/* ==========================================================
   言讯 · 即时通讯官网
   新疆言讯网络科技有限公司
   ========================================================== */

:root {
  --brand: #1a56db;
  --brand-dark: #1443ad;
  --brand-soft: #eef3fd;

  --ink: #1f2328;
  --ink-2: #40474f;
  --muted: #6b7280;
  --line: #e3e6ea;
  --line-soft: #eef0f3;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;

  --radius: 8px;
  --maxw: 1120px;
  --header-h: 64px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, textarea { font-family: inherit; font-size: inherit; color: inherit; }

.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 排版 ---------- */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.35; letter-spacing: -.01em; }

.section { padding: 72px 0; }
.section--soft { background: var(--bg-soft); }
.section--line { border-top: 1px solid var(--line); }

.sec-head { margin-bottom: 40px; max-width: 720px; }
.sec-head h2 { font-size: 27px; margin-bottom: 10px; }
.sec-head p { color: var(--muted); font-size: 15px; }

.label {
  display: inline-block; font-size: 13px; font-weight: 600; color: var(--brand);
  letter-spacing: .02em; margin-bottom: 12px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 42px; padding: 0 22px; border-radius: 6px;
  font-size: 15px; font-weight: 500; border: 1px solid transparent;
  cursor: pointer; transition: background .18s, border-color .18s, color .18s;
  white-space: nowrap;
}
.btn--primary { background: var(--brand); color: #fff; }
.btn--primary:hover { background: var(--brand-dark); }
.btn--ghost { background: #fff; color: var(--ink); border-color: var(--line); }
.btn--ghost:hover { border-color: #c3c9d2; }
.btn--sm { height: 36px; padding: 0 16px; font-size: 14px; }

/* ---------- 导航 ---------- */
.header {
  position: fixed; inset: 0 0 auto 0; height: var(--header-h); z-index: 100;
  background: #fff; border-bottom: 1px solid var(--line);
}
.header.is-scrolled { box-shadow: 0 1px 4px rgba(0, 0, 0, .05); }
.header__inner { height: 100%; display: flex; align-items: center; gap: 32px; }

.logo { display: flex; align-items: center; gap: 9px; flex: none; }
.logo__mark {
  width: 30px; height: 30px; border-radius: 6px; flex: none;
  background: var(--brand); display: grid; place-items: center;
}
.logo__mark svg { width: 18px; height: 18px; }
.logo__cn { font-size: 18px; font-weight: 700; letter-spacing: .02em; }

.nav { display: flex; align-items: center; gap: 26px; margin-right: auto; }
.nav a { font-size: 15px; color: var(--ink-2); padding: 4px 0; border-bottom: 2px solid transparent; }
.nav a:hover { color: var(--ink); }
.nav a.is-active { color: var(--brand); border-bottom-color: var(--brand); font-weight: 500; }

.header__actions { display: flex; align-items: center; gap: 10px; flex: none; }

.burger {
  display: none; width: 38px; height: 38px; border: 1px solid var(--line);
  border-radius: 6px; background: #fff; cursor: pointer;
  flex-direction: column; align-items: center; justify-content: center;
}
.burger span { display: block; width: 16px; height: 1.5px; background: var(--ink); }
.burger span + span { margin-top: 4px; }
.burger.is-open span:nth-child(2) { opacity: 0; }

.mobile-nav {
  position: fixed; top: var(--header-h); left: 0; right: 0; z-index: 99;
  background: #fff; border-bottom: 1px solid var(--line); padding: 8px 24px 20px; display: none;
}
.mobile-nav.is-open { display: block; }
.mobile-nav a { display: block; padding: 12px 0; font-size: 15px; border-bottom: 1px solid var(--line-soft); }
.mobile-nav .btn { margin-top: 16px; width: 100%; }

/* ---------- Hero ---------- */
.hero {
  padding: calc(var(--header-h) + 64px) 0 64px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-soft);
}
.hero__grid { display: grid; grid-template-columns: 1fr 380px; gap: 56px; align-items: center; }
.hero h1 { font-size: 34px; line-height: 1.4; margin-bottom: 16px; }
.hero__desc { font-size: 16px; color: var(--ink-2); max-width: 560px; }
.hero__btns { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.hero__note { margin-top: 16px; font-size: 13.5px; color: var(--muted); }

