@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&display=swap');

:root {
    --primary: #6366f1;
    --primary-glow: rgba(99, 102, 241, 0.5);
    --secondary: #a855f7;
    --secondary-glow: rgba(168, 85, 247, 0.5);
    --accent: #22d3ee;
    --bg-dark: #020617;
    --card-bg: rgba(15, 23, 42, 0.6);
    --card-border: rgba(255, 255, 255, 0.08);
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    --glass-blur: 16px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Premium Mesh Gradient Background */
.mesh-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: var(--bg-dark);
    overflow: hidden;
}

.mesh-bg::before {
    content: '';
    position: absolute;
    width: 150%;
    height: 150%;
    top: -25%;
    left: -25%;
    background:
        radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 80% 70%, rgba(168, 85, 247, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 50% 50%, rgba(34, 211, 232, 0.05) 0%, transparent 50%);
    filter: blur(80px);
    animation: meshRotate 20s linear infinite;
}

@keyframes meshRotate {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* Advanced Glassmorphism */
.glass {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--card-border);
    border-radius: 24px;
    transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
    position: relative;
    overflow: hidden;
}

.glass-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, transparent 100%);
    pointer-events: none;
}

.glass-card:hover {
    transform: translateY(-8px);
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 20px var(--primary-glow);
}

/* Typography & Gradients */
.text-gradient {
    background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.primary-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.primary-gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Buttons */
.btn-premium {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 14px 32px;
    border-radius: 16px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px var(--primary-glow);
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.btn-premium:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px var(--primary-glow);
}

.btn-premium:active {
    transform: scale(0.98);
}

/* Mobile Optimizations */
@media (max-width: 640px) {
    .container {
        padding: 0 20px;
    }

    .glass-card {
        border-radius: 20px;
        padding: 20px !important;
    }

    h1 {
        font-size: 2rem !important;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(var(--primary), var(--secondary));
    border-radius: 10px;
}

/* Animations */
.animate-in {
    animation: slideUp 0.6s cubic-bezier(0.23, 1, 0.32, 1) forwards;
    opacity: 0;
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Module Specifics */
.test-option {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: 16px 20px;
    border-radius: 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    width: 100%;
    text-align: left;
    color: var(--text-main);
    margin-bottom: 12px;
}

.test-option:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--primary);
}

.test-option.selected {
    background: var(--primary-glow);
    border-color: var(--primary);
}

/* Flashcard Premium */
.flip-card {
    perspective: 2000px;
    height: 350px;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    transform-style: preserve-3d;
}

.flip-card.flipped .flip-card-inner {
    transform: rotateY(180deg);
}

.flip-card-front,
.flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 30px;
    text-align: center;
}

.flip-card-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(168, 85, 247, 0.2) 100%);
}