:root {
  --ink: #101820;
  --muted: #657180;
  --line: #dce2e8;
  --paper: #ffffff;
  --wash: #f4f7fa;
  --blue: #1774df;
  --blue-dark: #0e59ad;
  --orange: #ff7a1a;
  --shell: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei UI", "PingFang SC", system-ui, sans-serif;
  line-height: 1.7;
}
img { display: block; max-width: 100%; }
a { color: inherit; }
.shell { width: min(calc(100% - 40px), var(--shell)); margin-inline: auto; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 99; padding: 10px 16px; background: white; }
.skip-link:focus { top: 16px; }

.topbar { position: sticky; top: 0; z-index: 20; color: white; background: rgba(16, 24, 32, .96); border-bottom: 1px solid rgba(255,255,255,.12); backdrop-filter: blur(12px); }
.topbar-inner { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand-mark { width: 42px; height: 42px; display: grid; place-items: center; background: var(--blue); border-radius: 8px; font-size: 22px; font-weight: 900; }
.brand strong, .brand small { display: block; line-height: 1.25; }
.brand small { margin-top: 3px; color: #aeb8c3; font-size: 12px; letter-spacing: .12em; }
nav { display: flex; align-items: center; gap: 28px; }
nav a { color: #d5dbe2; text-decoration: none; font-size: 14px; }
nav a:hover, nav a:focus-visible { color: white; }
.coffee-button { min-height: 52px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 0 24px; color: white; background: var(--orange); border: 0; border-radius: 4px; font: inherit; font-weight: 800; cursor: pointer; transition: transform .18s ease, background .18s ease; }
.coffee-button:hover { background: #e9650a; transform: translateY(-2px); }
.coffee-button:focus-visible { outline: 3px solid rgba(255, 122, 26, .35); outline-offset: 3px; }
.coffee-button-small { min-height: 38px; padding: 0 14px; font-size: 13px; }

.hero { padding: 84px 0 74px; background: linear-gradient(135deg, #f7f9fb 0%, #eef4fa 100%); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.02fr .98fr; align-items: center; gap: 70px; }
.eyebrow, .section-index { margin: 0 0 14px; color: var(--blue); font-size: 12px; font-weight: 800; letter-spacing: .14em; }
h1, h2, h3, p { overflow-wrap: anywhere; }
h1 { margin: 0; max-width: 700px; font-size: clamp(38px, 5vw, 66px); line-height: 1.08; letter-spacing: -.045em; }
h1 span { display: block; color: var(--blue); }
.lead { margin: 26px 0 0; max-width: 650px; color: #53606d; font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.button { min-height: 50px; display: inline-flex; align-items: center; justify-content: center; gap: 14px; padding: 0 22px; border: 1px solid transparent; border-radius: 4px; text-decoration: none; font-weight: 800; transition: transform .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary, .button-download { color: white; background: var(--blue); }
.button-primary:hover, .button-download:hover { background: var(--blue-dark); }
.button-primary span { padding-left: 14px; border-left: 1px solid rgba(255,255,255,.32); font-size: 12px; font-weight: 600; }
.button-ghost { border-color: #cdd6df; background: white; }
.hero-note { margin: 18px 0 0; color: #778492; font-size: 13px; }
.app-preview { width: 100%; min-width: 0; margin: 0; overflow: hidden; background: white; border: 1px solid #d9e0e7; border-radius: 10px; box-shadow: 0 26px 70px rgba(20, 42, 67, .18); transform: rotate(1deg); }
.window-bar { height: 36px; display: flex; align-items: center; gap: 7px; padding: 0 13px; color: #77828d; background: #e9eef3; font-size: 11px; }
.window-bar i { width: 9px; height: 9px; border-radius: 50%; background: #aab5bf; }
.window-bar span { margin-left: 7px; }
.app-preview img { width: 100%; height: auto; object-fit: contain; }
.app-preview figcaption { padding: 12px 16px; color: #77828d; border-top: 1px solid var(--line); font-size: 12px; }

.facts { color: white; background: var(--ink); }
.facts-grid { display: grid; grid-template-columns: repeat(4, 1fr); }
.facts-grid div { min-height: 122px; display: flex; flex-direction: column; justify-content: center; padding: 24px; border-left: 1px solid rgba(255,255,255,.13); }
.facts-grid div:last-child { border-right: 1px solid rgba(255,255,255,.13); }
.facts-grid span { color: #8fa0af; font-size: 12px; }
.facts-grid strong { margin-top: 5px; font-size: 15px; }

