/* ==========================================================================
   WhatsApp 网页版 · 站点样式表
   纯本地资源，无任何第三方依赖
   ========================================================================== */

:root {
  --green: #25d366;
  --green-d: #17a94f;
  --deep: #08382b;
  --teal: #128c7e;
  --ink: #0f211c;
  --muted: #596d65;
  --line: #e3ebe6;
  --bg: #f6faf7;
  --card: #ffffff;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgba(8, 56, 43, .05), 0 14px 34px -16px rgba(8, 56, 43, .22);
  --max: 1140px;
  --nav-h: 68px;
}

*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img,
svg { display: block; max-width: 100%; }

/* 锚点跳转时避开吸顶导航 */
[id] { scroll-margin-top: calc(var(--nav-h) + 18px); }

a {
  color: var(--teal);
  text-decoration: none;
}

a:hover { color: var(--deep); }

h1, h2, h3, h4 {
  margin: 0 0 .6em;
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--deep);
}

h1 {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  font-weight: 800;
  text-wrap: balance;
}
h2 { font-size: clamp(1.35rem, 2.2vw, 1.85rem); font-weight: 750; }
h3 { font-size: 1.12rem; font-weight: 700; }
h4 { font-size: 1rem; font-weight: 700; }

p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.25em; }
li { margin-bottom: .4em; }

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--deep);
  color: #fff;
  padding: 10px 16px;
  z-index: 999;
}

.skip:focus { left: 8px; top: 8px; }

/* ---------- 顶部导航 ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  height: var(--nav-h);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 800;
  font-size: 1.02rem;
  color: var(--deep);
  letter-spacing: -.02em;
  white-space: nowrap;
}

.logo svg { width: 30px; height: 30px; }

.logo b { color: var(--teal); font-weight: 800; }

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav a {
  display: block;
  padding: 7px 11px;
  border-radius: 999px;
  font-size: .925rem;
  color: #35504a;
  font-weight: 500;
  transition: background .18s, color .18s;
}

.nav a:hover { background: #eef7f1; color: var(--deep); }

.nav a[aria-current="page"] {
  background: #e6f7ec;
  color: var(--deep);
  font-weight: 700;
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 18px;
  border-radius: 999px;
  background: var(--deep);
  color: #fff;
  font-size: .9rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background .2s, transform .2s;
}

.header-cta:hover { background: var(--teal); color: #fff; transform: translateY(-1px); }

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 10px;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: var(--deep);
  border-radius: 2px;
  transition: transform .2s, opacity .2s;
}

/* ---------- 通用按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-size: .97rem;
  font-weight: 700;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .18s, box-shadow .18s, background .18s, color .18s;
}

.btn-primary {
  background: var(--green);
  color: #05321f;
  box-shadow: 0 10px 24px -10px rgba(37, 211, 102, .75);
}

.btn-primary:hover {
  background: var(--green-d);
  color: #fff;
  transform: translateY(-2px);
}

.btn-ghost {
  background: #fff;
  color: var(--deep);
  border-color: #cfe0d6;
}

.btn-ghost:hover { border-color: var(--teal); color: var(--teal); }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding: 64px 0 72px;
  background:
    radial-gradient(60% 80% at 88% 0%, #dff6e6 0%, rgba(223, 246, 230, 0) 62%),
    radial-gradient(50% 60% at 0% 100%, #e8f6f0 0%, rgba(232, 246, 240, 0) 60%),
    #fff;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr .92fr;
  gap: 48px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  margin-bottom: 18px;
  border-radius: 999px;
  background: #e6f7ec;
  color: #0b5c3b;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .02em;
}

.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(37, 211, 102, .25);
}

.hero h1 { margin-bottom: .5em; }

.hero h1 em {
  font-style: normal;
  background: linear-gradient(180deg, transparent 62%, #b8f0cd 62%);
  padding: 0 2px;
}

.hero-lead {
  font-size: 1.06rem;
  color: var(--muted);
  max-width: 34em;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 22px 0 30px;
  padding: 0;
  list-style: none;
  font-size: .92rem;
  color: #24443b;
}

