:root {
  --bg: #f5f5f7;
  --surface: #ffffff;
  --surface-strong: #fbfbfd;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #d9d9de;
  --blue: #0071e3;
  --blue-soft: #e8f2ff;
  --green: #2f9e44;
  --yellow: #f5c542;
  --red: #b42318;
  --red-soft: #fff1f0;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.08);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 clamp(18px, 5vw, 72px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  background: rgba(251, 251, 253, 0.86);
  backdrop-filter: blur(20px);
}

.brand {
  display: inline-flex;
  align-items: center;
  min-width: 0;
  flex: 0 1 auto;
  max-width: 58vw;
}

.brand strong,
.brand small {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.brand strong {
  font-size: clamp(16px, 2.1vw, 20px);
  line-height: 1.15;
  letter-spacing: 0;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
}

.nav {
  display: flex;
  gap: clamp(16px, 2.5vw, 32px);
  color: #3f3f45;
  font-size: 14px;
  font-weight: 700;
}

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

.header-link,
.primary-btn,
.secondary-btn,
.download-grid a,
.back-top {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 0 20px;
  font-weight: 800;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.header-link,
.primary-btn {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 10px 26px rgba(0, 113, 227, 0.22);
}

.header-link:hover,
.primary-btn:hover,
.download-grid a:hover {
  transform: translateY(-1px);
}

.secondary-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
}

.register-btn {
  background: #111;
  box-shadow: 0 10px 26px rgba(17, 17, 17, 0.18);
}

.register-note {
  position: relative;
  max-width: 650px;
  margin: 0 0 18px;
  border: 1px solid rgba(0, 113, 227, 0.18);
  border-radius: 18px;
  background:
    linear-gradient(90deg, rgba(0, 113, 227, 0.1), rgba(255, 255, 255, 0.82)),
    #fff;
  color: #35536f;
  padding: 15px 18px 15px 46px;
  font-size: 15px;
  font-weight: 750;
  box-shadow: 0 12px 28px rgba(0, 113, 227, 0.08);
}

.register-note::before {
  position: absolute;
  top: 17px;
  left: 18px;
  display: grid;
  width: 18px;
  height: 18px;
  place-items: center;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  content: "i";
  font-size: 12px;
  font-weight: 900;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  gap: clamp(34px, 6vw, 78px);
  align-items: center;
  min-height: 680px;
  padding: clamp(72px, 8vw, 110px) clamp(18px, 7vw, 90px) 64px;
  overflow: hidden;
}

.hero-copy {
  max-width: 720px;
}

.eyebrow {
  margin-bottom: 12px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(44px, 5vw, 68px);
  line-height: 1.08;
  letter-spacing: 0;
}

.title-main,
.title-sub {
  display: block;
}

.title-sub {
  margin-top: 8px;
  color: var(--blue);
  font-size: 0.74em;
  font-weight: 900;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(30px, 3.4vw, 46px);
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 21px;
  line-height: 1.28;
}

.hero-text {
  max-width: 650px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: 20px;
  font-weight: 600;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 22px;
}

.notice-line {
  max-width: 640px;
  border-left: 4px solid var(--blue);
  border-radius: 12px;
  background: var(--blue-soft);
  color: #17446f;
  padding: 14px 16px;
  font-size: 14px;
  font-weight: 700;
}

.device-stage {
  position: relative;
  min-height: 500px;
}

.ipad-frame,
.iphone-frame {
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: #111;
  box-shadow: var(--shadow);
}

.ipad-frame {
  position: absolute;
  top: 20px;
  right: 0;
  width: min(560px, 92%);
  min-height: 390px;
  border-radius: 34px;
  padding: 18px;
}

.ipad-frame::before {
  position: absolute;
  top: 50%;
  right: 8px;
  width: 4px;
  height: 42px;
  border-radius: 99px;
  background: #444;
  content: "";
  transform: translateY(-50%);
}

.ipad-bar {
  width: 72px;
  height: 6px;
  margin: 0 auto 18px;
  border-radius: 99px;
  background: #333;
}

.settings-list {
  display: grid;
  gap: 14px;
  border-radius: 22px;
  background: #f5f5f7;
  padding: 26px;
}

.settings-list div {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 6px 12px;
  align-items: center;
  border-radius: 16px;
  background: #fff;
  padding: 18px;
}

.settings-list small {
  grid-column: 2;
  color: var(--muted);
}

.app-dot {
  grid-row: span 2;
  width: 42px;
  height: 42px;
  border-radius: 12px;
}

.app-dot.blue {
  background: linear-gradient(145deg, #4aa3ff, #006ee6);
}

.app-dot.green {
  background: linear-gradient(145deg, #63d471, #238b45);
}

.app-dot.dark {
  background: linear-gradient(145deg, #222, #555);
}

.iphone-frame {
  position: absolute;
  right: min(400px, 52%);
  bottom: 0;
  width: 220px;
  min-height: 420px;
  border-radius: 40px;
  padding: 14px;
}

