/* ============================================================
   腾龙App 官网 · 公共样式 V3
   风格:暗暖大地色(Dark Earth)· 深焙咖啡底 · 奶油文字 · 移动端优先
   ============================================================ */

:root {
  --bg:      #232019;  /* 页面底色 · 深焙咖啡 */
  --bg-2:    #2b271f;  /* 分区底色 · 烤褐 */
  --card:    #322d24;  /* 卡片 */
  --ink:     #efe7d8;  /* 主文字 · 奶油 */
  --muted:   #a89e8a;  /* 次文字 · 浅驼 */
  --line:    #403a2f;  /* 分隔线 */
  --clay:    #cf7a4e;  /* 陶土橘(主强调) */
  --clay-d:  #b8613a;
  --sage:    #93a67d;  /* 灰绿(副强调) */

  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans:  "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;

  --ease: cubic-bezier(.16, 1, .3, 1);
  --pill: 999px;
  --r-lg: 20px;
  --bar-h: 74px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.8;
  font-size: 16px;
  padding-bottom: calc(var(--bar-h) + 18px);
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 2px solid var(--clay); outline-offset: 2px; }

/* ---------- 排版 ---------- */
h1, h2, h3 { font-family: var(--serif); font-weight: 700; line-height: 1.28; text-wrap: balance; }
h1 { font-size: clamp(2.05rem, 7vw, 3.5rem); letter-spacing: .015em; }
h2 { font-size: clamp(1.5rem, 5vw, 2.3rem); letter-spacing: .015em; }
h3 { font-size: 1.18rem; }
p  { max-width: 65ch; }
strong, b { color: var(--ink); }

.wrap { max-width: 1060px; margin: 0 auto; padding: 0 22px; }

/* 眉标:细线 + 小字,克制不抢戏 */
.kicker {
  display: flex; align-items: center; gap: 10px;
  font-size: .8rem; letter-spacing: .22em;
  color: var(--sage); margin-bottom: 18px;
}
.kicker::before { content: ""; width: 26px; height: 1px; background: var(--sage); opacity: .7; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky; top: 10px; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1020px; margin: 10px auto 0;
  padding: 10px 10px 10px 24px;
  background: rgba(43, 39, 31, .88);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: var(--pill);
}
.nav .logo { font-family: var(--serif); font-weight: 700; font-size: 1.18rem; letter-spacing: .03em; display: flex; align-items: center; gap: 9px; }
.nav .logo img {
  width: 34px; height: 34px; border-radius: 9px;
  background: #fff; object-fit: cover;
  box-shadow: 0 2px 8px rgba(0,0,0,.35);
}
.nav .logo em { font-style: normal; color: var(--clay); }
.nav-links { display: flex; gap: 4px; align-items: center; font-size: .9rem; }
.nav-links a { color: var(--muted); padding: 9px 14px; border-radius: var(--pill); transition: color .18s var(--ease), background .18s var(--ease); }
.nav-links a:hover, .nav-links a[aria-current] { color: var(--ink); }
.nav .login-link { color: var(--ink); background: rgba(147,166,125,.16); }
.nav .login-link:hover { background: rgba(147,166,125,.28); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block; text-align: center;
  padding: 15px 36px; font-size: 1rem; letter-spacing: .04em;
  border-radius: var(--pill); border: none; cursor: pointer;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), background .18s var(--ease);
}
.btn:active { transform: scale(.97); }
.btn-clay  { background: var(--clay); color: #1f1a14; font-weight: 600; box-shadow: 0 10px 28px rgba(207,122,78,.22); }
.btn-clay:hover { background: #dd8a5d; }
.btn-sage  { background: var(--sage); color: #1f1a14; font-weight: 600; box-shadow: 0 10px 28px rgba(147,166,125,.18); }
.btn-sage:hover { background: #a3b58d; }
.btn-ghost { background: transparent; color: var(--ink); border: 1.5px solid var(--line); }
.btn-ghost:hover { border-color: var(--muted); }