.section { padding: 92px 0; }
.section-heading { max-width: 720px; margin-bottom: 40px; }
h2 { margin: 0; font-size: clamp(30px, 4vw, 46px); line-height: 1.18; letter-spacing: -.025em; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature-grid article { padding: 30px; border: 1px solid var(--line); background: white; }
.feature-grid article > span { color: var(--blue); font-weight: 900; }
.feature-grid h3 { margin: 26px 0 10px; font-size: 21px; }
.feature-grid p { margin: 0; color: var(--muted); }

.download-section { color: white; background: var(--ink); }
.download-layout { display: grid; grid-template-columns: 1fr 440px; align-items: center; gap: 80px; }
.download-lead { max-width: 620px; color: #aeb9c4; }
.support-list { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 24px; color: #dbe3ea; font-size: 14px; }
.download-card { padding: 28px; color: var(--ink); background: white; border-top: 5px solid var(--blue); }
.download-card-top { display: flex; justify-content: space-between; color: var(--blue); font-size: 12px; font-weight: 900; letter-spacing: .1em; }
.download-card h3 { margin: 24px 0; font-size: 22px; }
.download-card dl { margin: 0 0 24px; }
.download-card dl div { display: flex; justify-content: space-between; gap: 20px; padding: 8px 0; border-bottom: 1px solid var(--line); }
.download-card dt { color: var(--muted); }
.download-card dd { margin: 0; font-weight: 700; text-align: right; }
.button-download { width: 100%; }
.hash-box { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 10px; margin-top: 16px; padding: 12px; background: var(--wash); }
.hash-box span { color: var(--muted); font-size: 10px; }
.hash-box code { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 10px; }
.hash-box button { padding: 5px 9px; color: var(--blue); background: white; border: 1px solid var(--line); cursor: pointer; }

.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin: 0; padding: 0; list-style: none; }
.steps li { padding: 24px; background: var(--wash); border-top: 3px solid var(--ink); }
.steps li > span { color: var(--blue); font-weight: 900; }
.steps h3 { margin: 24px 0 8px; }
.steps p { margin: 0; color: var(--muted); font-size: 14px; }
.warning { margin-top: 28px; padding: 24px 28px; border-left: 5px solid var(--orange); background: #fff5ed; }
.warning p { margin: 5px 0 0; color: #74503a; }

.coffee-section { padding: 64px 0; color: white; background: #18232d; border-top: 1px solid rgba(255,255,255,.1); }
.coffee-cta { display: flex; align-items: center; justify-content: space-between; gap: 48px; }
.coffee-cta h2 { font-size: clamp(28px, 3.5vw, 42px); }
.coffee-cta p:not(.section-index) { margin: 10px 0 0; color: #aeb9c4; }

.douyin-section { padding: 92px 0; background: #edf2f6; }
.douyin-layout { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 100px; }
.douyin-copy p:not(.section-index) { max-width: 620px; color: var(--muted); font-size: 17px; }
.douyin-copy strong { display: inline-block; margin-top: 10px; padding: 9px 14px; background: white; border-left: 4px solid var(--blue); }
.douyin-button { min-width: 290px; display: flex; align-items: center; gap: 18px; padding: 20px 24px; color: white; text-align: left; background: var(--ink); border: 0; border-radius: 8px; box-shadow: 0 18px 45px rgba(20, 42, 67, .2); cursor: pointer; transition: transform .18s ease, background .18s ease; }
.douyin-button:hover { background: #202e3a; transform: translateY(-3px); }
.douyin-button:focus-visible { outline: 3px solid rgba(23, 116, 223, .35); outline-offset: 4px; }
.douyin-button > span:first-child { width: 50px; height: 50px; display: grid; place-items: center; flex: 0 0 auto; color: var(--ink); background: white; border-radius: 50%; font-size: 30px; font-weight: 900; }
.douyin-button > span:last-child { font-size: 17px; font-weight: 900; }
.douyin-button small { display: block; margin-top: 3px; color: #aeb9c4; font-size: 11px; font-weight: 500; }

