/* 智控官网（tg.ivpn.me）：zh / en 两套页面共用 */
:root {
  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --ink: #0f172a;
  --ink-2: #334155;
  --mute: #64748b;
  --line: #e2e8f0;
  --pri: #2563eb;
  --pri-ink: #ffffff;
  --pri-soft: #eff4ff;
  --ok: #16a34a;
  --dark: #0b1220;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font: 16px/1.7 system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--pri); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* 顶栏 */
header.top { position: sticky; top: 0; z-index: 10; background: rgba(255, 255, 255, 0.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; gap: 24px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.brand:hover { text-decoration: none; }
nav.links { display: flex; gap: 22px; margin-left: auto; font-size: 15px; }
nav.links a { color: var(--ink-2); }
.lang { font-size: 14px; color: var(--mute); border: 1px solid var(--line); border-radius: 8px; padding: 3px 10px; }

/* 按钮 */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 22px; border-radius: 10px; font-weight: 600; font-size: 16px; border: 1px solid var(--line); background: #fff; color: var(--ink); cursor: pointer; }
.btn:hover { text-decoration: none; border-color: #cbd5e1; }
.btn.pri { background: var(--pri); border-color: var(--pri); color: var(--pri-ink); }
.btn.pri:hover { background: #1d4ed8; }
.btn.sm { padding: 8px 14px; font-size: 14px; }

/* 首屏 */
.hero { padding: 72px 0 40px; background: radial-gradient(1200px 500px at 70% -10%, #dbe7ff 0%, rgba(219, 231, 255, 0) 60%); }
.hero .wrap { display: grid; grid-template-columns: 1fr 1.15fr; gap: 48px; align-items: center; }
.eyebrow { display: inline-block; font-size: 13px; font-weight: 600; color: var(--pri); background: var(--pri-soft); padding: 4px 12px; border-radius: 99px; margin-bottom: 16px; }
.hero h1 { font-size: 44px; line-height: 1.2; margin: 0 0 16px; letter-spacing: -0.5px; }
.hero p.lead { font-size: 18px; color: var(--ink-2); margin: 0 0 26px; }
.hero .cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hero .meta { margin-top: 14px; font-size: 13px; color: var(--mute); }
.shot { border-radius: var(--radius); border: 1px solid var(--line); box-shadow: var(--shadow); overflow: hidden; background: #fff; }
.ticks { list-style: none; padding: 0; margin: 22px 0 0; display: grid; gap: 6px; color: var(--ink-2); font-size: 15px; }
.ticks li::before { content: "✓"; color: var(--ok); font-weight: 700; margin-right: 8px; }

/* 区块 */
section { padding: 72px 0; }
section.alt { background: var(--bg-alt); }
.sec-head { text-align: center; max-width: 720px; margin: 0 auto 44px; }
.sec-head h2 { font-size: 32px; margin: 0 0 10px; letter-spacing: -0.3px; }
.sec-head p { color: var(--mute); margin: 0; font-size: 17px; }

.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feat { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.feat .ic { width: 42px; height: 42px; border-radius: 10px; display: grid; place-items: center; background: var(--pri-soft); font-size: 21px; margin-bottom: 14px; }
.feat h3 { margin: 0 0 6px; font-size: 18px; }
.feat p { margin: 0; color: var(--ink-2); font-size: 15px; }

.show { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; margin-bottom: 64px; }
.show:last-child { margin-bottom: 0; }
.show.rev .txt { order: 2; }
.show h3 { font-size: 24px; margin: 0 0 10px; }
.show p { color: var(--ink-2); margin: 0 0 10px; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: s; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; position: relative; }
.step::before { counter-increment: s; content: counter(s); position: absolute; top: -14px; left: 24px; width: 28px; height: 28px; border-radius: 50%; background: var(--pri); color: #fff; font-weight: 700; display: grid; place-items: center; font-size: 14px; }
.step h3 { margin: 6px 0 6px; font-size: 18px; }
.step p { margin: 0; color: var(--ink-2); font-size: 15px; }

/* 价格 */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; align-items: stretch; }
.plan { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px; display: flex; flex-direction: column; }
.plan.hot { border: 2px solid var(--pri); box-shadow: var(--shadow); position: relative; }
.plan.hot .badge { position: absolute; top: -13px; left: 50%; transform: translateX(-50%); background: var(--pri); color: #fff; font-size: 12px; font-weight: 700; padding: 3px 12px; border-radius: 99px; white-space: nowrap; }
.plan h3 { margin: 0; font-size: 20px; }
.plan .for { color: var(--mute); font-size: 14px; margin: 4px 0 16px; }
.plan .price { font-size: 40px; font-weight: 800; letter-spacing: -1px; }
.plan .price small { font-size: 16px; font-weight: 500; color: var(--mute); letter-spacing: 0; }
.plan .per { color: var(--mute); font-size: 13px; margin-bottom: 18px; }
.plan ul { list-style: none; padding: 0; margin: 0 0 24px; display: grid; gap: 8px; font-size: 15px; color: var(--ink-2); flex: 1; }
.plan ul li::before { content: "✓"; color: var(--ok); font-weight: 700; margin-right: 8px; }
.plan ul li b { color: var(--ink); }
.plans-note { text-align: center; color: var(--mute); font-size: 15px; margin-top: 26px; }

/* 下载 */
.dl { display: flex; align-items: center; justify-content: space-between; gap: 24px; background: var(--dark); color: #e2e8f0; border-radius: 18px; padding: 36px 40px; }
.dl h2 { color: #fff; margin: 0 0 6px; font-size: 28px; }
.dl p { margin: 0; color: #94a3b8; }
.dl .side { text-align: right; flex-shrink: 0; }
.dl .side .meta { font-size: 13px; color: #94a3b8; margin-top: 8px; }

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; }
details { border-bottom: 1px solid var(--line); padding: 16px 4px; }
details summary { cursor: pointer; font-weight: 600; font-size: 17px; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
details summary::-webkit-details-marker { display: none; }
details summary::after { content: "+"; color: var(--mute); font-weight: 400; font-size: 22px; line-height: 1; }
details[open] summary::after { content: "−"; }
details p { color: var(--ink-2); margin: 10px 0 0; }

/* 联系 + 页脚 */
.contact { text-align: center; }
.contact .mail { font-size: 22px; font-weight: 700; }
footer { border-top: 1px solid var(--line); padding: 28px 0; color: var(--mute); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

@media (max-width: 900px) {
  .hero .wrap, .show, .grid3, .steps, .plans { grid-template-columns: 1fr; }
  .show.rev .txt { order: 0; }
  .hero h1 { font-size: 34px; }
  nav.links a.hide-m { display: none; }
  .dl { flex-direction: column; align-items: flex-start; padding: 28px 24px; }
  .dl .side { text-align: left; }
  section { padding: 56px 0; }
}
@media (max-width: 560px) {
  nav.links { gap: 12px; font-size: 14px; }
  .plan.hot { margin-top: 10px; }
}