:root {
    /* 다크 모던 테마 - 기본값 */
    --bg-color: #0d0d0f;
    --bg-secondary: #16161a;
    --bg-card: #1a1a1f;
    --bg-card-hover: #242429;
    --text-color: #f0f0f0;
    --text-muted: #a0a0a0;
    --border-color: #2a2a2f;
    --accent-primary: #6366f1;
    --accent-secondary: #818cf8;
    --accent-glow: rgba(99, 102, 241, 0.15);
    --grid-gap: 16px;
    --transition-speed: 0.5s;
    --cubic-bezier: cubic-bezier(0.34, 1.56, 0.64, 1);

    /* 태그 색상 */
    --tag-bg: #2a2a35;
    --tag-text: #d0d0d0;
}

[data-theme="light"] {
    --bg-color: #f5f6f8;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f0f0f5;
    --text-color: #1a1a1a;
    --text-muted: #4b5563;
    --border-color: #d1d5db;
    --accent-primary: #4f46e5;
    --accent-secondary: #6366f1;
    --accent-glow: rgba(79, 70, 229, 0.1);

    /* 태그 색상 - 라이트 모드 */
    --tag-bg: #e8eaef;
    --tag-text: #374151;
}

body {
    margin: 0;
    padding: 20px;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    background-image:
        radial-gradient(ellipse at top, var(--accent-glow) 0%, transparent 50%),
        radial-gradient(ellipse at bottom right, rgba(99, 102, 241, 0.05) 0%, transparent 50%);
}

/* Site Header */
.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 0 20px 20px 20px;
    box-sizing: border-box;
}

.site-title {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-color);
}

.site-title .accent-text {
    color: var(--accent-primary);
}

h1 {
    text-align: center;
    margin: 40px 0 24px 0;
    font-weight: 300;
    letter-spacing: -1px;
    font-size: 2rem;
}

/* Category Tabs */
.category-tabs {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin: 0 auto 20px auto;
    max-width: 800px;
    flex-wrap: wrap;
    padding: 0 20px;
}

.category-tab {
    padding: 8px 18px;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-muted);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.category-tab:hover {
    color: var(--text-color);
    background: var(--bg-card-hover);
}

.category-tab.active {
    background: var(--accent-primary);
    color: #ffffff;
}

/* Tab visibility classes */
.tab-mobile-only {
    display: none;
}

.tab-desktop-only {
    display: inline-block;
}

.theme-toggle {
    background: var(--bg-secondary);
    border: none;
    color: var(--text-muted);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    z-index: 100;
    transition: all 0.3s ease;
    font-size: 0.8rem;
}

.theme-toggle:hover {
    background: var(--bg-card-hover);
    color: var(--text-color);
}

/* Content Container */
.content-container {
    flex: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    display: flex;
    flex-direction: column;
}

/* View Sections - CSS 트랜지션 */
.view-section {
    display: none;
    opacity: 0;
}

.view-section.active {
    display: block;
    animation: fadeIn 0.25s ease forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

/* Extras Container (for side-by-side on desktop) */
#extras-container {
    display: block;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    width: 100%;
    max-width: 900px;
    margin: 0 auto 60px auto;
    padding: 10px 24px 0 24px;
    box-sizing: border-box;
    position: relative;
}

.card {
    position: relative;
    aspect-ratio: 1;
    background-color: var(--bg-card);
    border-radius: 16px;
    padding: 20px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    overflow: hidden;
    color: var(--text-color);
    border: none;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--card-accent-1, var(--accent-primary)), var(--card-accent-2, var(--accent-secondary)));
    border-radius: 16px 16px 0 0;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
    background-color: var(--bg-card-hover, #242429);
    z-index: 1;
}

.card-title {
    font-size: 1.4rem;
    font-weight: bold;
    margin-bottom: 12px;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.tag {
    font-size: 0.8rem;
    padding: 5px 12px;
    background-color: var(--tag-bg);
    border: none;
    border-radius: 6px;
    color: var(--tag-text);
    font-weight: 500;
    letter-spacing: 0.01em;
    position: relative;
    cursor: default;
}

