:root {
  color-scheme: light;
  font-family: Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #17202a;
  background: #f6f8f9;
  --ink: #17202a;
  --muted: #65727f;
  --soft: #eef3f4;
  --line: #d9e2e5;
  --panel: #ffffff;
  --night: #071015;
  --night-2: #0c171d;
  --teal: #00b8ad;
  --teal-dark: #008f87;
  --coral: #e0445b;
  --gold: #d7a84b;
  --shadow: 0 22px 60px rgba(3, 12, 18, .22);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--panel); }
button, input, select { font: inherit; }
a { color: inherit; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
  min-height: 66px;
  padding: 10px clamp(18px, 5vw, 56px);
  color: #eef7f7;
  border-bottom: 1px solid rgba(255,255,255,.08);
  background: rgba(7, 16, 21, .96);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-size: 25px;
  font-weight: 820;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand img { width: 34px; height: 34px; }
.brand strong { color: var(--teal); }

.site-nav {
  display: flex;
  justify-content: flex-end;
  gap: clamp(16px, 3vw, 34px);
  color: rgba(238,247,247,.84);
  font-size: 14px;
  font-weight: 720;
}

.site-nav a,
.footer a { text-decoration: none; }
.site-nav a:hover,
.footer a:hover { color: var(--teal); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-actions select {
  height: 38px;
  min-width: 116px;
  padding: 0 10px;
  color: #e7f2f2;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 7px;
  background: #0d1b21;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 7px;
  color: var(--ink);
  background: var(--panel);
  cursor: pointer;
  font-weight: 780;
  text-decoration: none;
  transition: transform .18s ease, border-color .18s ease, background .18s ease;
}

.button:hover { transform: translateY(-1px); }
.button.primary { border-color: var(--teal); color: #041014; background: var(--teal); }
.button.secondary { color: #eef7f7; border-color: rgba(255,255,255,.28); background: rgba(255,255,255,.04); }
.button.ghost { color: #e8f6f6; border-color: rgba(0,184,173,.72); background: transparent; }
.button.danger { color: #b4233d; }
.button:disabled { cursor: not-allowed; opacity: .55; transform: none; }

.hero {
  position: relative;
  min-height: 690px;
  padding: 62px clamp(20px, 4vw, 56px) 58px;
  color: #f5fbfb;
  overflow: hidden;
  background:
    linear-gradient(90deg, rgba(7,16,21,.98), rgba(7,16,21,.88) 48%, rgba(7,16,21,.96)),
    #071015;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 1px;
  background: rgba(255,255,255,.14);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(360px, 520px) minmax(620px, 860px);
  gap: clamp(42px, 4vw, 76px);
  align-items: center;
  width: min(100%, 1520px);
  min-height: 570px;
  margin: 0 auto;
}

.hero-copy {
  position: relative;
  z-index: 1;
  max-width: 520px;
}

.eyebrow {
  margin: 0 0 13px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 820;
}

.eyebrow.light { color: var(--teal-dark); }

h1, h2, h3, p { letter-spacing: 0; }
h1 {
  margin: 0;
  font-size: clamp(40px, 4.4vw, 58px);
  line-height: 1.04;
  font-weight: 860;
  white-space: pre-line;
}

.hero-text {
  max-width: 580px;
  margin: 24px 0 26px;
  color: #c5d1d5;
  font-size: 18px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 26px;
}

.hero-actions .button {
  min-width: 170px;
  min-height: 52px;
}

.hero-benefits {
  display: grid;
  grid-template-columns: repeat(4, max-content);
  gap: 18px 22px;
  margin: 18px 0 24px;
  color: #e1eeee;
  font-size: 14px;
  font-weight: 760;
}

.hero-benefits span {
  position: relative;
  padding-left: 13px;
}

.hero-benefits span::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--teal);
}

.hero-note {
  max-width: 540px;
  color: #91a1a7;
  font-size: 13px;
  line-height: 1.65;
}

.hero-visual {
  position: relative;
  z-index: 1;
  justify-self: stretch;
  width: 100%;
  max-width: 860px;
}

.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.section-band {
  padding: 44px clamp(20px, 6vw, 88px);
  background: #f7fafb;
  border-bottom: 1px solid var(--line);
}

.section-heading {
  max-width: 700px;
  margin: 0 auto 26px;
}

.section-heading.centered { text-align: center; }
.section-heading h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(28px, 3.1vw, 42px);
  line-height: 1.18;
  font-weight: 830;
}

.section-heading p:not(.eyebrow) {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  max-width: 1180px;
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  overflow: hidden;
}

.step {
  min-height: 150px;
  padding: 24px;
  border-right: 1px solid var(--line);
}

.step:last-child { border-right: 0; }
.step span {
  display: block;
  margin-bottom: 18px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 860;
}

.step h3,
.feature-grid h3,
.price-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.step p,
.feature-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.features,
.faq {
  max-width: 1180px;
  margin: 0 auto;
  padding: 72px clamp(20px, 5vw, 40px);
}

.features .section-heading,
.faq .section-heading {
  margin-left: 0;
  margin-right: 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature-grid article {
  padding: 26px 24px 28px 0;
  border-right: 1px solid var(--line);
}

.feature-grid article + article { padding-left: 24px; }
.feature-grid article:last-child { border-right: 0; }

.pricing { padding-top: 56px; }

.billing-toggle {
  display: grid;
  grid-template-columns: 1fr 1fr;
  width: fit-content;
  margin: 0 auto 24px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--panel);
}