.hero-points li {
  display: flex;
  align-items: center;
  gap: 7px;
  margin: 0;
}

.hero-points li::before {
  content: "";
  flex: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #d6f5e1 url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath d='M11.3 5.5 6.9 10 4.7 7.9' fill='none' stroke='%2317a94f' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 16px no-repeat;
}

/* 设备示意图（纯 CSS 绘制） */

.device-wrap { position: relative; }

.device {
  position: relative;
  width: 100%;
  max-width: 330px;
  margin: 0 auto;
  padding: 12px;
  background: #0b2f25;
  border-radius: 34px;
  box-shadow: 0 30px 60px -28px rgba(8, 56, 43, .55), 0 0 0 1px rgba(255, 255, 255, .06) inset;
}

.device-screen {
  background: #eef2ec url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='40' height='40' viewBox='0 0 40 40'%3E%3Cg fill='none' stroke='%23dfe7dd' stroke-width='1'%3E%3Cpath d='M0 20h40M20 0v40'/%3E%3C/g%3E%3C/svg%3E");
  border-radius: 24px;
  padding: 16px 12px 20px;
  min-height: 358px;
}

.device-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 4px 12px;
  border-bottom: 1px solid #dfe7dd;
}

.device-dot {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: linear-gradient(140deg, var(--green), var(--teal));
  flex: none;
}

.device-bar b {
  font-size: .78rem;
  color: #2c473f;
  display: block;
  line-height: 1.3;
}

.device-bar span {
  font-size: .68rem;
  color: #6d8a7d;
  display: block;
  line-height: 1.3;
}

.chat { padding-top: 14px; }

.bub {
  max-width: 84%;
  padding: 9px 13px;
  margin-bottom: 10px;
  border-radius: 14px;
  font-size: .8rem;
  line-height: 1.55;
  color: #1b2f28;
  background: #fff;
  box-shadow: 0 1px 1px rgba(11, 40, 30, .08);
  opacity: 0;
  transform: translateY(8px);
  animation: rise .5s ease forwards;
}

.bub-in { border-top-left-radius: 4px; }

.bub-out {
  margin-left: auto;
  background: #d9fdd3;
  border-top-right-radius: 4px;
  text-align: right;
}

.bub-file {
  background: #d9fdd3;
  margin-left: auto;
  font-size: .76rem;
  text-align: right;
}

.bub:nth-child(1) { animation-delay: .1s; }
.bub:nth-child(2) { animation-delay: .28s; }
.bub:nth-child(3) { animation-delay: .46s; }
.bub:nth-child(4) { animation-delay: .64s; }
.bub:nth-child(5) { animation-delay: .82s; }

@keyframes rise {
  to { opacity: 1; transform: translateY(0); }
}

.device-tag {
  position: absolute;
  right: -6px;
  bottom: 26px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 9px 13px;
  font-size: .74rem;
  font-weight: 700;
  color: var(--deep);
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: 7px;
}

.device-tag i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(37, 211, 102, .22);
  display: block;
}

/* ---------- 区块 ---------- */

.section { padding: 66px 0; }
.section.alt { background: #fff; border-block: 1px solid var(--line); }
.section.tight { padding: 48px 0; }

.section-head { max-width: 720px; margin-bottom: 38px; }
.section-head p { color: var(--muted); margin-bottom: 0; }

.overline {
  display: block;
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--teal);
  margin-bottom: 10px;
}

.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: #cfe3d8;
}

.card h3 { margin-bottom: .45em; }
.card p { margin-bottom: 0; color: var(--muted); font-size: .94rem; }

.card .ico {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: #e9f8ef;
  margin-bottom: 16px;
  color: var(--teal);
}

.card .ico svg { width: 22px; height: 22px; }

/* 步骤 */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  counter-reset: step;
  padding: 0;
  list-style: none;
  margin: 0;
}

.steps li {
  position: relative;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px 24px;
  margin: 0;
  counter-increment: step;
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  display: inline-block;
  font-size: .78rem;
  font-weight: 800;
  color: var(--teal);
  letter-spacing: .06em;
  margin-bottom: 10px;
}