/* 태그 툴팁 - JS로 위치 계산 */
.tag-tooltip {
    position: fixed;
    background: var(--text-color);
    color: var(--bg-color);
    font-size: 0.75rem;
    font-weight: 400;
    padding: 8px 12px;
    border-radius: 6px;
    white-space: normal;
    width: max-content;
    max-width: min(250px, 90vw);
    line-height: 1.4;
    text-align: center;
    z-index: 9999;
    pointer-events: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity 0.15s ease;
}

.tag-tooltip.visible {
    opacity: 1;
}

/* Detail View */
.detail-view {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 50;
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s;
    padding: 20px;
    box-sizing: border-box;
}

.detail-card .tag {
    background-color: var(--tag-bg);
    border: none;
    color: var(--tag-text);
}

.detail-view.active {
    pointer-events: auto;
    opacity: 1;
}

.detail-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
}

.detail-card {
    position: relative;
    width: 100%;
    max-width: 500px;
    max-height: 85vh;
    background: var(--bg-card);
    border-radius: 20px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
    display: flex;
    flex-direction: column;
    padding: 30px;
    color: var(--text-color);
    overflow-y: auto;
    box-sizing: border-box;
    border: none;
}

.detail-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--card-accent-1, var(--accent-primary)), var(--card-accent-2, var(--accent-secondary)));
    border-radius: 20px 20px 0 0;
}

/* Custom Scrollbar for detail card */
.detail-card::-webkit-scrollbar {
    width: 8px;
}

.detail-card::-webkit-scrollbar-thumb {
    background-color: rgba(0, 0, 0, 0.2);
    border-radius: 4px;
}

.detail-content {
    margin-top: 20px;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.4s 0.2s, transform 0.4s 0.2s;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.detail-view.active .detail-content {
    opacity: 1;
    transform: translateY(0);
}

.description {
    font-size: 1.05rem;
    line-height: 1.7;
    white-space: pre-wrap;
    margin-bottom: 20px;
    color: var(--text-color);
}

/* Button Container */
.detail-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    margin-bottom: 20px;
}

/* Related Links Container */
.detail-related-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    /* 2 Columns */
    gap: 10px;
    width: 100%;
}

.related-btn {
    display: block;
    width: 100%;
    padding: 12px;
    font-size: 0.95rem;
    font-weight: 500;
    text-align: center;
    background: var(--bg-secondary);
    color: var(--text-color);
    border-radius: 10px;
    text-decoration: none;
    border: none;
    transition: all 0.2s ease;
    box-sizing: border-box;
}

.related-btn:hover {
    background: var(--bg-card-hover);
    transform: translateY(-1px);
}

.btn {
    padding: 12px 24px;
    font-size: 1.1rem;
    font-weight: bold;
    background: linear-gradient(135deg, var(--card-accent-1, var(--accent-primary)), var(--card-accent-2, var(--accent-secondary)));
    color: #ffffff;
    border-radius: 12px;
    text-decoration: none;
    transition: all 0.2s ease;
    border: none;
    width: 100%;
    text-align: center;
    display: block;
}

.btn:hover {
    filter: brightness(1.15);
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    color: inherit;
    padding: 5px;
    z-index: 10;
    opacity: 0.7;
    transition: opacity 0.2s, transform 0.2s;
}

.close-btn:hover {
    opacity: 1;
    transform: scale(1.1);
}

/* Server Section */
.server-section {
    width: 100%;
}

.server-section h2 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    text-align: center;
}

/* Utility Section - CSS 트랜지션 */
.utility-section {
    width: 100%;
    padding-bottom: 20px;
    opacity: 0;
}

.utility-section:not(.active) {
    display: none;
}

.utility-section.active {
    animation: fadeIn 0.25s ease forwards;
}

.utility-section h2 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    text-align: center;
}

.utility-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    /* 2 columns mobile default as requested */
    gap: 16px;
}

.utility-card {
    position: relative;
    background-color: var(--bg-card);
    border-radius: 14px;
    padding: 20px;
    text-decoration: none;
    color: var(--text-color);
    transition: transform 0.2s, box-shadow 0.2s, background-color 0.2s;
    border: none;
    display: flex;
    flex-direction: column;
    overflow: visible;
}