/* 客户端窗口示意 */
.shot { border: 1px solid var(--line); border-radius: var(--radius); background: #fff; overflow: hidden; }
.shot__bar {
  display: flex; align-items: center; gap: 10px; padding: 10px 14px;
  background: #f2f4f7; border-bottom: 1px solid var(--line); font-size: 13px;
}
.shot__bar b { font-weight: 600; }
.shot__bar span { color: var(--muted); font-size: 12px; }
.shot__body { padding: 16px 14px; background: #fbfbfc; }
.msg { display: flex; gap: 8px; margin-bottom: 12px; }
.msg--me { flex-direction: row-reverse; }
.msg__ava {
  width: 28px; height: 28px; border-radius: 5px; flex: none; display: grid; place-items: center;
  font-size: 12px; font-weight: 600; background: #e6ecf8; color: var(--brand);
}
.msg--me .msg__ava { background: var(--brand); color: #fff; }
.msg__bubble {
  max-width: 78%; padding: 8px 12px; border-radius: 3px 10px 10px 10px;
  background: #fff; border: 1px solid var(--line); font-size: 13.5px; line-height: 1.6;
}
.msg--me .msg__bubble { background: var(--brand); color: #fff; border-color: var(--brand); border-radius: 10px 3px 10px 10px; }
.msg__bubble small { display: block; margin-top: 4px; font-size: 11px; opacity: .6; }
.msg__file { display: flex; align-items: center; gap: 8px; }
.msg__file i { width: 28px; height: 28px; border-radius: 5px; background: var(--brand-soft); display: grid; place-items: center; flex: none; }
.msg__file em { font-style: normal; font-weight: 600; font-size: 13px; display: block; }
.msg__file span { font-size: 11.5px; opacity: .65; }
.shot__foot { padding: 10px 14px; border-top: 1px solid var(--line); background: #fff; }
.shot__input {
  height: 32px; border: 1px solid var(--line); border-radius: 6px; background: var(--bg-soft);
  display: flex; align-items: center; padding: 0 10px; font-size: 12.5px; color: #9aa1ab;
}

/* ---------- 平台条 ---------- */
.platforms { padding: 20px 0; border-bottom: 1px solid var(--line); background: #fff; }
.platforms__row { display: flex; align-items: center; gap: 28px; flex-wrap: wrap; }
.platforms__label { font-size: 13.5px; color: var(--muted); }
.platforms__list { display: flex; align-items: center; gap: 24px; flex-wrap: wrap; }
.platforms__list span { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; color: var(--ink-2); }
.platforms__list svg { width: 17px; height: 17px; color: var(--muted); }

/* ---------- 卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card {
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px 22px; background: #fff; transition: border-color .18s;
}
.card:hover { border-color: #c3cddf; }
.card h3 { font-size: 16.5px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14px; }
.card__icon {
  width: 36px; height: 36px; border-radius: 6px; margin-bottom: 14px;
  background: var(--brand-soft); color: var(--brand); display: grid; place-items: center;
}
.card__icon svg { width: 19px; height: 19px; }
.card ul { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--line-soft); display: grid; gap: 6px; }
.card ul li { position: relative; padding-left: 14px; font-size: 13.5px; color: var(--ink-2); }
.card ul li::before { content: ""; position: absolute; left: 0; top: 9px; width: 4px; height: 4px; border-radius: 50%; background: #b6c2d6; }

/* ---------- 多端 ---------- */
.devices { display: grid; grid-template-columns: 260px 1fr; gap: 32px; align-items: start; }
.devices__tabs { display: grid; gap: 6px; }
.devices__tab {
  display: flex; align-items: center; gap: 10px; width: 100%; cursor: pointer; text-align: left;
  padding: 11px 14px; border-radius: 6px; border: 1px solid transparent; background: transparent;
  transition: background .18s, border-color .18s;
}
.devices__tab svg { width: 18px; height: 18px; color: var(--muted); flex: none; }
.devices__tab b { display: block; font-size: 14.5px; font-weight: 500; }
.devices__tab:hover { background: var(--bg-soft); }
.devices__tab.is-active { background: var(--brand-soft); border-color: #ccdaf5; }
.devices__tab.is-active svg, .devices__tab.is-active b { color: var(--brand); }

.devices__panel { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px 26px; background: #fff; }
.devices__pane { display: none; }
.devices__pane.is-active { display: block; }
.devices__pane h4 { font-size: 17px; margin-bottom: 6px; }
.devices__pane > p { color: var(--muted); font-size: 14.5px; margin-bottom: 20px; }

.kv { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.kv div { border: 1px solid var(--line-soft); border-radius: 6px; padding: 12px 14px; background: var(--bg-soft); }
.kv div em { display: block; font-style: normal; font-size: 12.5px; color: var(--muted); margin-bottom: 2px; }
.kv div b { font-size: 14px; font-weight: 600; }

