:root {
    --primary-color: #4a90e2;
    --text-color: #333;
    --bg-color: #fff;
    --card-bg: #f5f5f5;
    --header-bg: #fff;
    --footer-bg: #f5f5f5;
}

[data-theme="dark"] {
    --primary-color: #64b5f6;
    --text-color: #fff;
    --bg-color: #1a1a1a;
    --card-bg: #2d2d2d;
    --header-bg: #2d2d2d;
    --footer-bg: #2d2d2d;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s, color 0.3s;
}

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

header {
    background-color: var(--header-bg);
    padding: 20px 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 1.8rem;
    color: var(--primary-color);
}

.search-box {
    display: flex;
    gap: 10px;
}

#search {
    padding: 8px 15px;
    border: 1px solid #ddd;
    border-radius: 20px;
    width: 200px;
    font-size: 14px;
    background-color: var(--bg-color);
    color: var(--text-color);
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 5px;
}

main {
    padding: 40px 0;
}

.category {
    margin-bottom: 40px;
}

h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
}

.link-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    background-color: var(--card-bg);
    border-radius: 10px;
    text-decoration: none;
    color: var(--text-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.link-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.link-card i {
    font-size: 2rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.link-card span {
    font-size: 1rem;
    text-align: center;
}

footer {
    background-color: var(--footer-bg);
    padding: 20px 0;
    text-align: center;
    margin-top: 40px;
}

@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        gap: 15px;
    }

    .search-box {
        width: 100%;
    }

    #search {
        width: 100%;
    }

    .links-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
}