.notch {
  position: absolute;
  top: 12px;
  left: 50%;
  width: 76px;
  height: 22px;
  border-radius: 0 0 14px 14px;
  background: #111;
  transform: translateX(-50%);
  z-index: 2;
}

.phone-screen {
  min-height: 390px;
  border-radius: 30px;
  background: linear-gradient(180deg, #fff, #eef5ff);
  padding: 58px 18px 18px;
}

.screen-label {
  color: var(--blue);
  font-size: 13px;
  font-weight: 900;
}

.phone-screen h2 {
  margin: 12px 0 10px;
  font-size: 28px;
}

.phone-screen p {
  color: var(--muted);
  font-size: 14px;
}

.mini-apps {
  display: grid;
  gap: 10px;
  margin-top: 28px;
}

.mini-apps span {
  border-radius: 14px;
  background: #fff;
  padding: 13px 14px;
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.08);
  font-weight: 900;
}

.section {
  padding: clamp(58px, 7vw, 92px) clamp(18px, 7vw, 90px);
}

.section > * {
  max-width: 1160px;
  margin-right: auto;
  margin-left: auto;
}

.section-heading {
  max-width: 800px;
  margin-bottom: 34px;
  text-align: center;
}

.section-heading p:last-child {
  color: var(--muted);
}

.prep-grid,
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.prep-grid article,
.download-grid article,
.step-card,
.faq-list details {
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.05);
}

.prep-grid article {
  padding: 24px;
}

.prep-grid span {
  display: inline-grid;
  width: 40px;
  height: 40px;
  margin-bottom: 18px;
  place-items: center;
  border-radius: 50%;
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 900;
}

.prep-grid p,
.download-grid p,
.step-card p,
.faq-list p {
  margin-bottom: 0;
  color: var(--muted);
}

.steps-section {
  background: var(--surface-strong);
}

.flow {
  display: grid;
  gap: 16px;
}

.step-card {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  gap: 20px;
  padding: 26px;
}

.step-number {
  display: grid;
  width: 54px;
  height: 54px;
  place-items: center;
  border-radius: 18px;
  background: #111;
  color: #fff;
  font-size: 22px;
  font-weight: 900;
}

.tip,
.warning {
  margin-top: 16px;
  border-radius: 16px;
  padding: 13px 15px;
  font-size: 14px;
  font-weight: 800;
}

.tip {
  background: var(--blue-soft);
  color: #17446f;
}

.warning {
  background: var(--red-soft);
  color: var(--red);
}

.app-checks {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.app-checks span {
  border: 1px solid #c9def8;
  border-radius: 999px;
  background: var(--blue-soft);
  color: #17446f;
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 800;
}

.download-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.download-grid article {
  display: flex;
  min-height: 286px;
  flex-direction: column;
  align-items: flex-start;
  padding: 30px;
}

.platform-logo {
  display: grid;
  width: 56px;
  height: 56px;
  margin-bottom: 20px;
  place-items: center;
  border-radius: 16px;
  overflow: hidden;
  background: #fff;
}

.platform-logo img {
  width: 84%;
  height: 84%;
  object-fit: contain;
}

.download-grid h3 {
  min-height: 30px;
  margin-bottom: 10px;
}

.download-grid p {
  min-height: 74px;
}

.download-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  width: 100%;
  margin-top: auto;
}

.download-grid a {
  width: 100%;
  min-width: 0;
  padding: 0 14px;
  background: #111;
  color: #fff;
  text-align: center;
  white-space: nowrap;
}

.download-grid a.android-link {
  border: 1px solid rgba(17, 17, 17, 0.2);
  background: #fff;
  color: var(--ink);
  box-shadow: none;
}

.safety-section {
  background: #111;
  color: #fff;
}

.safety-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(24px, 5vw, 56px);
  align-items: start;
}

.safety-panel .eyebrow {
  color: #8cc6ff;
}

.safety-panel p {
  color: #c9c9cf;
}

.safety-list {
  display: grid;
  gap: 12px;
}

.safety-list div {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  padding: 16px 18px;
  color: #f3f3f5;
  font-weight: 750;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  overflow: hidden;
}

.faq-list summary {
  position: relative;
  min-height: 62px;
  padding: 18px 60px 18px 22px;
  cursor: pointer;
  font-weight: 900;
  list-style: none;
}

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

.faq-list summary::after {
  position: absolute;
  top: 50%;
  right: 22px;
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: 50%;
  background: var(--bg);
  color: var(--blue);
  content: "+";
  transform: translateY(-50%);
}

.faq-list details[open] summary::after {
  background: var(--blue);
  color: #fff;
  content: "-";
}

.faq-list p {
  padding: 0 22px 22px;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(18px, 7vw, 90px);
  border-top: 1px solid var(--line);
  background: #fff;
}

