-sm: 0 1px 2px rgba(30, 40, 55, .06), 0 1px 3px rgba(30, 40, 55, .08);
  --shadow: 0 4px 14px rgba(30, 40, 55, .10);
  --shadow-lg: 0 10px 28px rgba(30, 40, 55, .14);
  --maxw: 1280px;
  --nav-h: 64px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* {
  box-sizing: border-box;
  border-radius: 0 !important;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 12px);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.65;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding-top: var(--nav-h);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color .2s ease, background .2s ease;
}

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

h1, h2, h3, h4, h5 {
  line-height: 1.25;
  margin: 0;
  color: var(--text);
}

.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: 20px;
}

/* 顶部导航 */
#site-header {
  position: fixed;
  inset-inline: 0;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  max-width: var(--maxw);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 20px;
  height: var(--nav-h);
}

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

.brand-logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

.brand-name {
  font-size: 18px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -.2px;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 8px;
}

.nav-links > a {
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  padding: 8px 14px;
}

.nav-links > a:hover,
.nav-links > a.active {
  color: var(--primary-d);
  background: var(--primary-l);
}

#menu-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border);
  background: #fff;
  cursor: pointer;
  padding: 0;
}

.menu-bar {
  display: block;
  width: 20px;
  height: 2px;
  margin-inline: auto;
  background: var(--text);
}

.mobile-menu {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 10px 20px 18px;
  border-bottom: 1px solid var(--border);
  background: #fff;
}

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

.mobile-menu > a {
  padding: 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.mobile-menu > a:hover {
  background: var(--primary-l);
  color: var(--primary-d);
}

.mobile-cta {
  justify-content: center;
  text-align: center;
  margin-top: 8px;
  color: #fff !important;
}

/* 按钮通用 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all .2s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--primary-d);
  box-shadow: var(--shadow);
}

.btn-ghost {
  background: #fff;
  color: var(--text);
  border-color: var(--border);
}

.btn-ghost:hover {
  background: var(--primary-l);
  color: var(--primary-d);
  border-color: var(--primary-l);
}

.btn-lg {
  padding: 14px 32px;
  font-size: 16px;
}

.nav-cta {
  padding: 9px 18px;
  font-size: 14px;
  color: #fff !important;
}

.nav-cta:hover {
  background: var(--primary-d) !important;
  color: #fff !important;
}

/* Hero 区域 */
.hero {
  position: relative;
  padding: 60px 0 72px;
  background: linear-gradient(180deg, #e9edf1 0%, var(--bg) 80%);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  color: var(--primary-d);
  background: var(--primary-l);
  border: 1px solid rgba(71, 86, 105, .2);
  padding: 5px 12px;
  margin-bottom: 18px;
}

.hero-text h1 {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: -.01em;
  line-height: 1.25;
}

.grad-text {
  color: var(--primary-d);
  font-weight: 800;
}

.lead {
  font-size: 16px;
  color: var(--muted);
  margin: 18px 0 24px;
  max-width: 44em;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.hero-stats {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  max-width: 580px;
}

.hero-stats li {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 12px 10px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.hero-stats strong {
  display: block;
  font-size: 20px;
  font-weight: 800;
  color: var(--primary-d);
}

.hero-stats span {
  font-size: 13px;
  color: var(--muted);
}

.hero-note {
  margin-top: 20px;
  font-size: 14px;
  color: var(--muted);
}

.promo {
  margin-top: 14px;
  font-size: 14px;
  color: var(--text);
  background: var(--remind-l);
  border: 1px solid var(--remind);
  border-left: 4px solid var(--remind);
  padding: 10px 14px;
}

.promo code {
  font-family: ui-monospace, Menlo, Consolas, monospace;
  background: rgba(30, 40, 55, .08);
  padding: 2px 6px;
  font-weight: 700;
}

.hero-media {
  position: relative;
}

.hero-cover {
  width: 100%;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  background: #fff;
}

/* 区块通用 */
.section {
  padding: 64px 0;
}

.section-soft {
  background: var(--bg);
}

.section-white {
  background: var(--surface);
  border-block: 1px solid var(--border);
}

.section-head {
  max-width: 740px;
  margin: 0 auto 40px;
  text-align: center;
}

.section-head h2 {
  font-size: clamp(22px, 3.2vw, 30px);
  font-weight: 800;
  letter-spacing: -.01em;
}

.section-head p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 15px;
}

/* 卡片网格 */
.grid-3 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.grid-4 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 24px 22px;
  box-shadow: var(--shadow-sm);
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: var(--primary);
}

.card-icon {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-l);
  color: var(--primary-d);
  margin-bottom: 14px;
  font-size: 18px;
  font-weight: 700;
}

.card-icon.accent {
  background: var(--remind-l);
  color: var(--remind-d);
}

.card h3 {
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 8px;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

/* 套餐卡片 */
.plan {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 26px 22px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.plan-bar {
  display: block;
  height: 4px;
  margin: -26px -22px 20px;
  background: var(--gradient);
}

