/* 门户首页 —— 背景插画 + 暗色遮罩 + 发光标题 + 玻璃导航卡片 */

:root {
  --portal-bg-0: #05060c;
  --portal-bg-1: #0b0e1a;
  --portal-text: #f3f5fa;
  --portal-text-dim: #9aa3b8;
  --portal-card: rgba(10, 14, 26, 0.42);
  --portal-card-hover: rgba(20, 26, 44, 0.55);
  --portal-border: rgba(255, 255, 255, 0.12);
  --portal-border-hover: rgba(255, 255, 255, 0.26);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei UI", "Microsoft YaHei",
    system-ui, -apple-system, sans-serif;
  color: var(--portal-text);
  background-color: var(--portal-bg-0);
  min-height: 100vh;
  overflow: hidden;
  position: relative;
}

/* 背景插画层 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: url("/backgroup/IMG1766483671387.jpg") center 30% / cover no-repeat;
  z-index: 0;
}

/* 暗色遮罩层:保证前景文字可读,底部渐深衔接备案栏 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(1200px 700px at 50% 42%, rgba(5, 6, 12, 0.30), rgba(5, 6, 12, 0.72) 78%),
    linear-gradient(180deg, rgba(5, 6, 12, 0.55) 0%, rgba(5, 6, 12, 0.35) 40%, rgba(5, 6, 12, 0.78) 100%);
  z-index: 0;
}

/* 漂浮光点粒子层 */
#particles {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}
.particle {
  position: absolute;
  border-radius: 50%;
  background: rgba(200, 210, 235, 0.55);
  box-shadow: 0 0 6px 1px rgba(180, 200, 255, 0.35);
  animation: drift linear infinite, twinkle ease-in-out infinite;
}
@keyframes twinkle {
  0%, 100% { opacity: 0.15; }
  50% { opacity: 0.85; }
}
@keyframes drift {
  from { transform: translateY(0); }
  to { transform: translateY(-28px); }
}

/* 主体布局 */
.portal-stage {
  position: relative;
  z-index: 2;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px 96px;
}

.portal-title {
  margin: 0 0 46px;
  font-size: clamp(30px, 5.6vw, 54px);
  font-weight: 800;
  letter-spacing: 0.06em;
  color: #ffffff;
  text-align: center;
  text-shadow:
    0 2px 10px rgba(0, 0, 0, 0.55),
    0 0 12px rgba(255, 255, 255, 0.55),
    0 0 34px rgba(150, 180, 255, 0.35),
    0 0 70px rgba(120, 150, 255, 0.18);
  animation: title-glow 4.5s ease-in-out infinite;
}
@keyframes title-glow {
  0%, 100% {
    text-shadow:
      0 2px 10px rgba(0, 0, 0, 0.55),
      0 0 12px rgba(255, 255, 255, 0.5),
      0 0 34px rgba(150, 180, 255, 0.3),
      0 0 70px rgba(120, 150, 255, 0.15);
  }
  50% {
    text-shadow:
      0 2px 10px rgba(0, 0, 0, 0.55),
      0 0 18px rgba(255, 255, 255, 0.7),
      0 0 44px rgba(150, 180, 255, 0.45),
      0 0 90px rgba(120, 150, 255, 0.25);
  }
}

.portal-nav {
  display: flex;
  flex-direction: column;
  gap: 18px;
  width: min(94vw, 680px);
}

.portal-card {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 20px 26px;
  border-radius: 16px;
  border: 1px solid var(--portal-border);
  background: var(--portal-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  transition: transform .2s ease, border-color .2s ease, background .2s ease, box-shadow .2s ease;
}
.portal-card:hover {
  transform: translateY(-3px);
  border-color: var(--portal-border-hover);
  background: var(--portal-card-hover);
  box-shadow: 0 14px 40px rgba(0, 0, 0, 0.45);
}
.portal-card:active { transform: translateY(-1px); }

.portal-icon {
  flex: none;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.10);
  color: #e7eaf4;
}
.portal-icon svg { width: 24px; height: 24px; }

.portal-card-title {
  font-size: 17px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 3px;
}
.portal-card-desc {
  font-size: 13px;
  color: var(--portal-text-dim);
}

/* 悬停时滑入的箭头 */
.portal-arrow {
  margin-left: auto;
  flex: none;
  color: #cdd8f2;
  opacity: 0;
  transform: translateX(-8px);
  transition: opacity .2s ease, transform .2s ease;
}
.portal-arrow svg { width: 20px; height: 20px; display: block; }
.portal-card:hover .portal-arrow {
  opacity: 1;
  transform: translateX(0);
}

/* 底部备案信息 */
.portal-footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 22px;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  padding: 0 16px;
  font-size: 12.5px;
  color: rgba(255, 255, 255, 0.42);
}
.portal-footer a {
  color: inherit;
  text-decoration: none;
}
.portal-footer a:hover { color: rgba(255, 255, 255, 0.65); }
.portal-footer .rec-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.portal-footer svg { width: 13px; height: 13px; opacity: 0.75; }

@media (max-width: 520px) {
  .portal-card { padding: 16px 18px; gap: 14px; }
  .portal-icon { width: 40px; height: 40px; }
  .portal-icon svg { width: 20px; height: 20px; }
}