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

:root {
    --primary-color: #1a1a2e;
    --secondary-color: #4a5568;
    --accent-color: #2d3748;
    --background-color: #f7f8fa;
    --card-background: #ffffff;
    --text-color: #1a1a2e;
    --text-light: #718096;
    --border-color: #e2e8f0;
    --hover-color: #2b6cb0;
    --border-radius: 8px;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] {
    --primary-color: #e2e8f0;
    --secondary-color: #a0aec0;
    --accent-color: #cbd5e0;
    --background-color: #0f1419;
    --card-background: #1a1f26;
    --text-color: #e2e8f0;
    --text-light: #a0aec0;
    --border-color: #2d3748;
    --hover-color: #63b3ed;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.3), 0 2px 4px rgba(0, 0, 0, 0.2);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--background-color);
    min-height: 100vh;
    color: var(--text-color);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Utility */
.hidden {
    display: none;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    padding: 0 4px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

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

.site-logo {
    height: 32px;
    width: auto;
    object-fit: contain;
}

.site-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
}

.datetime {
    font-size: 0.95rem;
    color: var(--text-light);
    font-weight: 500;
}

.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--card-background);
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.15s ease;
    box-shadow: var(--shadow);
}

.theme-toggle:hover {
    background: var(--background-color);
    border-color: var(--text-light);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

.theme-toggle .icon-moon {
    display: none;
}

[data-theme="dark"] .theme-toggle .icon-sun {
    display: none;
}

[data-theme="dark"] .theme-toggle .icon-moon {
    display: block;
}

/* Message Banner */
.message-banner {
    background: var(--card-background);
    color: var(--text-color);
    padding: 14px 24px;
    border-radius: var(--border-radius);
    text-align: center;
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    animation: fadeIn 0.3s ease-out;
}

.message-banner:empty {
    display: none;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Main Content Layout */
.main-content {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 20px;
}

/* Links Section */
.links-section {
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.category {
    margin-bottom: 25px;
}

.category:last-child {
    margin-bottom: 0;
}

.category-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-light);
    font-weight: 600;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 10px;
}

.link-card {
    display: flex;
    align-items: center;
    padding: 10px 14px;
    background: var(--background-color);
    border-radius: 6px;
    text-decoration: none;
    color: var(--text-color);
    border: 1px solid transparent;
    transition: all 0.15s ease;
}

.link-card:hover {
    background: var(--card-background);
    color: var(--hover-color);
    border-color: var(--border-color);
    box-shadow: var(--shadow-lg);
}

.link-icon {
    width: 20px;
    height: 20px;
    margin-right: 10px;
    opacity: 0.7;
}

.link-card:hover .link-icon {
    opacity: 1;
}

.link-title {
    font-size: 0.95rem;
    font-weight: 500;
    display: flex;
    flex-direction: column;
    gap: 2px;
    overflow: hidden;
}

.link-date {
    font-size: 0.75rem;
    color: var(--text-light);
    font-weight: 400;
}

.loading-text, .error-text {
    font-size: 0.85rem;
    color: var(--text-light);
    padding: 8px;
}

.error-text {
    color: var(--accent-color);
}

/* RSS Section */
.rss-section {
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    height: fit-content;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
}

.rss-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
    color: var(--text-light);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.rss-item {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.rss-item:last-child {
    border-bottom: none;
}

.rss-item-title {
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 4px;
    line-height: 1.4;
}

.rss-item-title a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.15s ease;
}

.rss-item-title a:hover {
    color: var(--hover-color);
}

.rss-item-date {
    font-size: 0.8rem;
    color: var(--text-light);
}

.rss-item-description {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 8px;
    line-height: 1.4;
}

.loading, .error {
    text-align: center;
    padding: 20px;
    color: var(--text-light);
}

.error {
    color: var(--accent-color);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr 300px;
    }

    .links-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    }
}

@media (max-width: 768px) {
    .container {
        padding: 16px;
    }

    .main-content {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .rss-section {
        max-height: none;
        order: 2;
    }

    .links-section {
        order: 1;
    }

    .links-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 8px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 12px;
    }

    .datetime {
        display: none;
    }

    .site-name {
        font-size: 1rem;
    }

    .site-logo {
        height: 24px;
    }

    .message-banner {
        font-size: 0.9rem;
        padding: 12px 16px;
    }

    .links-section,
    .rss-section {
        padding: 16px;
    }

    .links-grid {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }

    .link-card {
        padding: 10px 12px;
        font-size: 0.9rem;
    }

    .link-title {
        font-size: 0.85rem;
    }

    .category {
        margin-bottom: 20px;
    }
}

@media (max-width: 360px) {
    .links-grid {
        grid-template-columns: 1fr;
    }
}