/* ==========================================================
   多机投屏Pro 官方网站  —— 统一样式表
   纯静态、零依赖，可直接放到任意静态托管/服务器
   ========================================================== */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --brand:    #2563eb;
  --brand-d:  #1e40af;
  --brand-l:  #eff6ff;
  --ink:      #0f172a;
  --sub:      #475569;
  --muted:    #94a3b8;
  --line:     #e2e8f0;
  --bg:       #f6f8fc;
  --card:     #ffffff;
  --ok:       #16a34a;
  --warn:     #b45309;
  --warn-bg:  #fef3c7;
  --radius:   14px;
  --shadow:   0 1px 2px rgba(15,23,42,.04), 0 8px 24px rgba(15,23,42,.06);
}

html { scroll-behavior: smooth; }

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

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 760px; }

/* ---------- 顶部导航 ---------- */
header.site {
  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);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; color: var(--ink); }
.logo:hover { text-decoration: none; }
.logo .mark {
  width: 32px; height: 32px; border-radius: 9px; flex: 0 0 32px;
  background: linear-gradient(135deg, var(--brand), #0ea5e9);
  display: grid; place-items: center; color: #fff; font-size: 15px; font-weight: 800;
}
.nav ul { display: flex; gap: 26px; list-style: none; }
.nav ul a { color: var(--sub); font-size: 14.5px; font-weight: 500; }
.nav ul a:hover { color: var(--brand); text-decoration: none; }
.nav ul a.active { color: var(--brand); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 44px; padding: 0 22px; border-radius: 10px;
  font-size: 15px; font-weight: 600; cursor: pointer;
  border: 1px solid transparent; transition: .18s;
  text-decoration: none !important;
}
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 16px rgba(37,99,235,.28); }
.btn-primary:hover { background: var(--brand-d); transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-lg { height: 52px; padding: 0 30px; font-size: 16px; border-radius: 12px; }
.btn-block { width: 100%; }

/* ---------- Hero ---------- */
.hero {
  background: radial-gradient(1200px 480px at 15% -10%, #1e3a8a 0%, #0f172a 55%, #0b1220 100%);
  color: #fff; padding: 78px 0 84px; position: relative; overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(rgba(255,255,255,.07) 1px, transparent 1px);
  background-size: 26px 26px; opacity: .5; pointer-events: none;
}
.hero .wrap { position: relative; z-index: 1; }
.hero h1 { font-size: 40px; line-height: 1.28; letter-spacing: -.5px; font-weight: 800; }
.hero p.lead { font-size: 17px; color: #cbd5e1; margin-top: 18px; max-width: 640px; }
.hero .cta { display: flex; gap: 14px; margin-top: 32px; flex-wrap: wrap; }
.hero .btn-ghost { background: rgba(255,255,255,.08); color: #fff; border-color: rgba(255,255,255,.28); }
.hero .btn-ghost:hover { background: rgba(255,255,255,.16); color: #fff; border-color: rgba(255,255,255,.5); }
.hero .pills { display: flex; gap: 22px; flex-wrap: wrap; margin-top: 34px; color: #94a3b8; font-size: 14px; }
.hero .pills b { color: #fff; font-weight: 700; }

/* ---------- 通用区块 ---------- */
section { padding: 62px 0; }
section.tight { padding: 44px 0; }
.section-head { text-align: center; margin-bottom: 42px; }
.section-head h2 { font-size: 27px; font-weight: 800; letter-spacing: -.3px; }
.section-head p { color: var(--sub); margin-top: 10px; }

/* ---------- 卡片栅格 ---------- */
.grid { display: grid; gap: 20px; }
.grid.c2 { grid-template-columns: repeat(2, 1fr); }
.grid.c3 { grid-template-columns: repeat(3, 1fr); }
.grid.c4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow);
}
.card h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--sub); font-size: 14.5px; }
.card .ico {
  width: 42px; height: 42px; border-radius: 11px; background: var(--brand-l);
  color: var(--brand); display: grid; place-items: center; font-size: 20px; margin-bottom: 14px;
}

/* ---------- 价格 ---------- */
.price-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; align-items: stretch; }
.plan {
  background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 30px 26px;
  display: flex; flex-direction: column; box-shadow: var(--shadow); position: relative;
}
.plan.featured { border: 2px solid var(--brand); box-shadow: 0 12px 36px rgba(37,99,235,.16); }
.plan .tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--brand); color: #fff; font-size: 12px; font-weight: 700;
  padding: 4px 14px; border-radius: 20px; white-space: nowrap;
}
.plan h3 { font-size: 16px; font-weight: 700; color: var(--sub); }
.plan .amount { font-size: 40px; font-weight: 800; letter-spacing: -1px; margin: 14px 0 4px; }
.plan .amount small { font-size: 15px; font-weight: 600; color: var(--muted); letter-spacing: 0; }
.plan ul { list-style: none; margin: 20px 0 24px; flex: 1; }
.plan ul li { padding: 7px 0 7px 26px; position: relative; color: var(--sub); font-size: 14.5px; }
.plan ul li::before {
  content: "✓"; position: absolute; left: 0; top: 7px; color: var(--ok); font-weight: 800;
}

/* ---------- 表格 ---------- */
table.tbl { width: 100%; border-collapse: collapse; background: #fff; border-radius: 12px; overflow: hidden; box-shadow: var(--shadow); }
table.tbl th, table.tbl td { padding: 13px 16px; text-align: left; border-bottom: 1px solid var(--line); font-size: 14.5px; }
table.tbl th { background: #f8fafc; font-weight: 700; color: var(--sub); font-size: 13.5px; }
table.tbl tr:last-child td { border-bottom: none; }

