:root {
  --primary: #121212;
  --secondary: #1E90FF;
  --accent: #FF4500;
  --text: #FFFFFF;
  --gray: #2C2C2C;
  --light-gray: #1E1E1E;
}

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

body {
  background-color: var(--primary);
  color: var(--text);
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  padding: 0;
  margin: 0;
  min-height: 100%;
  background-image: radial-gradient(circle at 20% 30%, rgba(30, 144, 255, 0.1) 0%, transparent 40%), 
                    radial-gradient(circle at 80% 70%, rgba(255, 69, 0, 0.1) 0%, transparent 40%);
}

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

.header {
  text-align: center;
  padding: 40px 0;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(30, 144, 255, 0.2) 0%, rgba(255, 69, 0, 0.2) 100%);
  z-index: -1;
  opacity: 0.5;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 0 10px rgba(30, 144, 255, 0.3);
}

.notice {
  background-color: rgba(30, 144, 255, 0.1);
  border-left: 4px solid var(--secondary);
  padding: 15px;
  margin: 20px 0;
  border-radius: 0 5px 5px 0;
  font-size: 0.9rem;
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.section {
  background-color: var(--light-gray);
  border-radius: 10px;
  padding: 30px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
}

.section:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
}

.section::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
}

.section h2 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  color: var(--secondary);
  position: relative;
  padding-bottom: 10px;
}

.section h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 50px;
  height: 2px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
}

.section h3 {
  font-size: 1.4rem;
  margin: 25px 0 15px;
  color: var(--text);
}

.section p {
  margin-bottom: 15px;
  font-size: 1.1rem;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-card {
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.5s ease;
}

.image-card:hover img {
  transform: scale(1.05);
}

.code-block {
  background-color: #1E1E1E;
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  position: relative;
  border-left: 4px solid var(--secondary);
}

.code-block::before {
  content: "CSS";
  position: absolute;
  top: 0;
  right: 0;
  background-color: var(--secondary);
  color: white;
  padding: 2px 10px;
  font-size: 0.8rem;
  border-radius: 0 0 0 5px;
}

.code-block pre {
  margin: 0;
  white-space: pre-wrap;
}

.code-block code {
  color: #A9B7C6;
  font-size: 0.95rem;
  line-height: 1.5;
}

.color-swatch {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  margin-right: 5px;
  vertical-align: middle;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
}

.nav-tabs {
  display: flex;
  margin-bottom: 30px;
  border-bottom: 1px solid var(--gray);
}

.nav-tab {
  padding: 10px 20px;
  cursor: pointer;
  position: relative;
  color: var(--text);
  opacity: 0.7;
  transition: all 0.3s ease;
}

.nav-tab:hover {
  opacity: 1;
}

.nav-tab.active {
  opacity: 1;
  color: var(--secondary);
}

.nav-tab.active::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
}

.footer {
  text-align: center;
  padding: 30px 0;
  margin-top: 50px;
  border-top: 1px solid var(--gray);
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.6);
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .section {
    padding: 20px;
  }
  
  .section h2 {
    font-size: 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

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

.floating {
  animation: float 3s ease-in-out infinite;
}