:root {
  --primary: #0A2D4C;
  --secondary: #1E3A5F;
  --accent: #27AE60;
  --text: #E0E0E0;
  --light: #F5F7FA;
  --dark: #34495E;
}

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

body {
  font-family: 'Roboto', 'Helvetica', Arial, sans-serif;
  background: radial-gradient(circle at 10% 20%, var(--primary), var(--secondary));
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(10, 45, 76, 0.9);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
  padding: 15px 0;
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(90deg, #3498DB, #27AE60);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-link {
  color: var(--light);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  transition: all 0.3s ease;
}

.nav-link:hover {
  color: var(--accent);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s ease;
}

.nav-link:hover::after {
  width: 100%;
}

.hero {
  height: 80vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
  opacity: 0.1;
  z-index: -1;
}

.hero-content {
  max-width: 600px;
}

.hero-title {
  font-size: 3.5rem;
  margin-bottom: 20px;
  background: linear-gradient(90deg, #3498DB, #27AE60);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.2rem;
  margin-bottom: 30px;
  color: rgba(255, 255, 255, 0.8);
}

.btn {
  display: inline-block;
  padding: 12px 30px;
  background: linear-gradient(90deg, #3498DB, #27AE60);
  color: white;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(39, 174, 96, 0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: all 0.6s ease;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(39, 174, 96, 0.4);
}

.btn:hover::before {
  left: 100%;
}

.particles {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  z-index: -1;
}

.particle {
  position: absolute;
  width: 2px;
  height: 2px;
  background: rgba(255, 255, 255, 0.5);
  border-radius: 50%;
  animation: float 15s infinite linear;
}

@keyframes float {
  0% {
    transform: translateY(0) translateX(0);
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  90% {
    opacity: 1;
  }
  100% {
    transform: translateY(-100vh) translateX(100px);
    opacity: 0;
  }
}

.section {
  padding: 100px 0;
  position: relative;
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 50px;
  text-align: center;
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -15px;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #3498DB, #27AE60);
  border-radius: 3px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 30px;
}

.card {
  grid-column: span 4;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
  border-color: rgba(52, 152, 219, 0.3);
}

.card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 20px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
}

.card:hover .card-img {
  transform: scale(1.03);
}

.card-title {
  font-size: 1.5rem;
  margin-bottom: 15px;
  color: white;
}

.card-desc {
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 20px;
}

.article {
  background: rgba(30, 58, 95, 0.7);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 50px;
  margin: 100px 0;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.article h2 {
  font-size: 2.2rem;
  margin-bottom: 30px;
  color: white;
  position: relative;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, #3498DB, #27AE60);
  border-radius: 3px;
}

.article h3 {
  font-size: 1.8rem;
  margin: 40px 0 20px;
  color: #3498DB;
}

.article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
  line-height: 1.8;
}

pre {
  background: rgba(10, 45, 76, 0.5);
  border-radius: 10px;
  padding: 20px;
  margin: 30px 0;
  overflow: auto;
  border-left: 4px solid #3498DB;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.6;
  color: #E0E0E0;
}

code {
  font-family: 'Courier New', monospace;
  background: rgba(0, 0, 0, 0.2);
  padding: 2px 5px;
  border-radius: 3px;
  color: #27AE60;
}

.footer {
  background: rgba(10, 45, 76, 0.9);
  padding: 50px 0 20px;
  margin-top: 100px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  margin-bottom: 50px;
}

.footer-col h4 {
  font-size: 1.3rem;
  margin-bottom: 20px;
  color: white;
  position: relative;
  display: inline-block;
}

.footer-col h4::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 50%;
  height: 2px;
  background: linear-gradient(90deg, #3498DB, #27AE60);
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: all 0.3s ease;
  display: inline-block;
}

.footer-col a:hover {
  color: #27AE60;
  transform: translateX(5px);
}

.social-links {
  display: flex;
  gap: 15px;
  margin-top: 20px;
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.social-link:hover {
  background: #27AE60;
  transform: translateY(-5px);
}

.copyright {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.9rem;
}

.notice {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: rgba(10, 45, 76, 0.9);
  backdrop-filter: blur(10px);
  padding: 15px 25px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  z-index: 1000;
  border: 1px solid rgba(255, 255, 255, 0.1);
  animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@media (max-width: 1024px) {
  .grid {
    grid-template-columns: repeat(9, 1fr);
  }
  
  .card {
    grid-column: span 3;
  }
  
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid {
    grid-template-columns: repeat(6, 1fr);
  }
  
  .card {
    grid-column: span 3;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .section-title {
    font-size: 2rem;
  }
  
  .article {
    padding: 30px;
  }
}

@media (max-width: 576px) {
  .grid {
    grid-template-columns: repeat(1, 1fr);
  }
  
  .card {
    grid-column: span 1;
  }
  
  .nav-links {
    display: none;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

/* Animation classes */
.fade-in {
  animation: fadeIn 1s ease-in-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.slide-in-left {
  animation: slideInLeft 0.8s ease-out;
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.slide-in-right {
  animation: slideInRight 0.8s ease-out;
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Decorative elements */
.decor-circle {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.15;
  z-index: -1;
}

.circle-1 {
  width: 300px;
  height: 300px;
  background: #3498DB;
  top: 10%;
  left: 5%;
  animation: float 20s infinite alternate;
}

.circle-2 {
  width: 400px;
  height: 400px;
  background: #27AE60;
  bottom: 10%;
  right: 5%;
  animation: float 25s infinite alternate-reverse;
}

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