:root {
  --primary: #1B254F;
  --secondary: #F7F9FC;
  --accent: #651FFF;
  --text: #333;
  --light: #fff;
  --dark: #111;
}

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

body {
  font-family: 'Helvetica Neue', sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--secondary);
  overflow-x: hidden;
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: var(--primary);
  color: var(--light);
  padding: 15px 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

.logo {
  font-size: 24px;
  font-weight: 700;
  background: linear-gradient(90deg, var(--accent), #8A2BE2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

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

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

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

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

.nav a:hover::after {
  width: 100%;
}

.hero {
  height: 500px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: var(--light);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin-top: 60px;
  clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
  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: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 20px;
}

.hero h1 {
  font-size: 48px;
  margin-bottom: 20px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.hero p {
  font-size: 20px;
  margin-bottom: 30px;
  opacity: 0.9;
}

.notice {
  background: rgba(255,255,255,0.2);
  padding: 15px;
  border-radius: 8px;
  margin-top: 30px;
  backdrop-filter: blur(5px);
  border: 1px solid rgba(255,255,255,0.1);
}

.content {
  padding: 80px 0;
}

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

.main {
  grid-column: span 8;
}

.sidebar {
  grid-column: span 4;
}

article {
  background: var(--light);
  padding: 40px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  margin-bottom: 40px;
}

article h2 {
  font-size: 32px;
  color: var(--accent);
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

article h3 {
  font-size: 24px;
  color: var(--primary);
  margin: 30px 0 15px;
}

article p {
  margin-bottom: 20px;
  color: var(--text);
}

pre {
  background: #f5f5f5;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 20px 0;
  border-left: 4px solid var(--accent);
  font-size: 15px;
  line-height: 1.5;
}

code {
  font-family: 'Courier New', monospace;
  color: #333;
}

.card {
  background: var(--light);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: all 0.3s ease;
  margin-bottom: 30px;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.card img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 15px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

.card img:hover {
  transform: scale(1.02);
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.sidebar-widget {
  background: var(--light);
  padding: 25px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  margin-bottom: 30px;
}

.sidebar-widget h3 {
  font-size: 20px;
  color: var(--primary);
  margin-bottom: 15px;
  padding-bottom: 10px;
  border-bottom: 1px solid #eee;
}

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

.tag {
  background: #f0f0f0;
  padding: 5px 10px;
  border-radius: 20px;
  font-size: 14px;
  color: var(--text);
  transition: all 0.3s ease;
}

.tag:hover {
  background: var(--accent);
  color: var(--light);
}

.footer {
  background: var(--primary);
  color: var(--light);
  padding: 50px 0;
  text-align: center;
}

.footer p {
  opacity: 0.8;
  margin-bottom: 20px;
}

.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--accent);
  color: var(--light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 999;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.scroll-top.visible {
  opacity: 1;
}

.scroll-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

@media (max-width: 992px) {
  .grid {
    grid-template-columns: 1fr;
  }
  .main, .sidebar {
    grid-column: span 1;
  }
  .hero h1 {
    font-size: 36px;
  }
  .hero p {
    font-size: 18px;
  }
}

@media (max-width: 768px) {
  .nav {
    gap: 15px;
  }
  article {
    padding: 30px;
  }
  article h2 {
    font-size: 28px;
  }
  article h3 {
    font-size: 22px;
  }
}

@media (max-width: 576px) {
  .header-container {
    flex-direction: column;
    gap: 15px;
  }
  .nav {
    flex-wrap: wrap;
    justify-content: center;
  }
  .hero {
    height: 400px;
    clip-path: polygon(0 0, 100% 0, 100% 90%, 0 100%);
  }
  .hero h1 {
    font-size: 28px;
  }
  .hero p {
    font-size: 16px;
  }
  article {
    padding: 20px;
  }
  article h2 {
    font-size: 24px;
  }
  article h3 {
    font-size: 20px;
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.animate-on-scroll {
  opacity: 0;
}

.button {
  display: inline-block;
  background: var(--accent);
  color: var(--light);
  padding: 12px 25px;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.button:hover {
  background: #5328d0;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.button:active {
  transform: translateY(0);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}