:root {
    --primary-color: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #0ea5e9;
    --light-bg: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --border-radius: 16px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

body {
    font-family: 'Poppins', sans-serif;
    background: var(--light-bg);
    margin: 0;
    padding: 0;
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

#container {
    width: 90%;
    max-width: 1200px;
    background: var(--card-bg);
    box-shadow: var(--shadow-lg);
    border-radius: var(--border-radius);
    overflow: hidden;
    margin: 2rem 0;
    transform: translateY(0);
    transition: var(--transition);
}

header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 2.5rem 2rem;
    position: relative;
    text-align: center;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxMjAwIiBoZWlnaHQ9IjMwMCI+PHBhdGggZmlsbD0ibm9uZSIgc3Ryb2tlPSIjZmZmZmZmMzAiIHN0cm9rZS13aWR0aD0iMiIgZD0iTTUgODAgUSAxMDAgMTAgMjAwIDgwIFQgNDAwIDgwIFQgNjAwIDgwIFQgODAwIDgwIFQgMTAwMCA4MCBUIDEyMDAgODAiLz48cGF0aCBmaWxsPSJub25lIiBzdHJva2U9IiNmZmZmZmYyMCIgc3Ryb2tlLXdpZHRoPSIyIiBkPSJNNSAxMDAgUSAxMDAgMzAgMjAwIDEwMCBUIDQwMCAxMDAgVCA2MDAgMTAwIFQgODAwIDEwMCBUIDEwMDAgMTAwIFQgMTIwMCAxMDAiLz48L3N2Zz4=') no-repeat center center;
    background-size: cover;
    opacity: 0.4;
    z-index: 0;
}

header h1 {
    margin: 0;
    font-size: 2.8rem;
    font-weight: 700;
    position: relative;
    z-index: 1;
    letter-spacing: 0.5px;
}

header p {
    margin: 10px 0 0;
    font-size: 1.2rem;
    font-weight: 400;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

main {
    padding: 2.5rem;
}

.tree-links {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    width: 100%;
    margin: 0 auto;
}

.tree-links li {
    width: 100%;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    overflow: hidden;
    background: var(--card-bg);
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    transform: translateY(0);
}

.tree-links li:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tree-links li a {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    padding: 1.5rem;
    color: var(--text-primary);
    font-size: 1.2rem;
    font-weight: 600;
    height: 100%;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.tree-links li:nth-child(1) {
    background: linear-gradient(45deg, rgba(37, 99, 235, 0.08), rgba(37, 99, 235, 0.02));
}

.tree-links li:nth-child(2) {
    background: linear-gradient(45deg, rgba(14, 165, 233, 0.08), rgba(14, 165, 233, 0.02));
}

.tree-links li:nth-child(3) {
    background: linear-gradient(45deg, rgba(79, 70, 229, 0.08), rgba(79, 70, 229, 0.02));
}

.tree-links li:nth-child(4) {
    background: linear-gradient(45deg, rgba(236, 72, 153, 0.08), rgba(236, 72, 153, 0.02));
}

.tree-links li:nth-child(5) {
    background: linear-gradient(45deg, rgba(249, 115, 22, 0.08), rgba(249, 115, 22, 0.02));
}

.tree-links li:nth-child(6) {
    background: linear-gradient(45deg, rgba(34, 197, 94, 0.08), rgba(34, 197, 94, 0.02));
}

.tree-links .icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    display: block;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: center;
    will-change: transform;
}

.tree-links li:nth-child(1) .icon {
    color: var(--primary-color);
}

.tree-links li:nth-child(2) .icon {
    color: var(--accent-color);
}

.tree-links li:nth-child(3) .icon {
    color: #4f46e5;
}

.tree-links li:nth-child(4) .icon {
    color: #ec4899;
}

.tree-links li:nth-child(5) .icon {
    color: #f97316;
}

.tree-links li:nth-child(6) .icon {
    color: #22c55e;
}

.tree-links li:hover .icon {
    transform: translateX(20px);
    position: relative;
}

.tree-links .tree-desc {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    line-height: 1.4;
}

footer {
    background: var(--light-bg);
    color: var(--text-secondary);
    padding: 1.5rem;
    text-align: center;
    font-size: 0.9rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

footer p {
    margin: 5px 0;
}

footer p:first-child {
    font-weight: 600;
    color: var(--text-primary);
}

.team-members {
    font-style: italic;
    display: inline-block;
    position: relative;
}

.team-members:after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    bottom: -2px;
    left: 0;
    background-color: var(--primary-light);
    opacity: 0.5;
    border-radius: 2px;
}

/* Responsive Design */
@media (max-width: 992px) {
    .tree-links {
        grid-template-columns: repeat(2, 1fr);
    }

    header h1 {
        font-size: 2.4rem;
    }
}

@media (max-width: 768px) {
    #container {
        width: 95%;
        margin: 1rem 0;
    }

    main {
        padding: 1.5rem;
    }

    header {
        padding: 2rem 1.5rem;
    }

    header h1 {
        font-size: 2rem;
    }

    header p {
        font-size: 1rem;
    }
}

@media (max-width: 576px) {
    .tree-links {
        grid-template-columns: 1fr;
    }

    header h1 {
        font-size: 1.8rem;
    }

    main {
        padding: 1.2rem;
    }
}