:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: rgba(20, 20, 30, 0.7);
  --text-primary: #ffffff;
  --text-secondary: #8a8a9a;
  --accent-cyan: #00f5ff;
}

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

body {
  font-family: system-ui, -apple-system, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  background-image: 
    radial-gradient(circle at 15% 50%, rgba(0, 245, 255, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 85% 30%, rgba(255, 0, 255, 0.08) 0%, transparent 50%);
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

header {
  text-align: center;
  margin-bottom: 4rem;
}

h1 {
  font-size: 3.5rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 2rem;
}

.tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 2rem;
}

.tab-button {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  padding: 0.8rem 1.5rem;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.tab-button:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
}

.tab-button.active {
  background: var(--accent-cyan);
  color: #000;
  box-shadow: 0 0 15px rgba(0, 245, 255, 0.4);
  border-color: var(--accent-cyan);
}

.card {
  display: none;
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 24px;
  padding: 3rem;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  margin-bottom: 3rem;
  animation: fadeIn 0.4s ease-out forwards;
}

.card.active-tab {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.card-header h2 {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.content h3 {
  margin: 2rem 0 1rem;
  color: var(--text-primary);
}

.content p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 1rem;
}

.content ul {
  list-style: none;
  margin-bottom: 1.5rem;
}

.content li {
  color: var(--text-secondary);
  line-height: 1.7;
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.5rem;
}

.content li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent-cyan);
}

.step-box {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 12px;
  padding: 1.5rem;
  margin-top: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.03);
}

.step {
  display: flex;
  align-items: center;
  margin-bottom: 1rem;
}

.step:last-child {
  margin-bottom: 0;
}

.step-number {
  background: rgba(255, 255, 255, 0.1);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  margin-right: 1rem;
}

footer {
  text-align: center;
  margin-top: 5rem;
  color: var(--text-secondary);
}