.billing-toggle button {
  min-height: 36px;
  padding: 0 18px;
  border: 0;
  border-radius: 5px;
  color: var(--muted);
  background: transparent;
  cursor: pointer;
  font-weight: 760;
}

.billing-toggle button.active {
  color: #fff;
  background: var(--ink);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  max-width: 1180px;
  margin: 0 auto;
}

.price-card {
  position: relative;
  padding: 26px;
  border: 1px solid var(--line);
  border-top: 4px solid var(--teal-dark);
  border-radius: 8px;
  background: var(--panel);
}

.price-card:nth-child(2) {
  border-top-color: var(--gold);
  box-shadow: 0 14px 34px rgba(16, 41, 48, .08);
}

.price-card:nth-child(3) { border-top-color: var(--coral); }
.price-card .plan-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.device-count {
  color: var(--teal-dark);
  font-size: 14px;
  font-weight: 820;
  white-space: nowrap;
}

.price-card .price {
  margin: 22px 0 4px;
  font-size: 38px;
  line-height: 1;
  font-weight: 860;
}

.price-card .period,
.price-card .saving {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.price-card .saving {
  display: inline-block;
  margin-top: 10px;
  padding: 5px 9px;
  border-radius: 6px;
  color: #096963;
  background: #e4f7f5;
  font-weight: 780;
}

.price-card ul {
  display: grid;
  gap: 10px;
  min-height: 112px;
  margin: 24px 0;
  padding: 0;
  color: #41505b;
  line-height: 1.55;
  list-style: none;
}

.price-card li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
}

.price-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .58em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--teal-dark);
}

.price-card .button { width: 100%; }
.pricing-footnote {
  max-width: 760px;
  margin: 18px auto 0;
  color: var(--muted);
  text-align: center;
  font-size: 13px;
  line-height: 1.65;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq details {
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}

.faq summary {
  cursor: pointer;
  color: var(--ink);
  font-size: 18px;
  font-weight: 780;
}

.faq details p {
  max-width: 760px;
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.7;
}

.footer {
  padding: 28px clamp(18px, 6vw, 88px);
  color: #9ba8ad;
  background: var(--night);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  max-width: 1180px;
  margin: auto;
}

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

.account-shell { min-height: calc(100vh - 64px); padding: 28px clamp(16px, 5vw, 64px); background: #f6f8f9; }
.account-grid { display: grid; grid-template-columns: 260px minmax(0, 1fr); gap: 22px; max-width: 1180px; margin: 0 auto; }
.account-nav { align-self: start; padding: 14px; border: 1px solid var(--line); border-radius: 8px; background: #fff; }
.account-nav button { width: 100%; min-height: 40px; border: 0; border-radius: 6px; text-align: left; background: transparent; cursor: pointer; }
.account-nav button.active { color: #fff; background: var(--ink); }
.panel { padding: 22px; border: 1px solid var(--line); border-radius: 8px; background: #fff; }
.panel + .panel { margin-top: 16px; }
.panel h2, .panel h3 { margin-top: 0; }
.login-panel { max-width: 460px; margin: 60px auto; }
.form-row { display: grid; gap: 8px; margin: 14px 0; }
.form-row input { width: 100%; height: 42px; border: 1px solid var(--line); border-radius: 7px; padding: 0 12px; }
.inline-actions { display: flex; flex-wrap: wrap; gap: 9px; }
.status { min-height: 20px; margin-top: 12px; color: var(--muted); font-size: 13px; }
.summary-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.metric { padding: 14px; border: 1px solid var(--line); border-radius: 7px; background: #f9fafb; }
.metric span { display: block; color: var(--muted); font-size: 12px; }
.metric strong { display: block; margin-top: 5px; font-size: 18px; }
.device-list { display: grid; gap: 8px; }
.device-row { display: grid; grid-template-columns: 1fr auto; gap: 12px; padding: 12px; border: 1px solid var(--line); border-radius: 7px; }
.device-row small { color: var(--muted); }
.device-actions { display: flex; gap: 8px; align-items: center; }
.hidden { display: none !important; }

@media (max-width: 980px) {
  .site-header { grid-template-columns: auto auto; }
  .site-nav { display: none; }
  .hero-inner {
    grid-template-columns: 1fr;
    min-height: 0;
  }
  .hero-copy { max-width: 680px; }
  .hero-visual { justify-self: stretch; }
  .hero-benefits { grid-template-columns: repeat(2, max-content); }
  .steps,
  .feature-grid,
  .pricing-grid,
  .summary-grid,
  .account-grid { grid-template-columns: 1fr; }
  .step,
  .feature-grid article {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .step:last-child,
  .feature-grid article:last-child { border-bottom: 0; }
  .feature-grid article,
  .feature-grid article + article { padding: 22px 0; }
}

@media (max-width: 620px) {
  .site-header {
    gap: 12px;
    padding-inline: 14px;
  }
  .brand { font-size: 20px; }
  .brand img { width: 30px; height: 30px; }
  .header-actions select { min-width: 92px; }
  .header-actions .button { display: none; }
  .hero { padding: 42px 18px 34px; }
  h1 { font-size: 40px; }
  .hero-text { font-size: 16px; }
  .hero-actions .button { width: 100%; }
  .hero-benefits { grid-template-columns: 1fr 1fr; gap: 12px; }
  .section-band,
  .features,
  .faq { padding-inline: 18px; }
  .footer-inner { flex-direction: column; }
  .account-nav { display: flex; overflow-x: auto; }
  .account-nav button { min-width: 120px; text-align: center; }
}