/* ---------- 部署说明 ---------- */
.arch { border: 1px solid var(--line); border-radius: var(--radius); background: #fff; overflow: hidden; }
.arch__head { padding: 14px 22px; background: var(--bg-soft); border-bottom: 1px solid var(--line); font-weight: 600; font-size: 15px; }
.arch__table { width: 100%; border-collapse: collapse; font-size: 14px; }
.arch__table th, .arch__table td { text-align: left; padding: 13px 22px; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
.arch__table th { width: 150px; color: var(--muted); font-weight: 400; }
.arch__table tr:last-child th, .arch__table tr:last-child td { border-bottom: 0; }

/* ---------- 解决方案 ---------- */
.solutions { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.solu { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px 22px; background: #fff; transition: border-color .18s; }
.solu:hover { border-color: #c3cddf; }
.solu h3 { font-size: 16.5px; margin-bottom: 8px; }
.solu p { color: var(--muted); font-size: 14px; }

/* ---------- 表格型列表 ---------- */
.rows { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: #fff; }
.row { display: grid; grid-template-columns: 210px 1fr; gap: 20px; padding: 18px 22px; border-bottom: 1px solid var(--line-soft); }
.row:last-child { border-bottom: 0; }
.row__t { font-weight: 600; font-size: 14.5px; }
.row__t span { display: block; font-weight: 400; font-size: 12.5px; color: var(--muted); margin-top: 2px; }
.row p { color: var(--ink-2); font-size: 14px; }
.row ul { margin-top: 8px; display: grid; gap: 5px; }
.row ul li { position: relative; padding-left: 14px; font-size: 13.5px; color: var(--muted); }
.row ul li::before { content: ""; position: absolute; left: 0; top: 9px; width: 4px; height: 4px; border-radius: 50%; background: #b6c2d6; }

/* ---------- CTA ---------- */
.cta {
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg-soft);
  display: grid; grid-template-columns: 1fr 340px; gap: 40px; padding: 36px; align-items: center;
}
.cta h2 { font-size: 22px; margin-bottom: 8px; }
.cta p { color: var(--muted); font-size: 14.5px; }
.cta__form { display: grid; gap: 10px; }
.cta__form input, .cta__form textarea {
  width: 100%; border: 1px solid var(--line); border-radius: 6px; background: #fff;
  padding: 10px 12px; font-size: 14px; outline: none; transition: border-color .18s;
}
.cta__form input:focus, .cta__form textarea:focus { border-color: var(--brand); }
.cta__form textarea { resize: vertical; min-height: 76px; }
.cta__form .btn { width: 100%; }
.cta__tip { font-size: 12.5px; color: var(--muted); min-height: 18px; }

/* ---------- 页脚 ---------- */
.footer { background: #1c2024; color: #9aa2ad; padding: 48px 0 0; font-size: 13.5px; }
.footer__top { display: grid; grid-template-columns: 1.7fr repeat(3, 1fr); gap: 36px; padding-bottom: 36px; }
.footer__brand p { margin-top: 14px; max-width: 320px; line-height: 1.8; color: #8b939e; }
.footer .logo__cn { color: #fff; }
.footer h5 { color: #fff; font-size: 14px; font-weight: 600; margin-bottom: 14px; }
.footer li { margin-bottom: 9px; }
.footer li a:hover { color: #fff; }
.footer__contact svg { width: 15px; height: 15px; flex: none; margin-top: 5px; color: #6f7884; }
.footer__contact li { display: flex; gap: 9px; align-items: flex-start; }

.footer__bottom {
  border-top: 1px solid #2b3036; padding: 18px 0 26px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px;
}
.footer__bottom a:hover { color: #fff; }
.beian { display: inline-flex; align-items: center; gap: 5px; }
.beian svg { width: 13px; height: 13px; opacity: .7; }

/* ---------- 内页页头 ---------- */
.page-head {
  padding: calc(var(--header-h) + 48px) 0 40px; border-bottom: 1px solid var(--line); background: var(--bg-soft);
}
.page-head h1 { font-size: 30px; margin-bottom: 10px; }
.page-head p { color: var(--muted); font-size: 15.5px; max-width: 620px; }

