/* ============================================================
   乐行助手 lexingcai.cn — 主样式表
   移动优先 · 品牌色取自 Logo（青绿 + 珊瑚红）
   ============================================================ */

:root {
  --teal: #35c6be;
  --teal-dark: #1fa8a0;
  --teal-light: #e6f8f6;
  --coral: #ff6b6b;
  --coral-dark: #f0554d;
  --coral-light: #ffecec;
  --ink: #1f2a37;
  --ink-soft: #5b6b7b;
  --muted: #8a99a8;
  --line: #eef2f5;
  --bg: #ffffff;
  --bg-alt: #f6fafb;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow-sm: 0 4px 14px rgba(31, 42, 55, .06);
  --shadow: 0 12px 34px rgba(31, 42, 55, .10);
  --shadow-lg: 0 24px 60px rgba(31, 42, 55, .16);
  --grad-brand: linear-gradient(135deg, var(--teal) 0%, var(--coral) 130%);
  --maxw: 1180px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; scroll-padding-top: 82px; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-tap-highlight-color: transparent;
}

/* 键盘可访问性：清晰焦点轮廓 */
:focus-visible { outline: 3px solid var(--teal-dark); outline-offset: 2px; border-radius: 6px; }

img { max-width: 100%; display: block; height: auto; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.container-narrow { max-width: 820px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px 28px; border-radius: 999px; font-size: 16px; font-weight: 700;
  border: none; cursor: pointer; transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
  line-height: 1; white-space: nowrap;
}
.btn:active { transform: translateY(1px) scale(.99); }
.btn-primary { background: var(--grad-brand); color: #fff; box-shadow: 0 10px 24px rgba(53, 198, 190, .38); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(240, 85, 77, .34); }
.btn-ghost { background: rgba(255, 255, 255, .14); color: #fff; border: 1.5px solid rgba(255, 255, 255, .55); backdrop-filter: blur(4px); }
.btn-ghost:hover { background: rgba(255, 255, 255, .26); transform: translateY(-2px); }
.btn-dark { background: var(--ink); color: #fff; box-shadow: 0 10px 24px rgba(31, 42, 55, .22); }
.btn-dark:hover { transform: translateY(-2px); background: #2b3a4b; }
.btn-sm { padding: 10px 18px; font-size: 14px; }
.btn-block { width: 100%; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; gap: 18px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; }
.brand-logo { border-radius: 10px; }
.brand-name { background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent; letter-spacing: .5px; }
.main-nav { display: flex; gap: 26px; margin-left: auto; }
.main-nav a { color: var(--ink-soft); font-weight: 600; font-size: 15px; position: relative; transition: color .18s; }
.main-nav a:hover { color: var(--teal-dark); }
.main-nav a::after { content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px; background: var(--grad-brand); transition: width .22s; border-radius: 2px; }
.main-nav a:hover::after { width: 100%; }
.nav-cta { margin-left: 8px; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; margin-left: auto; }
.nav-toggle span { width: 24px; height: 2.5px; background: var(--ink); border-radius: 2px; transition: .25s; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }
.mobile-menu { display: none; flex-direction: column; padding: 8px 20px 18px; border-top: 1px solid var(--line); background: #fff; }
.mobile-menu a { padding: 13px 4px; font-weight: 600; color: var(--ink-soft); border-bottom: 1px solid var(--line); }
.mobile-menu a:last-child { border-bottom: none; }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; color: #fff; }
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(1200px 600px at 85% -10%, rgba(255, 255, 255, .18), transparent 60%),
    linear-gradient(135deg, #2bb8b0 0%, #35c6be 38%, #ff7a6b 100%);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(rgba(255,255,255,.12) 1.4px, transparent 1.6px);
  background-size: 26px 26px; opacity: .5;
  -webkit-mask-image: linear-gradient(180deg, #000, transparent 70%);
  mask-image: linear-gradient(180deg, #000, transparent 70%);
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: 40px;
  padding: 72px 20px 84px;
}
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255, 255, 255, .18); border: 1px solid rgba(255, 255, 255, .4);
  padding: 7px 15px; border-radius: 999px; font-size: 13px; font-weight: 700; letter-spacing: .5px;
  backdrop-filter: blur(4px);
}
.hero-text h1 { font-size: clamp(28px, 4.4vw, 46px); line-height: 1.22; font-weight: 900; margin: 18px 0 14px; letter-spacing: .5px; }
.hero-text .accent { color: #fff2b0; }
.lead { font-size: clamp(16px, 2vw, 19px); color: rgba(255, 255, 255, .92); max-width: 520px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 30px 0 18px; }
.hero-note {
  display: flex; align-items: flex-start; gap: 8px; font-size: 13.5px; color: rgba(255, 255, 255, .9);
  background: rgba(0, 0, 0, .12); border: 1px solid rgba(255, 255, 255, .22);
  padding: 11px 15px; border-radius: var(--radius-sm); max-width: 540px;
}
.hero-note svg { flex: none; margin-top: 2px; }