.steps h3 { font-size: 1.02rem; margin-bottom: .4em; }
.steps p { margin: 0; font-size: .93rem; color: var(--muted); }

/* 表格 */
.table-wrap { overflow-x: auto; margin: 0 0 1.4em; }

table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  font-size: .93rem;
}

th, td {
  padding: 13px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  background: #f2f8f4;
  font-weight: 700;
  color: var(--deep);
  white-space: nowrap;
}

tbody tr:last-child td { border-bottom: 0; }

/* ---------- 内页头部 ---------- */

.page-head {
  background:
    radial-gradient(70% 120% at 100% 0%, #e2f7e9 0%, rgba(226, 247, 233, 0) 60%),
    #fff;
  border-bottom: 1px solid var(--line);
  padding: 46px 0 50px;
}

.page-head h1 { max-width: 22em; }

.page-head .lead {
  max-width: 46em;
  color: var(--muted);
  font-size: 1.03rem;
  margin-bottom: 0;
}

.crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: .82rem;
  color: #7c918a;
  margin-bottom: 14px;
  padding: 0;
  list-style: none;
}

.crumb li { margin: 0; display: flex; align-items: center; gap: 6px; }
.crumb li + li::before { content: "/"; color: #c3d3ca; }
.crumb a { color: #5b7a70; }
.crumb a:hover { color: var(--teal); }

/* ---------- 正文排版 ---------- */

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 48px;
  align-items: start;
}

.prose { max-width: 100%; }
.prose h2 { margin-top: 2.2em; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { margin-top: 1.7em; }
.prose p, .prose li { color: #2c4340; }
.prose strong { color: var(--deep); }

.prose table { margin-top: 1.2em; }

.note {
  border-left: 3px solid var(--green);
  background: #f1fbf4;
  border-radius: 0 12px 12px 0;
  padding: 16px 20px;
  margin: 1.6em 0;
  font-size: .94rem;
  color: #24443b;
}

.note strong { color: var(--deep); }

.checklist {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 10px;
  margin: 1.2em 0 1.6em;
}

.checklist li {
  position: relative;
  padding-left: 30px;
  margin: 0;
  font-size: .95rem;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 19px;
  height: 19px;
  border-radius: 50%;
  background: #dff6e7 url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='19' height='19' viewBox='0 0 19 19'%3E%3Cpath d='M13 7 8.2 11.8 6 9.6' fill='none' stroke='%2317a94f' stroke-width='1.9' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 13px no-repeat;
}

/* 侧栏 */
.side { position: sticky; top: calc(var(--nav-h) + 20px); display: grid; gap: 16px; }

.side-box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

.side-box h3,
.side-box .side-title {
  font-size: .82rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: #83998f;
  font-weight: 800;
  margin-bottom: 12px;
}

.side-nav { list-style: none; padding: 0; margin: 0; display: grid; gap: 2px; }
.side-nav li { margin: 0; }

.side-nav a {
  display: block;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: .9rem;
  color: #3a554c;
}

.side-nav a:hover { background: #f1f9f4; color: var(--deep); }

.side-cta {
  background: linear-gradient(160deg, #0a3d2e, #12604a);
  border: 0;
  color: #d6f5e3;
}

.side-cta h3 {
  color: #fff;
  font-size: 1.02rem;
  letter-spacing: 0;
  text-transform: none;
  margin-bottom: 8px;
}

.side-cta p { font-size: .89rem; color: #b6dbc9; margin-bottom: 16px; }

.side-cta .btn {
  width: 100%;
  padding: 11px 16px;
  font-size: .9rem;
}

/* ---------- FAQ ---------- */

.faq {
  display: grid;
  gap: 10px;
}

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0 20px;
  transition: border-color .2s, box-shadow .2s;
}

.faq details[open] {
  border-color: #c6e6d4;
  box-shadow: 0 12px 28px -18px rgba(8, 56, 43, .35);
}

.faq summary {
  cursor: pointer;
  padding: 16px 34px 16px 0;
  font-weight: 700;
  font-size: .98rem;
  color: var(--deep);
  position: relative;
  list-style: none;
}

