/**
 * MyCityBiz Learn — Futuristic Design System
 * Pure CSS3 with Dark and Light Mode Support
 */

:root {
    --bg-primary: #090d16;
    --bg-secondary: #0f172a;
    --bg-card: rgba(15, 23, 42, 0.75);
    --bg-card-hover: rgba(30, 41, 59, 0.8);
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-active: rgba(6, 182, 212, 0.4);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-cyan: #06b6d4;
    --accent-cyan-glow: rgba(6, 182, 212, 0.25);
    --accent-violet: #8b5cf6;
    --accent-emerald: #10b981;
    --accent-amber: #f59e0b;
    --accent-rose: #f43f5e;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    --glass-blur: blur(16px);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 9999px;
    --shadow-glow: 0 0 25px rgba(6, 182, 212, 0.15);
}

[data-theme="light"] {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: rgba(255, 255, 255, 0.9);
    --bg-card-hover: rgba(241, 245, 249, 1);
    --border-subtle: rgba(0, 0, 0, 0.08);
    --border-active: rgba(6, 182, 212, 0.6);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --shadow-glow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: inherit;
    text-decoration: none;
}

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

/* Glassmorphism Surface */
.glass-panel {
    background: var(--bg-card);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-violet));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Futuristic Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(9, 13, 22, 0.85);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border-subtle);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
    list-style: none;
}

.nav-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.15s ease;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
}

.btn-glow {
    background: linear-gradient(135deg, var(--accent-cyan), #3b82f6);
    color: #ffffff;
    box-shadow: 0 0 15px var(--accent-cyan-glow);
}

.btn-glow:hover {
    filter: brightness(1.15);
    transform: translateY(-1px);
    box-shadow: 0 0 25px rgba(6, 182, 212, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--border-active);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.8rem;
    border-radius: var(--radius-sm);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.2px;
}

.badge-cyan { background: rgba(6, 182, 212, 0.15); color: var(--accent-cyan); border: 1px solid rgba(6, 182, 212, 0.3); }
.badge-violet { background: rgba(139, 92, 246, 0.15); color: var(--accent-violet); border: 1px solid rgba(139, 92, 246, 0.3); }
.badge-emerald { background: rgba(16, 185, 129, 0.15); color: var(--accent-emerald); border: 1px solid rgba(16, 185, 129, 0.3); }
.badge-amber { background: rgba(245, 158, 11, 0.15); color: var(--accent-amber); border: 1px solid rgba(245, 158, 11, 0.3); }

/* Grid Layouts */
.grid-cols-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.grid-cols-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

@media (max-width: 900px) {
    .grid-cols-3 { grid-template-columns: repeat(2, 1fr); }
    .nav-links { display: none; }
}

@media (max-width: 640px) {
    .grid-cols-3, .grid-cols-2 { grid-template-columns: 1fr; }
}