/* ---------- 步骤 ---------- */
.steps { counter-reset: s; display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; position: relative; }
.step::before {
  counter-increment: s; content: counter(s);
  width: 34px; height: 34px; border-radius: 50%; background: var(--brand); color: #fff;
  display: grid; place-items: center; font-weight: 800; margin-bottom: 14px;
}
.step h3 { font-size: 16px; margin-bottom: 6px; }
.step p { color: var(--sub); font-size: 14.5px; }

/* ---------- 提示条 ---------- */
.notice {
  background: var(--brand-l); border: 1px solid #bfdbfe; color: #1e40af;
  border-radius: 12px; padding: 14px 18px; font-size: 14px;
}
.notice.ok  { background: #f0fdf4; border-color: #bbf7d0; color: #15803d; }
.notice.warn{ background: var(--warn-bg); border-color: #fde68a; color: var(--warn); }

/* ---------- 占位符（部署前必须替换）---------- */
.ph {
  background: var(--warn-bg); color: var(--warn); border-bottom: 1px dashed #f59e0b;
  padding: 0 3px; border-radius: 3px; font-weight: 600;
}

/* ---------- 表单 / 支付页 ---------- */
.pay-shell { display: grid; grid-template-columns: 1.15fr .85fr; gap: 24px; align-items: start; }
.panel { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); overflow: hidden; }
.panel .hd { padding: 16px 22px; border-bottom: 1px solid var(--line); font-weight: 700; background: #fbfcfe; }
.panel .bd { padding: 22px; }

.field { margin-bottom: 18px; }
.field label { display: block; font-size: 13.5px; font-weight: 600; color: var(--sub); margin-bottom: 7px; }
.field input[type=text], .field input[type=tel], .field input[type=email], .field select {
  width: 100%; height: 44px; padding: 0 13px; font-size: 15px;
  border: 1px solid var(--line); border-radius: 10px; background: #fff; color: var(--ink);
  font-family: inherit; outline: none; transition: .15s;
}
.field input:focus, .field select:focus { border-color: var(--brand); box-shadow: 0 0 0 3px rgba(37,99,235,.12); }
.field .hint { font-size: 12.5px; color: var(--muted); margin-top: 6px; }

.paymethods { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.pm {
  border: 2px solid var(--line); border-radius: 12px; padding: 14px; cursor: pointer;
  display: flex; align-items: center; gap: 11px; transition: .15s; background: #fff;
}
.pm:hover { border-color: #cbd5e1; }
.pm.on { border-color: var(--brand); background: var(--brand-l); }
.pm .dot { width: 18px; height: 18px; border-radius: 50%; border: 2px solid #cbd5e1; flex: 0 0 18px; position: relative; }
.pm.on .dot { border-color: var(--brand); }
.pm.on .dot::after { content: ""; position: absolute; inset: 3px; border-radius: 50%; background: var(--brand); }
.pm .nm { font-weight: 600; font-size: 14.5px; }
.pm .brandico { width: 26px; height: 26px; border-radius: 7px; display: grid; place-items: center; color: #fff; font-size: 13px; font-weight: 800; }
.pm .brandico.ali { background: #1677ff; }
.pm .brandico.wx  { background: #07c160; }

.summary-row { display: flex; justify-content: space-between; padding: 9px 0; font-size: 14.5px; color: var(--sub); }
.summary-row.total { border-top: 1px dashed var(--line); margin-top: 8px; padding-top: 14px; color: var(--ink); font-weight: 700; font-size: 16px; }
.summary-row.total .amt { color: #dc2626; font-size: 24px; font-weight: 800; letter-spacing: -.5px; }

.qrbox {
  border: 1px dashed #cbd5e1; border-radius: 14px; padding: 22px; text-align: center; background: #fbfcfe;
}
.qrbox .frame { width: 190px; height: 190px; margin: 0 auto 14px; background: #fff; border: 1px solid var(--line); border-radius: 12px; display: grid; place-items: center; }
.qrbox .tip { font-size: 13.5px; color: var(--sub); }

/* ---------- 页脚 ---------- */
footer.site {
  background: #0f172a; color: #94a3b8; padding: 46px 0 30px; font-size: 13.5px; margin-top: 20px;
}
footer.site .cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 30px; }
footer.site h4 { color: #fff; font-size: 14px; margin-bottom: 12px; font-weight: 700; }
footer.site a { color: #94a3b8; display: block; padding: 3px 0; }
footer.site a:hover { color: #fff; }
footer.site .bottom {
  border-top: 1px solid #1e293b; margin-top: 32px; padding-top: 20px;
  display: flex; justify-content: space-between; gap: 14px; flex-wrap: wrap; color: #64748b; font-size: 12.5px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .grid.c4, .grid.c3, .price-grid, .steps { grid-template-columns: 1fr 1fr; }
  .pay-shell { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .hero h1 { font-size: 28px; }
  .hero { padding: 54px 0 60px; }
  .grid.c4, .grid.c3, .grid.c2, .price-grid, .steps, .paymethods { grid-template-columns: 1fr; }
  .nav ul { gap: 14px; }
  .nav ul a { font-size: 13px; }
  footer.site .cols { grid-template-columns: 1fr; }
  section { padding: 44px 0; }
}