/* 手机模型 */
.hero-visual { position: relative; height: 480px; display: flex; justify-content: center; align-items: center; }
.phone {
  position: absolute; width: 236px; border-radius: 34px; overflow: hidden;
  background: #fff; border: 8px solid #12202b; box-shadow: var(--shadow-lg);
}
.phone img { width: 100%; height: 100%; object-fit: cover; }
.phone-back { transform: rotate(-8deg) translate(-64px, 8px); z-index: 1; height: 460px; opacity: .96; }
.phone-front { transform: rotate(6deg) translate(64px, -6px); z-index: 2; height: 470px; }

/* ---------- 信任条 ---------- */
.trustbar { background: #fff; border-bottom: 1px solid var(--line); }
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; padding: 26px 20px; }
.trust-item { text-align: center; display: flex; flex-direction: column; gap: 2px; }
.t-num { font-size: 24px; font-weight: 900; background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }
.t-label { font-size: 14px; color: var(--ink-soft); font-weight: 600; }

/* ---------- 通用 Section ---------- */
.section { padding: 76px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 46px; }
.section-head h2 { font-size: clamp(24px, 3.4vw, 34px); font-weight: 900; letter-spacing: .5px; }
.section-head h2::after { content: ""; display: block; width: 54px; height: 4px; border-radius: 4px; background: var(--grad-brand); margin: 14px auto 0; }
.section-head p { color: var(--ink-soft); margin-top: 16px; font-size: 16px; }

/* ---------- 功能特色 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 26px; box-shadow: var(--shadow-sm); transition: transform .22s ease, box-shadow .22s ease;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.f-icon {
  width: 58px; height: 58px; border-radius: 16px; display: grid; place-items: center;
  font-size: 28px; margin-bottom: 16px;
}
.i-teal { background: var(--teal-light); }
.i-coral { background: var(--coral-light); }
.feature-card h3 { font-size: 19px; font-weight: 800; margin-bottom: 8px; }
.feature-card p { color: var(--ink-soft); font-size: 15px; }

/* ---------- 界面预览 ---------- */
.shots-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 34px; justify-items: center; }
.shot { text-align: center; max-width: 320px; }
.shot-frame {
  background: var(--grad-brand); padding: 12px; border-radius: 40px; box-shadow: var(--shadow);
  transition: transform .25s ease;
}
.shot:hover .shot-frame { transform: translateY(-8px); }
.shot-frame img { border-radius: 30px; width: 100%; background: #fff; }
.shot figcaption { margin-top: 18px; color: var(--ink-soft); font-weight: 600; font-size: 15px; }

/* ---------- 下载卡片 ---------- */
.dl-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 26px; max-width: 860px; margin: 0 auto; }
.dl-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 34px 30px; text-align: center; box-shadow: var(--shadow-sm); transition: transform .22s, box-shadow .22s;
}
.dl-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.dl-icon { font-size: 46px; margin-bottom: 10px; }
.dl-card h3 { font-size: 21px; font-weight: 800; margin-bottom: 10px; }
.dl-card p { color: var(--ink-soft); font-size: 15px; margin-bottom: 22px; min-height: 48px; }
.dl-meta { display: block; margin-top: 14px; font-size: 13px; color: var(--muted); }
.dl-safe {
  display: flex; align-items: center; justify-content: center; gap: 8px; flex-wrap: wrap;
  margin-top: 34px; text-align: center; color: var(--ink-soft); font-size: 14px;
  background: var(--teal-light); border: 1px dashed var(--teal); border-radius: var(--radius-sm);
  padding: 14px 18px; max-width: 760px; margin-left: auto; margin-right: auto;
}
.dl-safe svg { color: var(--teal-dark); flex: none; }

/* ---------- 教程步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; counter-reset: step; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 34px 28px; box-shadow: var(--shadow-sm); position: relative; }
.step-no {
  width: 52px; height: 52px; border-radius: 50%; background: var(--grad-brand); color: #fff;
  font-size: 24px; font-weight: 900; display: grid; place-items: center; margin-bottom: 18px;
  box-shadow: 0 8px 18px rgba(53, 198, 190, .4);
}
.step h3 { font-size: 19px; font-weight: 800; margin-bottom: 8px; }
.step p { color: var(--ink-soft); font-size: 15px; }

