/* 小耳 VPN / XiaoEr VPN 上架静态站 - 共享样式 */

:root {
  --brand-blue: #1769C2;
  --brand-blue-dark: #125AA3;
  --brand-blue-soft: #E8F1FB;
  --text-primary: #1A1A1A;
  --text-secondary: #4A4A4A;
  --text-tertiary: #6E6E6E;
  --bg-page: #FFFFFF;
  --bg-section: #F7F9FC;
  --bg-card: #FFFFFF;
  --border: #E5E9F0;
  --success: #2E7D32;
  --warning: #C77700;
  --shadow-sm: 0 1px 2px rgba(15, 36, 64, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 36, 64, 0.08);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial,
    sans-serif;
  color: var(--text-primary);
  background: var(--bg-page);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--brand-blue);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--brand-blue-dark);
  text-decoration: underline;
}

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

/* ── 顶部导航 ─────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header__inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.brand:hover {
  text-decoration: none;
  color: var(--brand-blue);
}

.brand__logo {
  width: 32px;
  height: 32px;
  color: var(--brand-blue);
  flex-shrink: 0;
}

.brand__name {
  letter-spacing: 0.5px;
}

.brand__name-en {
  color: var(--text-tertiary);
  font-weight: 400;
  font-size: 0.92em;
  margin-left: 4px;
}

.site-nav {
  display: flex;
  gap: 28px;
  font-size: 0.95rem;
}

.site-nav a {
  color: var(--text-secondary);
  font-weight: 500;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--brand-blue);
  text-decoration: none;
}

@media (max-width: 600px) {
  .site-header__inner {
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 18px;
    gap: 10px;
  }
  .site-nav {
    gap: 18px;
    flex-wrap: wrap;
  }
}

/* ── 主体布局 ─────────────────────────────────────────────── */
main {
  min-height: 60vh;
}

.section {
  padding: 64px 24px;
}

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

.section__inner {
  max-width: 1080px;
  margin: 0 auto;
}

.section__eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--brand-blue);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 10px;
}

.section__title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 14px;
}

.section__lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 720px;
}

@media (max-width: 600px) {
  .section {
    padding: 44px 18px;
  }
  .section__title {
    font-size: 1.45rem;
  }
}

/* ── 首页 Hero ────────────────────────────────────────────── */
.hero {
  padding: 80px 24px 64px;
  background:
    radial-gradient(circle at 18% 18%, rgba(23, 105, 194, 0.08), transparent 45%),
    radial-gradient(circle at 88% 12%, rgba(23, 105, 194, 0.06), transparent 50%),
    var(--bg-page);
}

.hero__inner {
  max-width: 1080px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero__title {
  font-size: 2.6rem;
  line-height: 1.18;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
  margin-bottom: 18px;
}

.hero__title-en {
  display: block;
  color: var(--brand-blue);
  font-size: 1.4rem;
  font-weight: 500;
  margin-top: 6px;
  letter-spacing: 0;
}

.hero__lead {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
  max-width: 520px;
}

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

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__logo-card {
  width: 280px;
  height: 280px;
  background: linear-gradient(135deg, var(--brand-blue) 0%, var(--brand-blue-dark) 100%);
  border-radius: 28% 28% 28% 28% / 32% 32% 32% 32%;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 24px 48px -16px rgba(23, 105, 194, 0.45);
  position: relative;
}

.hero__logo-card::after {
  content: "XiaoEr VPN";
  position: absolute;
  bottom: -36px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-tertiary);
  font-size: 0.92rem;
  letter-spacing: 2px;
  font-weight: 500;
}

.hero__logo-svg {
  width: 160px;
  height: 160px;
  color: #ffffff;
}

@media (max-width: 800px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero__title {
    font-size: 2rem;
  }
  .hero__lead {
    margin-left: auto;
    margin-right: auto;
  }
  .hero__actions {
    justify-content: center;
  }
  .hero__visual {
    order: -1;
  }
  .hero__logo-card {
    width: 200px;
    height: 200px;
  }
  .hero__logo-svg {
    width: 120px;
    height: 120px;
  }
}

/* ── 按钮 ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 0.98rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease,
    border-color 0.15s ease, transform 0.15s ease;
  min-height: 44px;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn--primary {
  background: var(--brand-blue);
  color: #ffffff;
}

.btn--primary:hover {
  background: var(--brand-blue-dark);
  color: #ffffff;
}

.btn--ghost {
  background: transparent;
  color: var(--brand-blue);
  border-color: var(--brand-blue);
}

.btn--ghost:hover {
  background: var(--brand-blue-soft);
  color: var(--brand-blue-dark);
}

.btn--lg {
  padding: 14px 28px;
  font-size: 1.05rem;
}

/* ── 特性卡片网格 ─────────────────────────────────────────── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 36px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px 22px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.feature-card__icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--brand-blue-soft);
  color: var(--brand-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}

.feature-card__icon svg {
  width: 22px;
  height: 22px;
}

.feature-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feature-card__desc {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

@media (max-width: 800px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
}

/* ── 流程 / 步骤 ─────────────────────────────────────────── */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 36px;
  counter-reset: step;
}

.step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px 22px;
  position: relative;
}