/* ---------- Hero ---------- */
.hero { padding: 84px 0 68px; position: relative; overflow: hidden; }
.hero::before, .hero::after { content: ""; position: absolute; border-radius: 50%; z-index: -1; filter: blur(10px); }
.hero::before {
  width: 460px; height: 460px; right: -140px; top: -160px;
  background: radial-gradient(circle, rgba(207,122,78,.14), transparent 68%);
}
.hero::after {
  width: 420px; height: 420px; left: -160px; bottom: -180px;
  background: radial-gradient(circle, rgba(147,166,125,.12), transparent 68%);
}
.hero .grid { display: grid; gap: 48px; align-items: center; }
.hero h1 .accent { color: var(--clay); }
.hero .lede { color: var(--muted); font-size: 1.02rem; margin: 20px 0 34px; max-width: 40ch; }
.hero .cta-row { display: flex; gap: 14px; flex-wrap: wrap; }

/* 手机模型:深色机身 + 简化屏内元素 */
.phone {
  width: min(240px, 62vw); margin: 0 auto;
  aspect-ratio: 9 / 19;
  border: 9px solid #171410; border-radius: 40px;
  background: #171410;
  position: relative;
  box-shadow: 0 30px 60px rgba(0,0,0,.45), 0 0 0 1px var(--line);
}
.phone::before {
  content: ""; position: absolute; top: 7px; left: 50%;
  transform: translateX(-50%);
  width: 54px; height: 5px; border-radius: 3px;
  background: #4a443a;
}
.phone .screen {
  position: absolute; inset: 2px;
  background: var(--bg-2); border-radius: 30px;
  padding: 26px 15px 15px;
  overflow: hidden;
}
.phone .screen b {
  display: block; color: var(--ink); font-size: .82rem;
  margin-bottom: 14px; font-family: var(--serif); letter-spacing: .1em;
}
.phone .screen i {
  display: block; height: 9px; border-radius: 5px; background: var(--line);
  margin-bottom: 10px; font-style: normal;
}
.phone .screen i.tall { height: 56px; border-radius: 14px; }
.phone .screen i.sage { background: rgba(147,166,125,.38); }
.phone .screen i.clay { background: rgba(207,122,78,.45); }

/* ---------- 分区 ---------- */
.section { padding: 76px 0; }
.section.soft { background: var(--bg-2); }
.section-head { margin-bottom: 42px; }

/* 特性卡片:统一对齐,顶部色线做区分 */
.feature-cards { display: grid; gap: 18px; }
.f-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 30px 26px;
  position: relative; overflow: hidden;
}
.f-card::before { content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--sage); opacity: .8; }
.f-card:nth-child(2)::before { background: var(--clay); }
.f-card:nth-child(3)::before { background: var(--muted); }
.f-card .dot {
  width: 42px; height: 42px; border-radius: 12px;
  display: grid; place-items: center;
  font-family: var(--serif); font-size: 1.1rem; color: var(--bg);
  background: var(--sage); margin-bottom: 16px;
}
.f-card:nth-child(2) .dot { background: var(--clay); }
.f-card:nth-child(3) .dot { background: var(--muted); }
.f-card h3 { margin-bottom: 8px; }
.f-card p { color: var(--muted); font-size: .93rem; line-height: 1.75; }

/* 图文带 */
.split { display: grid; gap: 36px; align-items: center; }
.split .panel {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--r-lg); padding: 22px;
}
.split h2 { margin-bottom: 10px; }
.split .caption { color: var(--muted); font-size: .95rem; }

/* 下载引导带 */
.download-band { text-align: center; padding: 84px 0; }
.download-band .kicker { justify-content: center; }
.download-band .kicker::after { content: ""; width: 26px; height: 1px; background: var(--sage); opacity: .7; }
.download-band p { color: var(--muted); margin: 16px auto 34px; }

