/* ============================================================
   快柠檬 Falemon 官网 · 设计系统
   主色：柠檬黄 + 深海军蓝（信任感 + 活力）
   ============================================================ */

:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --bg-deep: #0b1b2b;
  --bg-deep-2: #10253a;
  --ink: #0b1b2b;
  --ink-2: #4b5b6b;
  --ink-3: #8a97a5;
  --line: #e5eaf0;
  --brand: #ffc400;
  --brand-strong: #f0a800;
  --brand-soft: #fff6d6;
  --green: #22c55e;
  --red: #ef4444;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 10px 30px rgba(11, 27, 43, 0.08);
  --shadow-lg: 0 18px 50px rgba(11, 27, 43, 0.14);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
  --container: 1140px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  border: 2px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn-lg { padding: 16px 34px; font-size: 17px; }
.btn-brand {
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #4a3400;
  box-shadow: 0 8px 22px rgba(255, 196, 0, 0.35);
}
.btn-brand:hover { box-shadow: 0 12px 28px rgba(255, 196, 0, 0.45); }
.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: #16293d; }
.btn-ghost { background: transparent; border-color: var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--ink-3); }
.btn-outline-light { background: transparent; border-color: rgba(255,255,255,.35); color: #fff; }
.btn-outline-light:hover { border-color: #fff; background: rgba(255,255,255,.08); }
.btn-block { width: 100%; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; }
.brand-badge {
  width: 34px; height: 34px; border-radius: 10px;
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  display: grid; place-items: center; font-size: 18px; color: #4a3400;
  box-shadow: 0 4px 12px rgba(255,196,0,.4);
}
.nav-links { display: flex; align-items: center; gap: 28px; font-size: 15px; color: var(--ink-2); }
.nav-links a:hover { color: var(--ink); }
.nav-links a.active { color: var(--ink); font-weight: 600; }
.nav-cta { display: flex; align-items: center; gap: 12px; }
.nav-toggle { display: none; background: none; border: 0; font-size: 24px; color: var(--ink); line-height: 1; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background:
    radial-gradient(60% 80% at 80% 10%, rgba(255,196,0,.16), transparent 60%),
    linear-gradient(180deg, #0b1b2b, #10253a);
  color: #fff;
  overflow: hidden;
}
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center; padding: 84px 0 76px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px; border-radius: 999px;
  background: rgba(255,196,0,.14); border: 1px solid rgba(255,196,0,.35);
  color: var(--brand); font-size: 13.5px; font-weight: 600; margin-bottom: 22px;
}
.hero h1 { font-size: clamp(34px, 5vw, 52px); letter-spacing: -0.5px; }
.hero h1 .hl { color: var(--brand); }
.hero-sub { margin: 20px 0 30px; color: #b9c6d4; font-size: 17px; max-width: 520px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero-note { margin-top: 14px; color: #7f8fa0; font-size: 13.5px; }
.hero-visual { position: relative; }
.hero-card {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 20px;
  padding: 26px;
  backdrop-filter: blur(6px);
  box-shadow: var(--shadow-lg);
}
.hero-card-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.hero-card-title { font-weight: 700; font-size: 15px; }
.pill { font-size: 12px; padding: 4px 10px; border-radius: 999px; background: rgba(34,197,94,.18); color: #5ce08d; font-weight: 600; }
.server-row { display: flex; align-items: center; gap: 12px; padding: 11px 0; border-bottom: 1px solid rgba(255,255,255,.07); font-size: 14px; }
.server-row:last-of-type { border-bottom: 0; }
.server-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 4px rgba(34,197,94,.15); flex: none; }
.server-flag { flex: none; font-size: 16px; }
.server-name { flex: 1; color: #dbe4ee; }
.server-ping { color: #7f8fa0; font-size: 13px; }
.hero-glow {
  position: absolute; inset: 0; z-index: -1;
  background: radial-gradient(40% 40% at 50% 50%, rgba(255,196,0,.1), transparent 70%);
}

/* ---------- 信任数据条 ---------- */
.trustbar { background: var(--bg-soft); border-top: 1px solid var(--line); }
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; padding: 34px 0; text-align: center; }
.trust-item .num { font-size: 30px; font-weight: 800; color: var(--ink); }
.trust-item .num small { font-size: 16px; color: var(--brand-strong); font-weight: 700; }
.trust-item .label { color: var(--ink-2); font-size: 14px; margin-top: 2px; }

/* ---------- 区块通用 ---------- */
.section { padding: 84px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 48px; }
.section-head .kicker {
  display: inline-block; color: var(--brand-strong); font-weight: 700; font-size: 14px;
  letter-spacing: 2px; text-transform: uppercase; margin-bottom: 10px;
}
.section-head h2 { font-size: clamp(26px, 3.4vw, 36px); }
.section-head p { color: var(--ink-2); margin-top: 12px; font-size: 16px; }

/* ---------- 功能卡片 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px 26px; transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card-icon {
  width: 48px; height: 48px; border-radius: 12px; display: grid; place-items: center;
  font-size: 24px; margin-bottom: 16px;
  background: var(--brand-soft); border: 1px solid rgba(255,196,0,.35);
}
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { color: var(--ink-2); font-size: 14.5px; }

/* ---------- 三步上手 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; counter-reset: step; }
.step {
  position: relative; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 30px 26px 26px;
}
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; top: -16px; left: 26px;
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--ink); color: var(--brand);
  display: grid; place-items: center; font-weight: 800; font-size: 15px;
}
.step h3 { font-size: 17px; margin: 12px 0 8px; }
.step p { color: var(--ink-2); font-size: 14.5px; }
.step-icon { font-size: 34px; margin-top: 6px; }

