:root {
    --bg: #0f0f1a;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --card-bg: rgba(30,30,50,0.6);
    --card-border: rgba(99,102,241,0.25);
    --primary: #6366f1;
    --accent: #a78bfa;
    --success: #10b981;
    --navbar-bg: rgba(15,15,26,0.75);
}

[data-bs-theme="light"] {
    --bg: #f8fafc;
    --text: #1e293b;
    --text-muted: #64748b;
    --card-bg: rgba(255,255,255,0.75);
    --card-border: rgba(99,102,241,0.15);
    --primary: #4f46e5;
    --accent: #7c3aed;
    --success: #059669;
    --navbar-bg: rgba(248,250,252,0.85);
}

body {
    font-family: 'Poppins', sans-serif;
    background: var(--bg);
    color: var(--text);
    transition: background-color 0.4s, color 0.4s;
}

.navbar {
    backdrop-filter: blur(16px);
    background: var(--navbar-bg) !important;
    border-bottom: 1px solid var(--card-border);
}

.brand-glow {
    background: linear-gradient(90deg, var(--primary), var(--accent), var(--primary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    background-size: 200%;
    animation: shine 7s linear infinite;
}

@keyframes shine { 0%,100% {background-position:0%} 50% {background-position:200%} }

.hero { min-height: 90vh; position: relative; }
.hero-bg {
    position: absolute; inset: 0;
    background: radial-gradient(circle at 15% 20%, rgba(99,102,241,0.18), transparent 45%),
                radial-gradient(circle at 85% 75%, rgba(167,139,250,0.12), transparent 55%);
    pointer-events: none;
}

.code-float {
    position: absolute;
    font-family: 'Space Grotesk', monospace;
    color: rgba(99,102,241,0.3);
    pointer-events: none;
    animation: float 20s infinite ease-in-out;
    white-space: nowrap;
}

@keyframes float { 0%,100% {transform:translateY(0) rotate(0deg); opacity:0.3} 50% {transform:translateY(-220px) rotate(3deg); opacity:0.65} }

.card-course {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(10px);
    transition: all 0.35s;
}

.card-course:hover {
    transform: translateY(-10px);
    border-color: var(--accent);
    box-shadow: 0 20px 40px -10px rgba(99,102,241,0.25);
}

.badge-free {
    background: var(--success);
    font-size: 0.9rem;
    padding: 0.45rem 1.1rem;
}

.theme-toggle {
    font-size: 1.7rem;
    cursor: pointer;
    transition: all 0.4s;
}

.theme-toggle:hover {
    transform: rotate(25deg) scale(1.35);
    color: var(--accent) !important;
}

footer {
    background: linear-gradient(to top, rgba(15,15,26,0.9), transparent);
    border-top: 1px solid var(--card-border);
    padding: 4rem 0 2rem;
}

[data-bs-theme="light"] footer {
    background: linear-gradient(to top, rgba(248,250,252,0.9), transparent);
}

.btn-outline {
    margin-top: auto;
    margin-bottom: 0;
}