footer { color: #aeb8c3; background: #0b1117; }
.footer-inner { min-height: 130px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.footer-inner strong, .footer-inner span { display: block; }
.footer-inner strong { color: white; }
.footer-inner span { font-size: 12px; }
.footer-inner a { color: white; }
.toast { position: fixed; right: 22px; bottom: 22px; z-index: 30; padding: 12px 18px; color: white; background: var(--blue); box-shadow: 0 10px 30px rgba(0,0,0,.22); }
body.modal-open { overflow: hidden; }
.coffee-modal { position: fixed; inset: 0; z-index: 100; display: grid; place-items: center; padding: 24px; }
.coffee-modal[hidden] { display: none; }
.coffee-modal-backdrop { position: absolute; inset: 0; width: 100%; height: 100%; padding: 0; background: rgba(5, 10, 16, .78); border: 0; cursor: default; backdrop-filter: blur(5px); }
.coffee-modal-panel { position: relative; width: min(820px, 100%); max-height: calc(100vh - 48px); overflow: auto; padding: 34px; background: white; border-radius: 10px; box-shadow: 0 28px 90px rgba(0,0,0,.42); }
.coffee-modal-panel:focus { outline: none; }
.coffee-modal-close { position: absolute; top: 14px; right: 16px; width: 40px; height: 40px; display: grid; place-items: center; color: #53606d; background: var(--wash); border: 1px solid var(--line); border-radius: 50%; font-size: 26px; line-height: 1; cursor: pointer; }
.coffee-modal-close:hover { color: white; background: var(--ink); }
.coffee-modal-panel h2 { font-size: 36px; }
.coffee-modal-lead { margin: 8px 0 24px; color: var(--muted); }
.pay-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.pay-card { min-width: 0; padding: 18px; background: var(--wash); border: 1px solid var(--line); }
.pay-card h3 { margin: 0 0 12px; text-align: center; }
.pay-card img { width: 100%; max-height: 460px; object-fit: contain; background: white; }
.coffee-modal-tip { margin: 18px 0 0; color: var(--muted); text-align: center; font-size: 12px; }
.douyin-modal-panel { width: min(480px, 100%); text-align: center; }
.douyin-modal-panel h2 { margin-bottom: 20px; }
.douyin-modal-panel > img { width: 100%; max-height: calc(100vh - 280px); object-fit: contain; border-radius: 6px; }
.douyin-modal-panel > strong { display: block; margin-top: 16px; font-size: 17px; }

@media (max-width: 900px) {
  nav a:nth-child(-n+3) { display: none; }
  .hero-grid, .download-layout, .douyin-layout { grid-template-columns: 1fr; }
  .hero-grid { gap: 48px; }
  .app-preview { max-width: 680px; transform: none; }
  .facts-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid, .steps { grid-template-columns: repeat(2, 1fr); }
  .download-layout { gap: 42px; }
  .download-card { max-width: 560px; }
  .douyin-layout { gap: 42px; }
  .douyin-button { width: min(100%, 360px); }
}

@media (max-width: 560px) {
  .shell { width: min(calc(100% - 28px), var(--shell)); }
  .topbar-inner { min-height: 64px; }
  nav { gap: 16px; }
  nav a { display: none; }
  .coffee-button-small { min-height: 36px; padding: 0 11px; font-size: 12px; }
  .hero { padding: 58px 0; }
  h1 { font-size: 39px; }
  .lead { font-size: 16px; }
  .hero-actions .button { width: 100%; }
  .facts-grid, .feature-grid, .steps { grid-template-columns: 1fr; }
  .facts-grid div { min-height: 96px; border-right: 1px solid rgba(255,255,255,.13); }
  .section, .douyin-section { padding: 64px 0; }
  .download-card { padding: 20px; }
  .hash-box { grid-template-columns: 1fr auto; }
  .hash-box span { grid-column: 1 / -1; }
  .coffee-cta { align-items: flex-start; flex-direction: column; gap: 24px; }
  .coffee-cta .coffee-button { width: 100%; }
  .douyin-button { width: 100%; min-width: 0; }
  .coffee-modal { padding: 12px; }
  .coffee-modal-panel { max-height: calc(100vh - 24px); padding: 28px 16px 20px; }
  .coffee-modal-panel h2 { font-size: 29px; }
  .pay-grid { grid-template-columns: 1fr; }
  .pay-card img { max-height: 360px; }
  .douyin-modal-panel > img { max-height: calc(100vh - 260px); }
  .footer-inner { align-items: flex-start; flex-direction: column; justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}