/* ---------- 下载页 ---------- */
.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.dl {
  position: relative; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 20px; background: #fff; display: flex; flex-direction: column; transition: border-color .18s;
}
.dl:hover { border-color: #c3cddf; }
.dl__top { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.dl__ico { width: 38px; height: 38px; border-radius: 6px; display: grid; place-items: center; background: var(--brand-soft); color: var(--brand); flex: none; }
.dl__ico svg { width: 22px; height: 22px; }
.dl__top b { display: block; font-size: 16px; }
.dl__top span { font-size: 12.5px; color: var(--muted); }
.dl__meta { margin-bottom: 18px; }
.dl__meta div { display: flex; justify-content: space-between; font-size: 13.5px; padding: 6px 0; border-bottom: 1px solid var(--line-soft); }
.dl__meta div:last-child { border-bottom: 0; }
.dl__meta em { font-style: normal; color: var(--muted); }
.dl .btn { width: 100%; }
.dl__tip { margin-top: 10px; font-size: 12.5px; color: var(--muted); }
.dl__tag {
  position: absolute; top: 14px; right: 14px; font-size: 11.5px; font-weight: 500;
  padding: 2px 8px; border-radius: 4px; background: var(--brand-soft); color: var(--brand);
}

/* ---------- 功能详解 ---------- */
.feat-row { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.feat-row + .feat-row { margin-top: 56px; padding-top: 56px; border-top: 1px solid var(--line); }
.feat-row__text h3 { font-size: 22px; margin: 10px 0 12px; }
.feat-row__text > p { color: var(--ink-2); font-size: 15px; }
.feat-row__list { margin-top: 22px; display: grid; gap: 16px; }
.feat-row__list li { display: grid; grid-template-columns: 104px 1fr; gap: 16px; align-items: baseline; }
.feat-row__list b { font-size: 14px; font-weight: 600; }
.feat-row__list span { font-size: 13.5px; color: var(--muted); }

.panel { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: #fff; }
.panel__bar { padding: 10px 14px; background: #f2f4f7; border-bottom: 1px solid var(--line); font-size: 12.5px; color: var(--muted); }
.panel__body { padding: 18px 16px; background: #fbfbfc; }

.mini-rows { display: grid; gap: 10px; }
.mini-row { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 6px; background: #fff; }
.mini-row__ava { width: 30px; height: 30px; border-radius: 5px; display: grid; place-items: center; font-size: 11.5px; font-weight: 600; color: #fff; flex: none; }
.mini-row > div { flex: 1; min-width: 0; }
.mini-row b { display: block; font-size: 13.5px; font-weight: 600; }
.mini-row span { font-size: 12.5px; color: var(--muted); }
.mini-row em { font-style: normal; font-size: 12px; color: var(--muted); flex: none; }

.code {
  margin: 0; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 12.5px; line-height: 1.8;
  color: #3b424b; background: #f7f8fa; border: 1px solid var(--line-soft); border-radius: 6px;
  padding: 16px; overflow: auto;
}

/* ---------- 关于页 ---------- */
.about-grid { display: grid; grid-template-columns: 1fr 340px; gap: 48px; align-items: start; }
.about-grid h3 { font-size: 22px; margin-bottom: 14px; }
.about-grid p { color: var(--ink-2); margin-bottom: 12px; }

.info-list { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.info-list div { display: flex; gap: 16px; padding: 12px 18px; border-bottom: 1px solid var(--line-soft); font-size: 14px; }
.info-list div:last-child { border-bottom: 0; }
.info-list b { min-width: 96px; font-weight: 400; color: var(--muted); }
.info-list span { color: var(--ink); }

/* ---------- 动画 ---------- */
.reveal { opacity: 0; transition: opacity .5s ease; }
.reveal.is-in { opacity: 1; }

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero__grid { grid-template-columns: 1fr; gap: 36px; }
  .shot { max-width: 460px; }
  .cards, .dl-grid, .solutions { grid-template-columns: repeat(2, 1fr); }
  .devices { grid-template-columns: 1fr; }
  .devices__tabs { grid-template-columns: repeat(2, 1fr); }
  .feat-row, .about-grid, .cta { grid-template-columns: 1fr; gap: 28px; }
  .footer__top { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 860px) {
  .nav { display: none; }
  .header__inner { gap: 16px; }
  .burger { display: flex; }
  .header__actions .btn--ghost { display: none; }
  .logo { margin-right: auto; }
}

@media (max-width: 640px) {
  .section { padding: 52px 0; }
  .hero { padding-top: calc(var(--header-h) + 36px); }
  .hero h1 { font-size: 27px; }
  .cards, .dl-grid, .solutions, .devices__tabs, .kv, .footer__top { grid-template-columns: 1fr; }
  .row, .feat-row__list li { grid-template-columns: 1fr; gap: 6px; }
  .cta { padding: 26px 22px; }
  .page-head h1 { font-size: 25px; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; }
}