/* ---------- ★ 移动端底部悬浮操作栏 ---------- */
.bottom-cta {
  position: fixed; left: 50%; transform: translateX(-50%);
  bottom: calc(10px + env(safe-area-inset-bottom)); z-index: 100;
  display: flex; gap: 8px;
  width: min(520px, calc(100% - 24px));
  padding: 7px;
  background: rgba(35, 32, 25, .94);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--pill);
  box-shadow: 0 14px 40px rgba(0,0,0,.5);
}
.bottom-cta a {
  display: flex; align-items: center; justify-content: center;
  height: 48px; font-size: .92rem; border-radius: var(--pill);
  letter-spacing: .05em;
}
.bottom-cta .bc-dl      { background: var(--clay); color: #1f1a14; font-weight: 600; flex: 1.6; }
.bottom-cta .bc-contact { background: transparent; color: var(--ink); border: 1px solid var(--line); flex: 1.3; }
.bottom-cta .bc-login   { background: rgba(147,166,125,.18); color: var(--sage); border: 1px solid rgba(147,166,125,.35); flex: 1; }
@media (min-width: 721px) {
  .bottom-cta { display: none; }
  body { padding-bottom: 0; }
}

/* ---------- FAQ ---------- */
.faq { max-width: 760px; }
.faq dt { font-family: var(--serif); font-weight: 700; font-size: 1.05rem; padding: 20px 0 8px; }
.faq dd { color: var(--muted); font-size: .95rem; padding-bottom: 20px; border-bottom: 1px solid var(--line); }
.faq a { color: var(--clay); border-bottom: 1px solid rgba(207,122,78,.4); }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--line); padding: 48px 0 32px; color: var(--muted); font-size: .85rem; }
.footer .cols { display: grid; gap: 26px; margin-bottom: 34px; }
.footer h4 { font-family: var(--serif); color: var(--ink); font-size: .95rem; margin-bottom: 10px; letter-spacing: .05em; }
.footer a { display: block; padding: 3px 0; }
.footer a:hover { color: var(--clay); }
.footer .icp { text-align: center; font-size: .8rem; }
.footer .icp a { display: inline; }

/* ---------- 表单 ---------- */
.form { max-width: 430px; }
.form label { display: block; margin: 20px 0 7px; font-size: .88rem; color: var(--muted); letter-spacing: .04em; }
.form input, .form textarea, .form select {
  width: 100%; padding: 14px 18px; font-size: 1rem; font-family: var(--sans);
  background: var(--card); color: var(--ink);
  border: 1.5px solid var(--line); border-radius: var(--pill);
  transition: border-color .18s var(--ease);
}
.form textarea { border-radius: 18px; }
.form input::placeholder, .form textarea::placeholder { color: #7a7263; }
.form input:focus, .form textarea:focus, .form select:focus { border-color: var(--sage); outline: none; }
.form .btn { width: 100%; margin-top: 28px; }
.form .hint { font-size: .8rem; color: var(--muted); margin-top: 12px; }
.form .hint a { color: var(--clay); }
.form .error { color: #e0876b; font-size: .85rem; margin-top: 6px; display: none; }
.form .error.show { display: block; }
.form .agree { display: flex; gap: 8px; align-items: flex-start; font-size: .8rem; color: var(--muted); margin-top: 16px; max-width: 65ch; }
.form .agree input { width: auto; margin-top: 4px; }
.form .agree a { color: var(--sage); }
.code-row { display: flex; gap: 10px; }
.code-row input { flex: 1; }
.code-row .btn { flex: 0 0 auto; width: auto; margin-top: 0; padding: 0 20px; font-size: .9rem; }

/* 联系方式卡片 */
.contact-cards { display: grid; gap: 16px; }
.c-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--r-lg); padding: 28px 26px;
}
.c-card h3 { margin-bottom: 6px; }
.c-card p { color: var(--muted); font-size: .93rem; }
.c-card a.big {
  display: inline-block; margin-top: 12px;
  font-family: var(--serif); font-size: 1.3rem; color: var(--clay);
  letter-spacing: .02em;
}
.c-card .sub { font-size: .8rem; color: #7a7263; margin-top: 10px; }
.c-card img.qr {
  width: 190px; max-width: 100%; margin: 14px auto 0;
  border-radius: 14px; background: #fff; padding: 6px;
  box-shadow: 0 6px 18px rgba(0,0,0,.3);
}
.c-card .acct {
  display: inline-block; margin-top: 10px; padding: 4px 14px;
  font-size: .9rem; color: var(--ink);
  background: var(--bg-2); border: 1px dashed var(--line); border-radius: var(--pill);
  user-select: all;  /* 长按/双击可整段复制账号 */
}

