/* 张拉计算GUI 官网 — 专业深蓝主题 */
:root {
  --navy-900: #0a1f38;
  --navy-800: #0f2a4a;
  --navy-700: #123a63;
  --blue-500: #2e86de;
  --blue-600: #1f6fbe;
  --ink: #16243a;
  --ink-soft: #5a6b82;
  --bg: #f5f7fa;
  --bg-soft: #eef4fb;
  --card: #ffffff;
  --line: #e3e9f2;
  --gold: #f0b429;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

a { color: var(--blue-500); }

.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* ===== 顶部导航 ===== */
.topbar {
  background: var(--navy-800);
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 1px 0 rgba(0,0,0,.15);
}
.topbar-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  height: 60px;
}
.brand { color: #fff; font-size: 18px; font-weight: 700; text-decoration: none; white-space: nowrap; }
.brand span { color: #7fb3f0; }
.nav { display: flex; gap: 18px; margin-left: auto; align-items: center; }
.nav a { color: #cfe0f2; text-decoration: none; font-size: 14px; }
.nav a:hover { color: #fff; }
.nav-buy {
  background: var(--blue-500);
  color: #fff !important;
  padding: 7px 16px;
  border-radius: 6px;
}
.nav-buy:hover { background: var(--blue-600); }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, var(--navy-800), var(--navy-700));
  color: #fff;
  padding: 72px 0 84px;
  text-align: center;
}
.hero h1 { font-size: 34px; font-weight: 800; letter-spacing: .5px; }
.hero p { color: #c9dcf0; font-size: 16px; margin: 14px auto 26px; max-width: 560px; }
.hero .btn-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 11px 24px;
  border-radius: 7px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-primary { background: var(--blue-500); color: #fff; }
.btn-primary:hover { background: var(--blue-600); }
.btn-ghost { background: transparent; color: #cfe0f2; border-color: #3d5a7f; }
.btn-ghost:hover { color: #fff; border-color: #7fb3f0; }
.btn-block { display: block; width: 100%; text-align: center; }

/* ===== 通用区块 ===== */
.section { padding: 56px 0; }
.section-head { text-align: center; margin-bottom: 36px; }
.section-head h2 { font-size: 26px; font-weight: 700; }
.section-head p { color: var(--ink-soft); margin-top: 8px; }

/* ===== 功能卡片 ===== */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 24px 20px;
}
.feature .icon {
  width: 42px; height: 42px; border-radius: 9px;
  background: var(--bg-soft); color: var(--blue-600);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; margin-bottom: 14px;
}
.feature h3 { font-size: 16px; margin-bottom: 6px; }
.feature p { font-size: 14px; color: var(--ink-soft); }

/* ===== 套餐卡片 ===== */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.plan {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 28px 22px;
  text-align: center;
  position: relative;
  display: flex;
  flex-direction: column;
}
.plan.featured { border-color: var(--blue-500); box-shadow: 0 6px 22px rgba(46,134,222,.14); }
.plan .tag {
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--gold); color: #5a3a00;
  font-size: 12px; font-weight: 700;
  padding: 3px 12px; border-radius: 12px; white-space: nowrap;
}
.plan .plan-name { font-size: 16px; font-weight: 700; color: var(--navy-800); }
.plan .plan-days { font-size: 13px; color: var(--ink-soft); margin-top: 2px; }
.plan .price { font-size: 40px; font-weight: 800; margin: 16px 0 4px; color: var(--ink); }
.plan .price small { font-size: 16px; font-weight: 600; color: var(--ink-soft); }
.plan ul { list-style: none; margin: 16px 0 22px; text-align: left; }
.plan li { font-size: 14px; color: var(--ink-soft); padding: 5px 0; }
.plan li::before { content: "✓"; color: var(--blue-500); margin-right: 8px; font-weight: 700; }

/* ===== 页脚 ===== */
.footer { background: var(--navy-900); color: #9db4cd; padding: 36px 0; text-align: center; margin-top: 24px; }
.footer .footer-domain { color: #cfe0f2; font-size: 14px; font-weight: 600; margin: 6px 0; }
.footer-meta { font-size: 12px; }

/* ===== 支付页 ===== */
.buy-box {
  max-width: 640px;
  margin: 0 auto;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 32px 28px;
}
.buy-plan-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 22px; }
.buy-plan {
  border: 2px solid var(--line);
  border-radius: 10px;
  padding: 16px 8px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s;
}
.buy-plan.active { border-color: var(--blue-500); background: var(--bg-soft); }
.buy-plan input { display: none; }
.buy-plan .name { font-weight: 700; color: var(--navy-800); }
.buy-plan .price { font-size: 22px; font-weight: 800; margin-top: 4px; }
.buy-plan .days { font-size: 12px; color: var(--ink-soft); }
.buy-summary { background: var(--bg-soft); border-radius: 8px; padding: 14px 16px; margin-bottom: 18px; font-size: 14px; }
.buy-summary .total { font-size: 18px; font-weight: 700; color: var(--ink); }
.pay-method { display: flex; align-items: center; gap: 10px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 8px; margin-bottom: 20px; }
.pay-method .logo { width: 26px; height: 26px; border-radius: 6px; background: #1677ff; color: #fff; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; }
.error-box { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; border-radius: 8px; padding: 12px 14px; font-size: 14px; margin-bottom: 18px; }

/* ===== 结果页 ===== */
.result-box {
  max-width: 560px; margin: 0 auto; text-align: center;
  background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 40px 28px;
}
.code-display {
  font-family: ui-monospace, Consolas, monospace;
  font-size: 22px; font-weight: 700; letter-spacing: 1px;
  color: var(--blue-600);
  background: var(--bg-soft);
  border: 1px dashed var(--blue-500);
  border-radius: 8px;
  padding: 16px;
  margin: 18px 0;
  word-break: break-all;
}
.spinner {
  display: inline-block; width: 26px; height: 26px;
  border: 3px solid var(--line); border-top-color: var(--blue-500);
  border-radius: 50%; animation: spin 1s linear infinite; margin-bottom: 12px;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ===== 响应式 ===== */
@media (max-width: 760px) {
  .hero h1 { font-size: 26px; }
  .features { grid-template-columns: 1fr; }
  .plans { grid-template-columns: 1fr; }
  .buy-plan-row { grid-template-columns: 1fr; }
  .nav { gap: 12px; }
}