/* ---------- 客服 ---------- */
.service { background: linear-gradient(135deg, #1f2a37 0%, #26384a 100%); color: #fff; }
.service .section-head h2 { color: #fff; }
.service .section-head p { color: rgba(255, 255, 255, .78); }
.service-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 26px; max-width: 760px; margin: 0 auto; }
.service-card {
  background: rgba(255, 255, 255, .06); border: 1px solid rgba(255, 255, 255, .16);
  border-radius: var(--radius); padding: 30px 28px; text-align: center; backdrop-filter: blur(6px);
  transition: transform .22s, border-color .22s;
}
.service-card:hover { transform: translateY(-6px); border-color: var(--teal); }
.s-tag { font-size: 14px; color: var(--teal); font-weight: 700; letter-spacing: 1px; margin-bottom: 8px; }
.s-id { font-size: clamp(26px, 4vw, 34px); font-weight: 900; letter-spacing: 1px; margin-bottom: 20px; font-family: "Consolas", "Menlo", monospace; }
.service-tip { text-align: center; margin-top: 26px; color: rgba(255, 255, 255, .7); font-size: 14px; }

/* ---------- FAQ ---------- */
.faq-list { display: flex; flex-direction: column; gap: 14px; }
.faq-item { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-sm); overflow: hidden; transition: box-shadow .2s; }
.faq-item[open] { box-shadow: var(--shadow-sm); }
.faq-item summary {
  cursor: pointer; padding: 18px 22px; font-weight: 700; font-size: 16.5px; list-style: none;
  display: flex; align-items: center; justify-content: space-between;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; font-size: 22px; color: var(--teal-dark); font-weight: 700; transition: transform .2s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 0 22px 20px; color: var(--ink-soft); font-size: 15px; }
.faq-item b { color: var(--coral-dark); }

/* ---------- 页脚 ---------- */
.site-footer { background: #16212c; color: rgba(255, 255, 255, .72); padding: 52px 0 30px; }
.footer-inner { text-align: center; display: flex; flex-direction: column; align-items: center; gap: 20px; }
.footer-brand { display: flex; align-items: center; gap: 14px; }
.footer-brand img { border-radius: 12px; }
.f-name { font-size: 22px; font-weight: 900; color: #fff; text-align: left; }
.f-slogan { font-size: 13.5px; text-align: left; color: rgba(255, 255, 255, .6); }
.footer-nav { display: flex; flex-wrap: wrap; gap: 24px; justify-content: center; }
.footer-nav a { color: rgba(255, 255, 255, .78); font-weight: 600; font-size: 15px; transition: color .18s; }
.footer-nav a:hover { color: var(--teal); }
.footer-disclaimer { font-size: 13px; color: rgba(255, 255, 255, .5); max-width: 640px; }
.copyright { font-size: 13px; color: rgba(255, 255, 255, .45); border-top: 1px solid rgba(255, 255, 255, .1); padding-top: 20px; width: 100%; }

/* ---------- 悬浮下载 ---------- */
.float-dl {
  position: fixed; right: 18px; bottom: calc(18px + env(safe-area-inset-bottom)); z-index: 90; display: none;
  background: var(--grad-brand); color: #fff; font-weight: 800; padding: 14px 24px; border-radius: 999px;
  box-shadow: 0 12px 26px rgba(240, 85, 77, .42); animation: pulse 2.2s infinite;
}
@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: calc(40px + env(safe-area-inset-bottom)); transform: translateX(-50%) translateY(20px);
  background: rgba(31, 42, 55, .95); color: #fff; padding: 13px 26px; border-radius: 999px;
  font-size: 15px; font-weight: 600; opacity: 0; pointer-events: none; z-index: 200;
  transition: opacity .28s ease, transform .28s ease; box-shadow: var(--shadow-lg);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; padding: 52px 20px 40px; gap: 20px; }
  .hero-text .lead, .hero-note { margin-left: auto; margin-right: auto; }
  .hero-actions { justify-content: center; }
  .hero-visual { height: 420px; margin-top: 8px; }
  .phone { width: 200px; }
  .phone-back { transform: rotate(-8deg) translate(-52px, 6px); height: 400px; }
  .phone-front { transform: rotate(6deg) translate(52px, -4px); height: 410px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 760px) {
  .main-nav, .nav-cta { display: none; }
  .nav-toggle { display: flex; }
  .mobile-menu.open { display: flex; }
  .section { padding: 56px 0; }
  .trust-grid { grid-template-columns: repeat(2, 1fr); gap: 22px 12px; }
  .dl-grid, .shots-grid, .service-grid, .steps { grid-template-columns: 1fr; }
  .shots-grid { gap: 40px; }
  .step p { margin-bottom: 0; }
  .float-dl { display: inline-flex; }
  .hero-actions .btn { flex: 1 1 100%; }
}

@media (max-width: 460px) {
  .feature-grid { grid-template-columns: 1fr; }
  .brand-name { font-size: 18px; }
  .hero-visual { height: 360px; }
  .phone { width: 172px; }
  .phone-back { transform: rotate(-8deg) translate(-42px, 4px); height: 350px; }
  .phone-front { transform: rotate(6deg) translate(42px, -4px); height: 358px; }
  .t-num { font-size: 21px; }
}

/* 无障碍：尊重减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto !important; transition: none !important; }
}