/* ---------- 平台下载 ---------- */
.platform-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.platform-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 20px; text-align: center; transition: transform .18s ease, box-shadow .18s ease;
}
.platform-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.platform-icon { font-size: 42px; margin-bottom: 12px; }
.platform-card h3 { font-size: 17px; }
.platform-card .os { color: var(--ink-3); font-size: 13px; margin: 2px 0 18px; }
.platform-card .btn { width: 100%; }
.platform-card .btn + .btn { margin-top: 8px; }

/* ---------- 邀请返利 ---------- */
.invite {
  border-radius: 20px; overflow: hidden; position: relative;
  background: linear-gradient(120deg, #1a3350, #0b1b2b);
  color: #fff; padding: 52px 56px; display: flex; align-items: center; justify-content: space-between; gap: 32px;
}
.invite h2 { font-size: clamp(22px, 3vw, 30px); }
.invite h2 .hl { color: var(--brand); }
.invite p { color: #aebccb; margin-top: 10px; max-width: 520px; }
.invite-emoji { font-size: 64px; flex: none; }

/* ---------- FAQ ---------- */
.faq-list { max-width: 760px; margin: 0 auto; }
.faq-item { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-sm); margin-bottom: 12px; overflow: hidden; }
.faq-q {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 18px 22px; background: none; border: 0; text-align: left;
  font-size: 16px; font-weight: 600; color: var(--ink);
}
.faq-q .chev { transition: transform .2s ease; color: var(--ink-3); font-size: 14px; flex: none; }
.faq-item.open .faq-q .chev { transform: rotate(180deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; }
.faq-a-inner { padding: 0 22px 18px; color: var(--ink-2); font-size: 14.5px; }

/* ---------- CTA 横幅 ---------- */
.cta-band { background: var(--bg-deep); color: #fff; text-align: center; padding: 72px 24px; }
.cta-band h2 { font-size: clamp(26px, 3.4vw, 36px); }
.cta-band p { color: #aebccb; margin: 14px auto 30px; max-width: 560px; }
.cta-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ---------- 页脚 ---------- */
.footer { background: var(--bg-deep); color: #8a97a5; padding: 56px 0 30px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.footer h4 { color: #fff; font-size: 15px; margin-bottom: 14px; }
.footer a { display: block; font-size: 14px; padding: 5px 0; }
.footer a:hover { color: var(--brand); }
.footer-about { font-size: 14px; margin-top: 14px; line-height: 1.8; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08); margin-top: 40px; padding-top: 22px;
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: space-between; font-size: 13px;
}
.compliance { font-size: 12.5px; color: #66788a; max-width: 860px; line-height: 1.7; margin-top: 12px; }

/* ---------- 内页 Hero ---------- */
.page-hero { background: linear-gradient(180deg, #0b1b2b, #143049); color: #fff; text-align: center; padding: 74px 0 64px; }
.page-hero h1 { font-size: clamp(30px, 4vw, 42px); }
.page-hero p { color: #aebccb; margin: 14px auto 0; max-width: 600px; font-size: 16px; }

/* ---------- 下载页 ---------- */
.dl-page .platform-grid { margin-bottom: 12px; }
.sys-req { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.sys-req .card { padding: 20px 18px; text-align: center; }
.sys-req .card .os { font-size: 26px; margin-bottom: 6px; }
.sys-req .card p { font-size: 13px; }
.tutorial-step { display: flex; gap: 16px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.tutorial-step:last-child { border-bottom: 0; }
.tutorial-step .num {
  flex: none; width: 34px; height: 34px; border-radius: 50%;
  background: var(--ink); color: var(--brand); display: grid; place-items: center; font-weight: 800;
}
.tutorial-step h4 { font-size: 16px; margin-bottom: 4px; }
.tutorial-step p { color: var(--ink-2); font-size: 14.5px; }

/* ---------- 隐私/条款正文 ---------- */
.prose { max-width: 820px; margin: 0 auto; padding: 64px 24px 84px; }
.prose h2 { font-size: 22px; margin: 40px 0 14px; }
.prose h3 { font-size: 17px; margin: 24px 0 10px; }
.prose p, .prose li { color: var(--ink-2); font-size: 15px; margin-bottom: 12px; }
.prose ul { list-style: disc; padding-left: 22px; }
.prose .meta { color: var(--ink-3); font-size: 13.5px; margin-bottom: 30px; }

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 30px; transform: translateX(-50%) translateY(20px);
  background: var(--ink); color: #fff; padding: 12px 22px; border-radius: 999px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: all .25s ease; z-index: 99;
  box-shadow: var(--shadow-lg); max-width: 90vw; text-align: center;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; padding: 56px 0; }
  .hero-visual { order: -1; max-width: 480px; margin: 0 auto; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
  .sys-req { grid-template-columns: repeat(2, 1fr); }
  .invite { flex-direction: column; text-align: center; padding: 40px 28px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav-links {
    position: absolute; top: 68px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    display: none; padding: 8px 24px 18px; box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--line); }
  .nav-links a:last-child { border-bottom: 0; }
  .nav-cta .btn-ghost { display: none; }
  .nav-toggle { display: block; }
  .feature-grid, .steps, .platform-grid, .sys-req { grid-template-columns: 1fr; }
  .hero-actions .btn { width: 100%; }
  .cta-actions .btn { width: 100%; }
  .section { padding: 60px 0; }
}

/* ---------- Small button (nav language switch etc.) ---------- */
.btn-sm { padding: 8px 16px; font-size: 14px; }