.utility-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--card-accent-1, var(--accent-primary)), var(--card-accent-2, var(--accent-secondary)));
    border-radius: 14px 14px 0 0;
}

/* New Header for Name + Tags alignment */
.utility-header {
    display: flex;
    flex-direction: column;
    /* Default stack on desktop if needed, or row */
    align-items: flex-start;
    margin-bottom: 8px;
    width: 100%;
}

.utility-name {
    font-weight: bold;
    font-size: 1.1rem;
    /* margin-bottom removed as it's handled by header gap or flex */
    margin-bottom: 4px;
}

.utility-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.25);
    background-color: var(--bg-card-hover);
}

.utility-name {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.utility-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Footer */
footer {
    text-align: center;
    padding: 15px 0 10px 0;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: auto;
}

/* Desktop Responsive */
@media (min-width: 601px) {
    body {
        min-height: 100vh;
        padding: 15px;
    }

    .content-container {
        flex: 1;
        padding-bottom: 10px;
    }

    .tab-mobile-only {
        display: none;
    }

    .tab-desktop-only {
        display: inline-block;
    }

    #extras-container {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 40px;
        max-width: 1200px;
        margin: 0 auto;
    }

    .utility-section {
        max-width: none;
        margin: 0;
        padding-bottom: 0;
    }

    .utility-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .card {
        aspect-ratio: 2;
        padding: 16px;
    }

    .grid-container {
        gap: 20px;
        margin-bottom: 15px;
        padding: 5px 32px 0 32px;
    }

    h1 {
        margin: 10px 0 10px 0;
        font-size: 1.8rem;
    }

    .site-header {
        padding: 0 32px 10px 32px;
    }

    .category-tabs {
        margin-bottom: 10px;
    }
}

/* Mobile Responsive */
@media (max-width: 600px) {
    .tab-mobile-only {
        display: inline-block;
    }

    .tab-desktop-only {
        display: none;
    }

    #extras-container {
        display: block;
    }

    .utility-section {
        display: none;
    }

    .utility-section.active {
        display: block;
    }

    h1 {
        font-size: 1.5rem;
        margin: 15px 0 15px 0;
    }

    .site-header {
        padding: 10px 16px 0 16px;
        margin-bottom: 15px;
    }

    .site-title {
        font-size: 1.5rem;
    }

    .category-tabs {
        gap: 6px;
        margin-bottom: 15px;
        padding: 0 10px;
    }

    .category-tab {
        padding: 6px 12px;
        font-size: 0.85rem;
    }

    .grid-container {
        grid-template-columns: 1fr;
        /* 1 column on mobile */
        gap: 12px;
        padding: 0 16px;
    }

    .card {
        padding: 14px;
        aspect-ratio: auto;
        /* Remove fixed aspect ratio */
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        gap: 10px;
    }

    .card-title {
        font-size: 1rem;
        margin-bottom: 0;
        flex-shrink: 0;
        white-space: nowrap;
    }

    /* Show tags on mobile, aligned to right */
    .card .tag {
        display: inline-block;
        font-size: 0.75rem;
        padding: 4px 10px;
        white-space: nowrap;
    }

    .card .card-tags {
        display: flex;
        justify-content: flex-end;
        flex-wrap: wrap;
        gap: 3px;
        row-gap: 3px;
    }

    /* Adjust detail view for mobile */
    .detail-card {
        padding: 24px;
        max-height: 90vh;
    }

    /* Ensure tags are visible in detail view on mobile */
    .detail-card .tag {
        display: inline-block;
    }

    .detail-card .card-tags {
        display: flex;
    }

    .utility-grid {
        grid-template-columns: 1fr;
        /* 1 column on mobile */
    }

    .utility-header {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 8px;
    }

    .utility-header .utility-name {
        margin-bottom: 0;
        margin-right: 10px;
    }

    .utility-header .card-tags {
        display: flex;
        /* Show tags on mobile utility cards */
        justify-content: flex-end;
    }
}