/* 界面预览:手机端横滑,桌面端三列 */
.shots { display: flex; gap: 14px; overflow-x: auto; padding-bottom: 10px; scroll-snap-type: x mandatory; -webkit-overflow-scrolling: touch; }
.shots::-webkit-scrollbar { display: none; }
.shots figure { flex: 0 0 46%; scroll-snap-align: start; margin: 0; }
.shot {
  aspect-ratio: 9 / 18; border-radius: 20px; overflow: hidden;
  border: 1px solid var(--line); background: var(--card);
}
.shot img { width: 100%; height: 100%; object-fit: cover; display: block; }
/* 图片占位框:没放图时显示,放了图自动被真实图片顶掉 */
.shot-ph {
  height: 100%; display: grid; place-items: center; text-align: center;
  color: var(--muted); font-size: .78rem; line-height: 1.9;
  border: 1.5px dashed var(--line); border-radius: 20px; padding: 12px;
}
.shot-ph b { color: var(--clay); font-family: var(--serif); font-size: .9rem; }
.split .panel .shot-ph { aspect-ratio: 16 / 10; }

/* 首页手机模型内的全屏截图位:有图盖满,无图显示内置模拟界面 */
.phone .screen img.fill {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover;
  border-radius: 30px;
}

/* ---------- 首页背景图(仅首页 body.home 生效) ----------
   上传 img/bg.jpg 自动启用;没有该文件时回落纯色,不破相 */
body.home { background-color: var(--bg); }
/* 背景层:照片模糊压暗 + 上半透明深咖遮罩,固定铺满屏幕,文字永远清晰 */
body.home::before {
  content: ""; position: fixed; inset: -12px; z-index: -1;
  background-image:
    linear-gradient(rgba(35,32,25,.55), rgba(35,32,25,.72) 40%, rgba(35,32,25,.62)),
    url("img/bg.jpg");
  background-size: cover;
  background-position: center;
  filter: blur(4px);
}
/* 背景图上,首页各分区改为半透明,让图透出来 */
.home .section.soft { background: rgba(43,39,31,.58); }
.home .nav { background: rgba(35,32,25,.68); }
.home .footer { background: rgba(35,32,25,.66); }
.home .bottom-cta { background: rgba(35,32,25,.82); }
.home .f-card, .home .shot { background: rgba(50,45,36,.78); }

/* ---------- 入场动画 ---------- */
@keyframes rise { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: none; } }
.hero .grid > * { animation: rise .7s var(--ease) both; }
.hero .grid > *:nth-child(2) { animation-delay: .15s; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

/* ---------- 响应式 ---------- */
/* 手机端:按钮全部通栏,单列好按;导航只留 Logo+登录 */
@media (max-width: 720px) {
  .nav { padding: 9px 9px 9px 18px; }
  .nav-links a { display: none; }
  .nav-links a.login-link { display: inline-block; }
  .hero .cta-row { flex-direction: column; }
  .hero .cta-row .btn { width: 100%; }
}

@media (min-width: 721px) {
  .hero { padding: 120px 0 92px; }
  .hero .grid { grid-template-columns: 1.15fr .85fr; }
  .shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; overflow: visible; }
  .feature-cards { grid-template-columns: repeat(3, 1fr); }
  .split { grid-template-columns: 1fr 1fr; }
  .split .flip > *:first-child { order: 2; }
  .contact-cards { grid-template-columns: repeat(3, 1fr); }
  .footer .cols { grid-template-columns: repeat(4, 1fr); }
  .nav { margin-top: 18px; padding: 12px 12px 12px 28px; }
}