:root {
  --bg: #eef3fb;
  --card: #ffffff;
  --primary: #2b6ff2;
  --primary-dark: #1f57c4;
  --secondary: #16b3a8;
  --text: #1c2738;
  --muted: #5c6979;
  --border: #dfe7f2;
  --shadow-soft: 0 12px 34px rgba(14, 43, 92, 0.09);
  --shadow-hover: 0 16px 40px rgba(14, 43, 92, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(circle at top right, #f7faff 0%, var(--bg) 45%, #e9f0fb 100%);
  line-height: 1.65;
}

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

.site-header {
  background: linear-gradient(120deg, #0b2a5c 0%, #1f4f9f 42%, #2d7ef7 100%);
  color: #fff;
  padding: 34px 0 24px;
  box-shadow: 0 14px 30px rgba(8, 28, 66, 0.24);
}

.brand {
  margin: 0;
  font-size: clamp(26px, 3vw, 36px);
  letter-spacing: 1px;
}

.brand-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo {
  width: 46px;
  height: 46px;
  border-radius: 0;
  object-fit: cover;
  background: transparent;
  border: none;
  box-shadow: none;
  filter: drop-shadow(0 6px 14px rgba(8, 28, 66, 0.28));
}

.slogan {
  margin: 10px 0 0;
  opacity: 0.95;
  font-size: 16px;
}

#page-switcher {
  margin-top: 18px;
}

.page-switcher {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.switch-btn {
  text-decoration: none;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.45);
  color: #fff;
  backdrop-filter: blur(5px);
  transition: all 0.22s ease;
}

.switch-btn:hover,
.switch-btn.active {
  background: #fff;
  color: #0c2d66;
  transform: translateY(-2px);
  box-shadow: 0 8px 16px rgba(13, 44, 98, 0.18);
}

main {
  padding: 28px 0 50px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 24px;
  margin-bottom: 22px;
  box-shadow: var(--shadow-soft);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.card h2 {
  margin-top: 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 20px;
}

.carousel {
  position: relative;
  overflow: hidden;
  border-radius: 16px;
  min-height: 320px;
  box-shadow: 0 10px 24px rgba(15, 46, 97, 0.25);
}

.carousel-track {
  display: flex;
  transition: transform 0.45s ease;
}

.slide {
  flex: 0 0 100%;
  min-width: 100%;
  margin: 0;
  position: relative;
}

.slide img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  display: block;
}

.slide-caption {
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 14px;
  background: linear-gradient(90deg, rgba(6, 14, 34, 0.66), rgba(6, 14, 34, 0.42));
  color: #fff;
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 14px;
  backdrop-filter: blur(3px);
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  border: none;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.9);
  cursor: pointer;
  color: #0c2d66;
  box-shadow: 0 6px 14px rgba(15, 40, 87, 0.22);
  transition: all 0.2s ease;
}

.carousel-btn:hover {
  background: #fff;
  transform: translateY(-50%) scale(1.06);
}

.carousel-btn.prev {
  left: 12px;
}

.carousel-btn.next {
  right: 12px;
}

.dots {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: 10px;
  display: flex;
  gap: 8px;
}

.dot {
  width: 11px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: rgba(255, 255, 255, 0.7);
  cursor: pointer;
  transition: all 0.2s ease;
}

.dot.active {
  width: 22px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--secondary), var(--primary));
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.feature-item {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  background: #fff;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.feature-item:hover {
  transform: translateY(-3px);
  border-color: #c9d8ee;
  box-shadow: 0 10px 22px rgba(26, 63, 124, 0.1);
}

.feature-item h3 {
  margin: 0 0 8px;
}

.muted {
  color: var(--muted);
}

.message-layout {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 18px;
}

form label {
  display: block;
  font-weight: 600;
  margin: 10px 0 6px;
}

input,
textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid #d8e2f0;
  font: inherit;
  background: #fbfdff;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(43, 111, 242, 0.16);
  outline: none;
}

textarea {
  resize: vertical;
  min-height: 120px;
}

.primary-btn {
  margin-top: 12px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  color: #fff;
  padding: 11px 16px;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, filter 0.2s ease;
}

.primary-btn:hover {
  filter: brightness(0.98);
  transform: translateY(-1px);
  box-shadow: 0 10px 18px rgba(20, 88, 154, 0.24);
}

.message-card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
  padding: 14px 16px;
  margin-bottom: 10px;
  animation: fadeInUp 0.3s ease both;
}

.message-card header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.message-card time {
  color: var(--muted);
  font-size: 13px;
}

.empty-tip {
  color: var(--muted);
}

.site-footer {
  text-align: center;
  color: var(--muted);
  padding: 24px 0 34px;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 900px) {
  .site-header {
    padding-top: 28px;
  }

  .card {
    padding: 20px;
  }

  .hero-grid,
  .message-layout {
    grid-template-columns: 1fr;
  }

  .feature-list {
    grid-template-columns: 1fr;
  }
}