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

:root {
    --primary: #0066ff;
    --primary-light: #e6f0ff;
    --white: #ffffff;
    --gray-50: #f8f9fa;
    --gray-100: #f1f3f5;
    --gray-300: #dee2e6;
    --gray-500: #868e96;
    --gray-700: #495057;
    --gray-900: #212529;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.12);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.6;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow);
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.logo {
    font-size: 20px;
    font-weight: 600;
    color: var(--gray-900);
    white-space: nowrap;
    min-width: 140px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
    justify-content: flex-end;
}

.bookmark-link {
    font-size: 14px;
    color: var(--primary);
    text-decoration: none;
    padding: 8px 12px;
    border: 2px solid var(--primary);
    border-radius: 8px;
    transition: all 0.2s;
    white-space: nowrap;
}

.bookmark-link:hover {
    background: var(--primary);
    color: var(--white);
}

.lang-select {
    padding: 8px 12px;
    border: 2px solid var(--gray-300);
    border-radius: 8px;
    font-size: 14px;
    background: var(--white);
    color: var(--gray-900);
    cursor: pointer;
    outline: none;
    transition: border-color 0.2s;
}

.lang-select:hover {
    border-color: var(--primary);
}

.lang-select:focus {
    border-color: var(--primary);
}

.search-box {
    display: flex;
    gap: 8px;
    flex: 1;
    max-width: 480px;
}

.search-box input {
    flex: 1;
    padding: 10px 16px;
    border: 2px solid var(--gray-300);
    border-radius: 8px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s;
}

.search-box input:focus {
    border-color: var(--primary);
}

.search-box button {
    padding: 10px 20px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
}

.search-box button:hover {
    background: #0052cc;
}

.category-nav {
    position: fixed;
    top: 65px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--gray-100);
    z-index: 99;
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 24px;
    display: flex;
    gap: 8px;
    overflow-x: auto;
}

.category-btn {
    padding: 8px 16px;
    background: var(--gray-50);
    color: var(--gray-700);
    border: none;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.category-btn:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.category-btn.active {
    background: var(--primary);
    color: var(--white);
}

.main {
    padding-top: 150px;
    padding-bottom: 60px;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.card {
    background: var(--white);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.card-category {
    display: inline-block;
    padding: 4px 10px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    margin-bottom: 12px;
    width: fit-content;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.card-desc {
    font-size: 14px;
    color: var(--gray-500);
    flex: 1;
    margin-bottom: 16px;
    line-height: 1.5;
}

.card-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    background: var(--primary);
    color: var(--white);
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: background 0.2s;
}

.card-link:hover {
    background: #0052cc;
}

.no-result {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray-500);
}

.footer {
    background: var(--white);
    border-top: 1px solid var(--gray-100);
    text-align: center;
    padding: 20px;
    color: var(--gray-500);
    font-size: 14px;
}

@media (max-width: 1024px) {
    .card-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 12px;
    }

    .search-box {
        max-width: 100%;
    }

    .main {
        padding-top: 140px;
    }

    .category-nav {
        top: 120px;
    }

    .card-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .card-grid {
        grid-template-columns: 1fr;
    }

    .nav-content {
        padding: 12px 16px;
    }

    .container {
        padding: 16px;
    }
}