/*
 * Legacy browser fallback.
 * This file intentionally avoids Tailwind v4, CSS variables, dvh, backdrop-filter,
 * arbitrary selectors, and other modern syntax that older Tencent/IE-compatible
 * browser engines may ignore.
 */

html,
body {
  margin: 0;
  min-height: 100%;
  font-family: Arial, "Microsoft YaHei", "PingFang SC", sans-serif;
  color: #0f172a;
  background: #fff;
}

img,
video {
  max-width: 100%;
}

a {
  color: inherit;
}

header {
  display: block;
  position: sticky;
  top: 0;
  z-index: 40;
  min-height: 64px;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid #e2e8f0;
}

header > div {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 16px;
}

header > div > div {
  display: flex;
  align-items: center;
  gap: 22px;
  min-height: 64px;
}

header a[aria-label*="官网首页"] {
  display: flex;
  align-items: center;
  flex: 0 0 180px;
  width: 180px;
  max-width: 180px;
  overflow: hidden;
  text-decoration: none;
}

header a[aria-label*="官网首页"] img {
  display: block;
  width: 180px !important;
  max-width: 180px !important;
  height: auto !important;
}

header nav {
  display: flex;
  flex: 1 1 auto;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-width: 0;
}

header nav > div {
  position: relative;
}

header nav > div > a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 8px 10px;
  border-radius: 8px;
  color: #475569;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
}

header nav > div > a:hover {
  color: #0f172a;
  background: #f8fafc;
}

header nav > div > div {
  display: none;
}

header nav > div:hover > div,
header nav > div:focus-within > div {
  display: block;
  position: absolute;
  top: 100%;
  left: 50%;
  z-index: 50;
  width: 288px;
  padding-top: 10px;
  transform: translateX(-50%);
}

header nav > div > div > div {
  padding: 8px;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  background: #fff;
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.12);
}

header nav > div > div a {
  display: block;
  padding: 10px 12px;
  border-radius: 8px;
  color: #334155;
  text-decoration: none;
}

header nav > div > div a:hover {
  background: #f8fafc;
}

header nav span {
  display: block;
}

header button[aria-controls="mobile-site-nav"] {
  display: none;
}

body > div,
header + div {
  min-width: 0;
}

.min-h-screen {
  min-height: 100vh;
}

.max-w-7xl,
.mx-auto.max-w-7xl {
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
}

.px-4 {
  padding-left: 16px;
  padding-right: 16px;
}

.py-8 {
  padding-top: 32px;
  padding-bottom: 32px;
}

.bg-white {
  background: #fff;
}

.text-white {
  color: #fff;
}

.rounded-lg,
.rounded-xl,
.rounded-2xl {
  border-radius: 12px;
}

.border {
  border: 1px solid #e2e8f0;
}

.shadow-sm {
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.08);
}

.aspect-video {
  position: relative;
  width: 100%;
}

.aspect-video:before {
  display: block;
  padding-top: 56.25%;
  content: "";
}

.aspect-video > img,
.aspect-video > video,
.aspect-video > div {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.object-cover {
  object-fit: cover;
}

.grid {
  display: grid;
}

.flex {
  display: flex;
}

.hidden {
  display: none;
}

header .hidden,
header nav.hidden {
  display: flex;
}

.overflow-hidden {
  overflow: hidden;
}

.space-y-3 > * + * {
  margin-top: 12px;
}

.gap-2 {
  gap: 8px;
}

.gap-3 {
  gap: 12px;
}

.gap-6 {
  gap: 24px;
}

button,
.legacy-button,
a[class*="rounded"] {
  cursor: pointer;
}

@media (min-width: 1024px) {
  .lg\:grid-cols-\[1\.15fr_0\.85fr\],
  .lg\:grid-cols-\[1\.16fr_0\.84fr\] {
    grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  }
}

@media (max-width: 767px) {
  header > div > div {
    gap: 12px;
  }

  header a[aria-label*="官网首页"] {
    flex-basis: 150px;
    width: 150px;
    max-width: 150px;
  }

  header a[aria-label*="官网首页"] img {
    width: 150px !important;
    max-width: 150px !important;
  }

  header nav {
    display: none;
  }

  header .hidden,
  header nav.hidden {
    display: none;
  }

  header button[aria-controls="mobile-site-nav"] {
    display: block;
    margin-left: auto;
  }
}