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

body {
  font-family: "Rajdhani", sans-serif;
  background: #0a0a0a;
  color: #ffffff;
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
}

/* 星空背景动画 */
.stars,
.stars2,
.stars3 {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
}

.stars {
  background: transparent
    url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="20" cy="20" r="0.5" fill="%23ffffff" opacity="0.8"/><circle cx="80" cy="40" r="0.3" fill="%2300ffff" opacity="0.6"/><circle cx="40" cy="70" r="0.4" fill="%23ff00ff" opacity="0.7"/><circle cx="90" cy="80" r="0.2" fill="%23ffff00" opacity="0.5"/><circle cx="10" cy="90" r="0.3" fill="%23ffffff" opacity="0.9"/></svg>')
    repeat;
  animation: moveStars 50s linear infinite;
}

.stars2 {
  background: transparent
    url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="15" cy="30" r="0.3" fill="%2300ffff" opacity="0.5"/><circle cx="70" cy="20" r="0.4" fill="%23ff00ff" opacity="0.6"/><circle cx="30" cy="80" r="0.2" fill="%23ffffff" opacity="0.7"/><circle cx="85" cy="60" r="0.3" fill="%23ffff00" opacity="0.4"/></svg>')
    repeat;
  animation: moveStars 100s linear infinite;
}

.stars3 {
  background: transparent
    url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="10" r="0.2" fill="%2300ffff" opacity="0.8"/><circle cx="25" cy="50" r="0.3" fill="%23ff00ff" opacity="0.5"/><circle cx="75" cy="75" r="0.4" fill="%23ffffff" opacity="0.6"/></svg>')
    repeat;
  animation: moveStars 75s linear infinite;
}

@keyframes moveStars {
  from {
    transform: translateY(0px);
  }
  to {
    transform: translateY(-100px);
  }
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
  position: relative;
  z-index: 1;
}

/* 头部样式 */
.header {
  text-align: center;
  margin-bottom: 4rem;
  position: relative;
}

.title {
  font-family: "Orbitron", monospace;
  margin-bottom: 1rem;
}

.title-main {
  display: block;
  font-size: 3.5rem;
  font-weight: 900;
  background: linear-gradient(45deg, #00ffff, #ff00ff, #ffff00, #00ffff);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s ease-in-out infinite;
  text-shadow: 0 0 30px rgba(0, 255, 255, 0.5);
  letter-spacing: 0.1em;
}

.title-sub {
  display: block;
  font-size: 1.2rem;
  font-weight: 400;
  color: #888;
  letter-spacing: 0.3em;
  margin-top: 0.5rem;
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.header-line {
  width: 200px;
  height: 2px;
  background: linear-gradient(90deg, transparent, #00ffff, transparent);
  margin: 2rem auto;
  position: relative;
  overflow: hidden;
}

.header-line::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, #ffffff, transparent);
  animation: scanLine 2s ease-in-out infinite;
}

@keyframes scanLine {
  0% {
    left: -100%;
  }
  100% {
    left: 100%;
  }
}

/* 导航网格 */
.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 4rem;
}

/* 导航卡片 */
.nav-card {
  background: rgba(15, 15, 15, 0.8);
  border: 1px solid rgba(0, 255, 255, 0.3);
  border-radius: 15px;
  padding: 0;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.nav-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(0, 255, 255, 0.1),
    transparent
  );
  transition: all 0.6s ease;
}

.nav-card:hover::before {
  left: 100%;
}

.nav-card:hover {
  transform: translateY(-10px);
  border-color: #00ffff;
  box-shadow: 0 20px 40px rgba(0, 255, 255, 0.2),
    0 0 20px rgba(0, 255, 255, 0.3), inset 0 0 20px rgba(0, 255, 255, 0.1);
}

.card-inner {
  padding: 2rem;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  position: relative;
  z-index: 2;
}

.card-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  filter: drop-shadow(0 0 10px currentColor);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-10px);
  }
}

.nav-card h3 {
  font-family: "Orbitron", monospace;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: #ffffff;
}

.nav-card p {
  color: #888;
  margin-bottom: 1.5rem;
  font-size: 1rem;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.8rem 1.5rem;
  background: linear-gradient(
    45deg,
    rgba(0, 255, 255, 0.1),
    rgba(255, 0, 255, 0.1)
  );
  border: 1px solid rgba(0, 255, 255, 0.5);
  border-radius: 25px;
  color: #ffffff;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card-link::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    45deg,
    rgba(0, 255, 255, 0.2),
    rgba(255, 0, 255, 0.2)
  );
  transition: all 0.3s ease;
}

.card-link:hover::before {
  left: 0;
}

.card-link:hover {
  border-color: #ffffff;
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.5);
  transform: scale(1.05);
}

.card-link span {
  position: relative;
  z-index: 1;
}

.arrow {
  transition: transform 0.3s ease;
}

.card-link:hover .arrow {
  transform: translateX(5px);
}

/* 分类标签（隐藏但用于未来扩展） */
.nav-card[data-category]::after {
  content: attr(data-category);
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-size: 0.7rem;
  background: rgba(0, 255, 255, 0.2);
  color: #00ffff;
  padding: 0.2rem 0.5rem;
  border-radius: 10px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.nav-card:hover[data-category]::after {
  opacity: 1;
}

/* 页脚 */
.footer {
  text-align: center;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(0, 255, 255, 0.3);
}

.footer-line {
  width: 100px;
  height: 1px;
  background: linear-gradient(90deg, transparent, #00ffff, transparent);
  margin: 0 auto 1rem auto;
}

.footer p {
  color: #666;
  font-size: 0.9rem;
  font-family: "Orbitron", monospace;
}
.footer a {
  color: #888;
  text-decoration: none;
  transition: color 0.3s ease;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  .title-main {
    font-size: 2.5rem;
  }

  .nav-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .card-inner {
    padding: 1.5rem;
  }

  .card-icon {
    font-size: 2.5rem;
  }
}

@media (max-width: 480px) {
  .title-main {
    font-size: 2rem;
  }

  .title-sub {
    font-size: 1rem;
  }

  .nav-grid {
    gap: 1rem;
  }

  .card-inner {
    padding: 1rem;
  }
}

/* 加载动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.nav-card {
  animation: fadeInUp 0.6s ease forwards;
}

.nav-card:nth-child(1) {
  animation-delay: 0.1s;
}
.nav-card:nth-child(2) {
  animation-delay: 0.2s;
}
.nav-card:nth-child(3) {
  animation-delay: 0.3s;
}
.nav-card:nth-child(4) {
  animation-delay: 0.4s;
}
.nav-card:nth-child(5) {
  animation-delay: 0.5s;
}
.nav-card:nth-child(6) {
  animation-delay: 0.6s;
}
.nav-card:nth-child(7) {
  animation-delay: 0.7s;
}
.nav-card:nth-child(8) {
  animation-delay: 0.8s;
}
.nav-card:nth-child(9) {
  animation-delay: 0.9s;
}
.nav-card:nth-child(10) {
  animation-delay: 1s;
}
.nav-card:nth-child(11) {
  animation-delay: 1.1s;
}
.nav-card:nth-child(12) {
  animation-delay: 1.2s;
}
.nav-card:nth-child(13) {
  animation-delay: 1.3s;
}
.nav-card:nth-child(14) {
  animation-delay: 1.4s;
}
.nav-card:nth-child(15) {
  animation-delay: 1.5s;
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: rgba(15, 15, 15, 0.8);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #00ffff, #ff00ff);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #ff00ff, #00ffff);
}