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

body {
  font-family:
    system-ui,
    -apple-system,
    "Segoe UI",
    Roboto,
    Helvetica,
    Arial,
    sans-serif;
  background-color: #ffffff;
  color: #0a1a3a;
  line-height: 1.5;
}

/* 动态背景插图 – 抽象柔和的缓动动画 */
.bg-illustration {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background:
    radial-gradient(
      circle at 10% 20%,
      rgba(30, 80, 255, 0.07) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 90% 80%,
      rgba(0, 40, 200, 0.08) 0%,
      transparent 60%
    ),
    linear-gradient(135deg, #f0f6ff 0%, #ffffff 70%);
  animation: floatBg 18s ease-in-out infinite alternate;
}

@keyframes floatBg {
  0% {
    background:
      radial-gradient(
        circle at 20% 30%,
        rgba(40, 90, 255, 0.1) 0%,
        transparent 45%
      ),
      radial-gradient(
        circle at 80% 70%,
        rgba(0, 50, 200, 0.1) 0%,
        transparent 55%
      ),
      linear-gradient(145deg, #eef4ff 0%, #ffffff 80%);
  }
  50% {
    background:
      radial-gradient(
        circle at 70% 20%,
        rgba(20, 70, 240, 0.12) 0%,
        transparent 50%
      ),
      radial-gradient(
        circle at 20% 80%,
        rgba(0, 30, 180, 0.1) 0%,
        transparent 50%
      ),
      linear-gradient(215deg, #e5eeff 0%, #fafcff 90%);
  }
  100% {
    background:
      radial-gradient(
        circle at 40% 60%,
        rgba(50, 100, 255, 0.08) 0%,
        transparent 50%
      ),
      radial-gradient(
        circle at 70% 30%,
        rgba(10, 40, 200, 0.12) 0%,
        transparent 45%
      ),
      linear-gradient(180deg, #f2f8ff 0%, #ffffff 85%);
  }
}

/* 主容器 */
.app {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem 2rem;
  position: relative;
}

/* 导航 */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 0 2rem;
  flex-wrap: wrap;
  border-bottom: 1px solid rgba(0, 40, 200, 0.08);
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: #0a2a7a;
}
.logo span {
  color: #1a5cff;
}

.nav-links {
  display: flex;
  gap: 2.2rem;
  flex-wrap: wrap;
  font-weight: 500;
}

.nav-links a {
  text-decoration: none;
  color: #0a2a6a;
  font-size: 1.05rem;
  transition:
    color 0.2s,
    border-bottom 0.2s;
  padding-bottom: 0.2rem;
  border-bottom: 2px solid transparent;
}

.nav-links a:hover {
  color: #0044ff;
  border-bottom-color: #0044ff;
}

/* 栅格布局 通用 */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem 2.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem;
}

/* 区块间距 */
section {
  padding: 3.5rem 0 2.5rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 2rem;
  color: #0a2a6a;
  letter-spacing: -0.02em;
  border-left: 6px solid #1a5cff;
  padding-left: 1rem;
}

/* banner */
.banner {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  padding: 1.5rem 0 2.5rem;
  flex-wrap: wrap;
}

.banner-text {
  flex: 1 1 45%;
}

.banner-text h1 {
  font-size: 3.2rem;
  font-weight: 700;
  line-height: 1.1;
  color: #0a1f4a;
  letter-spacing: -0.02em;
}

.banner-text h1 span {
  color: #1a5cff;
}

.banner-text .tagline {
  font-size: 1.2rem;
  margin: 1rem 0 1.5rem;
  color: #1d3a7a;
  opacity: 0.8;
  max-width: 90%;
}

.banner-image {
  flex: 1 1 35%;
  display: flex;
  justify-content: center;
  transition:
    transform 0.25s ease,
    box-shadow 0.3s;
  cursor: default;
}