.back-top {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--blue);
}

@media (max-width: 1060px) {
  .nav {
    display: none;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: 0;
    gap: 28px;
    padding-top: 58px;
  }

  .device-stage {
    min-height: 420px;
  }

  .prep-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .site-header {
    min-height: 66px;
    padding: 0 14px;
  }

  .brand strong {
    font-size: 14px;
  }

  .brand small,
  .header-link {
    display: none;
  }

  .hero {
    padding: 34px 18px 36px;
  }

  h1 {
    font-size: clamp(32px, 8.6vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: 30px;
  }

  .hero-text {
    margin-bottom: 20px;
    font-size: 17px;
  }

  .register-note,
  .notice-line {
    font-size: 14px;
  }

  .register-note {
    margin-bottom: 14px;
    border-radius: 16px;
    padding: 13px 15px 13px 42px;
  }

  .register-note::before {
    top: 15px;
    left: 15px;
  }

  .hero-actions,
  .primary-btn,
  .secondary-btn {
    width: 100%;
  }

  .device-stage {
    min-height: 360px;
  }

  .ipad-frame {
    position: relative;
    top: auto;
    right: auto;
    width: 100%;
    min-height: 260px;
    border-radius: 28px;
    padding: 14px;
  }

  .iphone-frame {
    right: 12px;
    bottom: 0;
    width: 160px;
    min-height: 300px;
    border-radius: 34px;
  }

  .phone-screen {
    min-height: 272px;
    padding: 50px 16px 16px;
    border-radius: 26px;
  }

  .phone-screen h2 {
    font-size: 21px;
  }

  .settings-list {
    gap: 10px;
    padding: 14px;
  }

  .settings-list div {
    grid-template-columns: 36px minmax(0, 1fr);
    padding: 12px;
  }

  .app-dot {
    width: 36px;
    height: 36px;
  }

  .section {
    padding: 50px 18px;
  }

  .section-heading {
    text-align: left;
  }

  .prep-grid,
  .download-grid,
  .safety-panel {
    grid-template-columns: 1fr;
  }

  .download-actions {
    grid-template-columns: 1fr;
  }

  .download-actions a {
    width: 100%;
  }

  .step-card {
    grid-template-columns: 1fr;
    padding: 22px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .hero {
    gap: 22px;
  }

  .hero-actions {
    gap: 10px;
  }

  .device-stage {
    display: none;
  }

  .prep-grid article,
  .download-grid article,
  .step-card,
  .faq-list details,
  .admin-card {
    border-radius: 20px;
  }
}

.admin-page {
  min-height: 100vh;
}

.admin-header {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 0 clamp(18px, 5vw, 72px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  background: rgba(251, 251, 253, 0.9);
  backdrop-filter: blur(20px);
}

.admin-main {
  padding: clamp(42px, 6vw, 78px) clamp(18px, 7vw, 90px);
}

.admin-shell {
  display: grid;
  gap: 22px;
  max-width: 1060px;
  margin: 0 auto;
}

.admin-intro {
  max-width: 720px;
}

.admin-intro h1 {
  margin-bottom: 14px;
  font-size: clamp(34px, 4vw, 54px);
  line-height: 1.12;
}

.admin-intro p:last-child {
  color: var(--muted);
  font-weight: 650;
}

.admin-card {
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 24px;
  background: var(--surface);
  padding: clamp(22px, 4vw, 34px);
  box-shadow: 0 12px 34px rgba(0, 0, 0, 0.05);
}

.login-card {
  display: grid;
  max-width: 460px;
  gap: 16px;
}

.admin-card h2 {
  margin-bottom: 0;
  font-size: 24px;
}

.admin-card label,
.platform-field label {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.admin-card input {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  padding: 0 14px;
}

.settings-card {
  display: grid;
  gap: 22px;
}

.settings-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.settings-head p {
  margin: 6px 0 0;
  color: var(--muted);
}

.platform-fields {
  display: grid;
  gap: 16px;
}

.platform-field {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 18px;
}

.platform-field legend {
  grid-column: 1 / -1;
  padding: 0 8px;
  color: var(--ink);
  font-size: 18px;
  font-weight: 900;
}

.global-register-field,
.login-card {
  grid-template-columns: 1fr;
}

.admin-status {
  min-height: 24px;
  color: var(--muted);
  font-weight: 800;
}

.admin-status[data-type="success"] {
  color: var(--green);
}

.admin-status[data-type="error"] {
  color: var(--red);
}

@media (max-width: 760px) {
  .admin-header {
    padding: 0 14px;
  }

  .admin-header .brand {
    max-width: calc(100% - 116px);
  }

  .admin-header .header-link {
    display: inline-flex;
  }

  .settings-head {
    align-items: stretch;
    flex-direction: column;
  }

  .platform-field {
    grid-template-columns: 1fr;
  }

  .settings-head .primary-btn,
  .login-card .primary-btn {
    width: 100%;
  }
}