:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
  --accent: #39d353;
  --accent-dark: #176f3c;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.08);
}

[data-theme="dark"] {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-card: #161b22;
  --text-primary: #c9d1d9;
  --text-secondary: #8b949e;
  --border-color: #30363d;
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.3);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}

/* Header */
.app-header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}
.brand-section { display: flex; align-items: center; gap: 12px; }
.logo {
  display: flex; align-items: center; gap: 8px;
  font-size: 1.1rem; font-weight: 700; color: var(--text-primary);
}
.logo i { font-size: 1.3rem; color: var(--accent); }
.text-gradient { background: linear-gradient(135deg, var(--accent), #6ee77a); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.brand-badge {
  font-size: 0.65rem; font-weight: 600; padding: 2px 8px;
  border-radius: 4px; background: rgba(57,211,83,0.1); color: var(--accent);
}
.header-actions { display: flex; align-items: center; gap: 8px; }
.btn-icon {
  width: 36px; height: 36px; border-radius: 8px; border: 1px solid var(--border-color);
  background: var(--bg-card); color: var(--text-secondary);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: all 0.2s;
}
.btn-icon:hover { border-color: var(--accent); color: var(--accent); }
.btn-home {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 14px; border-radius: 8px; font-size: 0.8rem; font-weight: 600;
  background: var(--accent); color: #fff; text-decoration: none; transition: all 0.2s;
}
.btn-home:hover { background: var(--accent-dark); color: #fff; }

/* Main */
.main-content { min-height: calc(100vh - 120px); }

/* Info Card */
.info-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: 16px; padding: 32px; box-shadow: var(--shadow);
}
.tech-badge {
  display: inline-block; padding: 4px 12px; border-radius: 6px;
  font-size: 0.7rem; font-weight: 600;
  background: rgba(57,211,83,0.08); color: var(--accent);
}

/* Preview Card */
.preview-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: 16px; overflow: hidden; box-shadow: var(--shadow-lg);
}
.preview-header {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}
.preview-dots { display: flex; gap: 6px; }
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot-red { background: #ef4444; }
.dot-yellow { background: #f59e0b; }
.dot-green { background: #10b981; }
.preview-url { font-size: 0.75rem; color: var(--text-secondary); font-family: monospace; }
.preview-body { position: relative; height: 500px; overflow: hidden; background: #0d1117; }
.preview-body iframe {
  width: 100%; height: 100%; border: none;
}

/* Feature Cards */
.feature-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: 12px; padding: 20px; transition: all 0.3s;
}
.feature-card:hover { border-color: var(--accent); transform: translateY(-2px); }

/* Footer */
.app-footer { border-top: 1px solid var(--border-color); }

/* Responsive */
@media (max-width: 768px) {
  .btn-home span { display: none; }
  .brand-badge { display: none; }
  .preview-body { height: 300px; }
}