.banner-image img {
  width: 100%;
  max-width: 260px;
  height: auto;
  border-radius: 32px;
  box-shadow: 0 20px 40px -12px rgba(0, 30, 120, 0.25);
  transition:
    transform 0.3s ease,
    box-shadow 0.3s;
  border: 1px solid rgba(255, 255, 255, 0.3);
  display: block;
}

/* 鼠标交互 : 悬浮放大 + 柔和阴影 */
.banner-image:hover img {
  transform: scale(1.03) rotate(0.5deg);
  box-shadow: 0 30px 50px -16px rgba(0, 50, 200, 0.35);
}

/* 分段描述 – 栅格布局 */
.desc-card {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(2px);
  padding: 1.8rem 1.8rem 2rem;
  border-radius: 28px;
  box-shadow: 0 6px 18px rgba(0, 30, 100, 0.04);
  transition: all 0.2s;
  border: 1px solid rgba(0, 60, 255, 0.06);
}

.desc-card h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: #0a2a6a;
}

.desc-card p {
  color: #1f3a6a;
  font-size: 1rem;
  line-height: 1.6;
}

.desc-card strong {
  color: #0044ee;
  font-weight: 600;
}

/* screenshots 卡片 */
.shot-card {
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(2px);
  border-radius: 32px;
  padding: 1.5rem 1.5rem 2rem;
  border: 1px solid rgba(0, 40, 200, 0.06);
  transition: transform 0.2s;
  box-shadow: 0 6px 14px rgba(0, 20, 80, 0.02);
  text-align: center;
}

.shot-card:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.7);
}

.shot-card .mock-img {
  width: 100%;
  aspect-ratio: 9 / 16;
  max-width: 140px;
  margin: 0 auto 1rem;
  background: linear-gradient(145deg, #d4e0ff, #b8caff);
  border-radius: 24px;
  box-shadow: 0 8px 18px rgba(0, 30, 120, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0a2a6a;
  font-weight: 500;
  font-size: 1rem;
  border: 1px solid white;
}

.shot-card .mock-img span {
  background: rgba(255, 255, 255, 0.3);
  padding: 0.3rem 0.8rem;
  border-radius: 40px;
  backdrop-filter: blur(2px);
}

.shot-card h4 {
  font-size: 1.2rem;
  color: #0a2a6a;
  margin-bottom: 0.3rem;
}

.shot-card p {
  color: #2f4a7a;
  font-size: 0.95rem;
}

/* footer / contact */
.footer {
  border-top: 1px solid rgba(0, 40, 200, 0.08);
  margin-top: 2rem;
  padding: 2.5rem 0 1.5rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-email {
  font-size: 1.1rem;
  background: rgba(0, 60, 255, 0.02);
  padding: 0.2rem 1rem 0.2rem 0;
  color: #0a2a7a;
}

.footer-email a {
  color: #0044ee;
  text-decoration: none;
  font-weight: 500;
  border-bottom: 1px dashed #0044ee50;
}

.footer-email a:hover {
  border-bottom-color: #0044ee;
}

.footer-copy {
  color: #3a4f7a;
  font-size: 0.95rem;
}

/* 移动端适配 */
@media screen and (max-width: 860px) {
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .grid-3 {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }
  .banner {
    flex-direction: column-reverse;
    text-align: center;
  }
  .banner-text {
    text-align: center;
  }
  .banner-text .tagline {
    max-width: 100%;
    margin-left: auto;
    margin-right: auto;
  }
  .banner-image img {
    max-width: 200px;
  }
  .nav-links {
    gap: 1.2rem;
    justify-content: center;
    width: 100%;
    margin-top: 0.5rem;
  }
  .logo {
    font-size: 1.6rem;
  }
}

@media screen and (max-width: 520px) {
  .grid-3 {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .app {
    padding: 0 1rem 1.5rem;
  }
  .section-title {
    font-size: 1.7rem;
  }
  .banner-text h1 {
    font-size: 2.5rem;
  }
}

/* 辅助 */
.mt-1 {
  margin-top: 0.8rem;
}