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

.faq summary::after {
  content: "";
  position: absolute;
  right: 0;
  top: 50%;
  width: 11px;
  height: 11px;
  margin-top: -7px;
  border-right: 2px solid var(--teal);
  border-bottom: 2px solid var(--teal);
  transform: rotate(45deg);
  transition: transform .2s;
}

.faq details[open] summary::after { transform: rotate(-135deg); margin-top: -2px; }

.faq .a {
  padding: 0 0 18px;
  font-size: .94rem;
  color: #334c46;
  border-top: 1px dashed var(--line);
  padding-top: 14px;
}

.faq .a p:last-child { margin-bottom: 0; }

/* ---------- 相关链接卡 ---------- */

.link-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  padding: 0;
  list-style: none;
  margin: 0;
}

.link-cards li { margin: 0; }

.link-cards a {
  display: block;
  height: 100%;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px;
  color: var(--deep);
  font-weight: 700;
  font-size: .96rem;
  transition: border-color .2s, transform .2s, box-shadow .2s;
}

.link-cards a span {
  display: block;
  font-weight: 400;
  font-size: .86rem;
  color: var(--muted);
  margin-top: 5px;
  line-height: 1.6;
}

.link-cards a:hover {
  border-color: var(--green);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

/* ---------- CTA 条 ---------- */

.cta-band {
  background: linear-gradient(120deg, #08382b 0%, #0e5340 55%, #10705a 100%);
  border-radius: 22px;
  padding: 46px 44px;
  color: #d8f2e4;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 26px;
}

.cta-band h2 { color: #fff; margin-bottom: .35em; }
.cta-band p { margin: 0; color: #b5dcc9; max-width: 40em; }

.cta-band .btn-primary { box-shadow: none; }

/* ---------- 页脚 ---------- */

.site-footer {
  background: #072a21;
  color: #9dc0b1;
  padding: 56px 0 28px;
  margin-top: 66px;
  font-size: .9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 36px;
  padding-bottom: 34px;
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}

.site-footer .logo { color: #fff; }
.site-footer .logo b { color: var(--green); }

.site-footer p { color: #8fb2a4; margin: 14px 0 0; max-width: 26em; }

.footer-col h4 {
  color: #fff;
  font-size: .86rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.footer-col ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 9px; }
.footer-col li { margin: 0; }
.footer-col a { color: #9dc0b1; font-size: .89rem; }
.footer-col a:hover { color: #fff; }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
  padding-top: 22px;
  font-size: .82rem;
  color: #7c9d90;
}

/* ---------- 返回顶部 ---------- */

.to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 0;
  background: var(--deep);
  color: #fff;
  cursor: pointer;
  display: grid;
  place-items: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity .25s, transform .25s, visibility .25s;
  box-shadow: var(--shadow);
  z-index: 40;
}

.to-top.show { opacity: 1; visibility: visible; transform: none; }

/* ---------- 入场动效 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .55s ease, transform .55s ease;
}

.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .bub { animation: none; opacity: 1; transform: none; }
  .card:hover, .link-cards a:hover { transform: none; }
}

/* ---------- 响应式 ---------- */

@media (max-width: 1000px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .device-wrap { order: 2; max-width: 360px; margin: 0 auto; }
  .layout { grid-template-columns: 1fr; gap: 34px; }
  .side { position: static; grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 820px) {
  .nav {
    position: absolute;
    top: var(--nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 10px 16px 16px;
    display: none;
    box-shadow: 0 18px 30px -22px rgba(8, 56, 43, .35);
  }

  .nav.open { display: flex; }
  .nav a { padding: 11px 12px; border-radius: 8px; font-size: .96rem; }
  .header-cta { display: none; }
  .nav-toggle { display: block; }

  .grid-3, .grid-2, .steps { grid-template-columns: 1fr; }
  .section { padding: 50px 0; }
  .hero { padding: 44px 0 54px; }
  .page-head { padding: 34px 0 38px; }
  .cta-band { padding: 32px 24px; }
  .side { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  h1 { font-size: 1.52rem; }
  .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .btn { width: 100%; }
  .btn-row { flex-direction: column; }
  th, td { padding: 11px 12px; font-size: .88rem; }
}