.step::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  top: -14px;
  left: 22px;
  background: var(--brand-blue);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
  padding: 4px 10px;
  border-radius: 999px;
}

.step h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 10px 0 8px;
}

.step p {
  color: var(--text-secondary);
  font-size: 0.94rem;
}

@media (max-width: 800px) {
  .steps {
    grid-template-columns: 1fr;
  }
}

/* ── 数据条 ─────────────────────────────────────────────── */
.metric {
  display: flex;
  flex-wrap: wrap;
  gap: 32px 48px;
  margin-top: 24px;
}

.metric__item {
  min-width: 140px;
}

.metric__num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--brand-blue);
  letter-spacing: -0.5px;
}

.metric__label {
  font-size: 0.92rem;
  color: var(--text-tertiary);
  margin-top: 4px;
}

/* ── 长内容（隐私 / 协议）────────────────────────────────── */
.prose {
  max-width: 760px;
  margin: 0 auto;
}

.prose h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 36px 0 12px;
  color: var(--text-primary);
  scroll-margin-top: 90px;
}

.prose h3 {
  font-size: 1.08rem;
  font-weight: 600;
  margin: 24px 0 8px;
  color: var(--text-primary);
}

.prose p,
.prose li {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 10px;
}

.prose ul,
.prose ol {
  margin: 6px 0 16px 22px;
}

.prose code {
  background: var(--bg-section);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  color: var(--text-primary);
}

.prose a {
  font-weight: 500;
}

.prose .updated {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--text-tertiary);
  background: var(--bg-section);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 24px;
}

.prose .note {
  background: #FFF7E6;
  border: 1px solid #F5D78E;
  border-left: 4px solid var(--warning);
  border-radius: 6px;
  padding: 12px 16px;
  margin: 18px 0;
  font-size: 0.92rem;
  color: #6B4900;
}

.prose .note strong {
  color: #4A3300;
}

.toc {
  background: var(--bg-section);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin: 0 0 28px;
}

.toc h4 {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-tertiary);
  margin-bottom: 10px;
}

.toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px 18px;
}

.toc a {
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.toc a:hover {
  color: var(--brand-blue);
}

@media (max-width: 600px) {
  .toc ul {
    grid-template-columns: 1fr;
  }
}

/* ── 下载页卡片 ─────────────────────────────────────────── */
.download-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  margin-top: 24px;
}

.download-card + .download-card {
  margin-top: 18px;
}

.download-card__head {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.download-card__title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
}

.download-card__badge {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--brand-blue-soft);
  color: var(--brand-blue);
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.5px;
}

.download-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  font-size: 0.9rem;
  color: var(--text-tertiary);
  margin: 6px 0 18px;
}

.download-card__meta strong {
  color: var(--text-primary);
  font-weight: 600;
}

.download-card__row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 14px 0;
  border-top: 1px solid var(--border);
}

.download-card__row:first-of-type {
  border-top: none;
}

.download-card__name {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.download-card__name strong {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text-primary);
}

.download-card__name span {
  font-size: 0.85rem;
  color: var(--text-tertiary);
}

.download-card__cta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.download-card__cta .btn {
  min-height: 38px;
  padding: 8px 16px;
  font-size: 0.9rem;
}

.checksum {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.78rem;
  color: var(--text-tertiary);
  word-break: break-all;
  background: var(--bg-section);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 12px;
  margin-top: 6px;
}

/* ── FAQ ─────────────────────────────────────────────────── */
.faq {
  margin-top: 28px;
}

.faq details {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  padding: 16px 20px;
  transition: border-color 0.15s ease;
}

.faq details[open] {
  border-color: var(--brand-blue);
}

.faq summary {
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

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

.faq summary::after {
  content: "+";
  color: var(--brand-blue);
  font-size: 1.4rem;
  font-weight: 400;
  transition: transform 0.15s ease;
  line-height: 1;
}

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

.faq details p {
  margin-top: 12px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ── 页脚 ────────────────────────────────────────────────── */
.site-footer {
  background: #0F1F33;
  color: #B6C2D4;
  padding: 44px 24px 28px;
  margin-top: 60px;
}

.site-footer__inner {
  max-width: 1080px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 36px;
}

.site-footer h4 {
  color: #FFFFFF;
  font-size: 0.92rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 14px;
}

.site-footer p,
.site-footer a {
  color: #B6C2D4;
  font-size: 0.92rem;
  line-height: 1.7;
}

.site-footer a:hover {
  color: #FFFFFF;
}

.site-footer ul {
  list-style: none;
}

.site-footer ul li {
  margin-bottom: 6px;
}

.site-footer__bottom {
  max-width: 1080px;
  margin: 32px auto 0;
  padding-top: 18px;
  border-top: 1px solid #1B2C44;
  font-size: 0.85rem;
  color: #6E7E94;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  justify-content: space-between;
}

@media (max-width: 800px) {
  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .site-footer__bottom {
    flex-direction: column;
  }
}

/* ── 通用 ────────────────────────────────────────────────── */
.muted {
  color: var(--text-tertiary);
}

.divider {
  height: 1px;
  background: var(--border);
  margin: 28px 0;
}

.kbd {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.85em;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-section);
  border: 1px solid var(--border);
}