:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background: var(--bg-gradient);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    overflow-x: hidden;
}

.container {
    max-width: 1000px;
    width: 100%;
    text-align: center;
    position: relative;
    z-index: 1;
}

.container::before {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    z-index: -1;
    border-radius: 50%;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.activity-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.card-label {
    cursor: pointer;
    display: block;
    height: 100%;
}

.card-content {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 1.5rem;
    padding: 2.5rem 1.5rem;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.25rem;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.icon-wrapper {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 1rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
    transition: var(--transition);
}

.icon-wrapper lucide-icon {
    width: 32px;
    height: 32px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-main);
}

/* Hidden radio implementation */
input[type="radio"] {
    display: none;
}

input[type="radio"]:checked+.card-content {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--primary);
    transform: translateY(-8px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2), 0 10px 10px -5px rgba(0, 0, 0, 0.1);
}

input[type="radio"]:checked+.card-content .icon-wrapper {
    background: var(--primary);
    color: white;
    transform: scale(1.1);
}

.card-label:hover .card-content {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.08);
}

.submit-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 1rem 3rem;
    font-size: 1.125rem;
    font-weight: 600;
    border-radius: 9999px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 10px 15px -3px rgba(99, 102, 241, 0.3);
}

.submit-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 20px 25px -5px rgba(99, 102, 241, 0.4);
}

.submit-btn:active {
    transform: translateY(0);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .activity-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
    }

    h1 {
        font-size: 2rem;
        padding: 0 1rem;
    }
}

/* Success Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: rgba(30, 41, 59, 0.95);
    border: 1px solid var(--card-border);
    padding: 3rem;
    border-radius: 2rem;
    max-width: 400px;
    width: 90%;
    text-align: center;
    transform: scale(0.9);
    transition: var(--transition);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.success-icon {
    width: 80px;
    height: 80px;
    background: #10b981;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    box-shadow: 0 0 20px rgba(16, 185, 129, 0.4);
}

.modal-content h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.modal-content p {
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 2rem;
}

.close-btn {
    background: var(--primary);
    border: none;
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 9999px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.close-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}