.plan-featured {
  border-color: var(--primary);
  box-shadow: 0 8px 24px rgba(71, 86, 105, .18);
}

.plan-badge {
  position: absolute;
  top: 14px;
  right: 14px;
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  padding: 4px 10px;
  text-transform: uppercase;
}

.plan-badge.amber {
  background: var(--remind-d);
}

.plan-name {
  font-size: 18px;
  font-weight: 800;
}

.plan-price {
  font-size: 32px;
  font-weight: 800;
  margin: 10px 0 2px;
  color: var(--text);
}

.plan-price .cur {
  font-size: 18px;
  margin-right: 2px;
  color: var(--primary-d);
}

.plan-price .per {
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  margin-left: 4px;
}

.plan-traffic {
  color: var(--primary-d);
  font-weight: 700;
  font-size: 14px;
  margin: 0 0 16px;
}

.plan-feats {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  flex: 1;
}

.plan-feats li {
  position: relative;
  padding: 8px 0 8px 24px;
  font-size: 13.5px;
  color: var(--text);
  border-top: 1px solid var(--border);
}

.plan-feats li:first-child {
  border-top: 0;
}

.plan-feats li::before {
  content: "+";
  position: absolute;
  left: 0;
  top: 8px;
  color: var(--primary-d);
  font-weight: 800;
  font-size: 14px;
}

.plan-cta {
  width: 100%;
}

/* 测速表格 */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

table.tbl {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  min-width: 580px;
}

table.tbl th, table.tbl td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}

table.tbl th {
  background: var(--primary-l);
  color: var(--primary-d);
  font-weight: 700;
}

table.tbl tr:last-child td {
  border-bottom: 0;
}

.tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 8px;
  background: var(--primary-l);
  color: var(--primary-d);
}

.tag.ok {
  background: #e6f6ea;
  color: #1f7a34;
}

/* FAQ 列表 */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 4px 20px;
  box-shadow: var(--shadow-sm);
}

.faq-item summary {
  cursor: pointer;
  list-style: none;
  font-weight: 700;
  font-size: 15px;
  padding: 14px 0;
  position: relative;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 12px;
  font-size: 20px;
  color: var(--primary);
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* CTA 带状条 */
.section-cta {
  background: var(--bg);
  padding: 0 0 60px;
}

.cta-band {
  background: var(--gradient);
  padding: 44px 24px;
  text-align: center;
  color: #fff;
  box-shadow: var(--shadow);
  border: 1px solid rgba(0,0,0,.08);
}

.cta-band h2 {
  font-size: clamp(22px, 3.2vw, 28px);
  font-weight: 800;
  margin-bottom: 10px;
  color: #fff;
}

.cta-band p {
  opacity: .92;
  margin: 0 auto 24px;
  max-width: 42em;
  font-size: 15px;
}

.cta-band .btn-primary {
  background: #fff;
  color: var(--primary-d);
}

.cta-band .btn-primary:hover {
  background: #f1f3f6;
}

/* 页脚 */
#site-footer {
  position: relative;
  background: var(--dark);
  color: #9fb2c6;
  padding: 48px 0 24px;
  font-size: 13px;
  border-top: 3px solid var(--primary);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 28px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 800;
  font-size: 17px;
  margin-bottom: 12px;
}

.footer-logo {
  width: 32px;
  height: 32px;
}

.footer-col p {
  color: #9fb2c6;
  font-size: 13px;
  line-height: 1.7;
  max-width: 280px;
  margin: 0;
}

.footer-head {
  display: flex;
  align-items: center;
  gap: 7px;
  color: rgba(255, 255, 255, .6);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .7px;
  margin-bottom: 12px;
  font-weight: 700;
}

.footer-head::before {
  content: "";
  width: 12px;
  height: 2px;
  background: var(--primary);
}

.footer-col a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 0;
  color: #9fb2c6;
  font-size: 13px;
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .08);
  padding-top: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  color: #6b7a8e;
  font-size: 12px;
}

.footer-bottom-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-bottom-links a {
  color: #6b7a8e;
}

.footer-bottom-links a:hover {
  color: #fff;
}

/* 响应式断点 */
@media (min-width: 640px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero { padding: 68px 0 80px; }
}

@media (min-width: 900px) {
  .nav-links { display: flex; }
  #menu-toggle { display: none; }
  .hero-inner { grid-template-columns: 1.05fr .95fr; gap: 48px; }
  .grid-4 { grid-template-columns: repeat(4, 1fr); }
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
  .section { padding: 80px 0; }
}

@media (min-width: 1200px) {
  .footer-grid { grid-template-columns: 2.2fr 1fr 1.3fr 1fr 1fr; }
}

@media (max-width: 560px) {
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 44px 0; }
  .cta-band { padding: 32px 16px; }
  .hero-actions .btn { width: 100%; }
}