#board-container {
        background-color: #ffffff;
        color: #1a1a1a;
        width: 100%;
        position: relative;
        z-index: 50;
        padding-bottom: 80px;
        transition: background-color 0.3s, color 0.3s;
    }
    
    body.theme-dark #board-container, 
    body.theme-midnight #board-container {
        background-color: #000000 !important;
        color: #e5e5e5 !important;
    }

    /* [수정됨] Grid Layout (모바일 2단 보장) */
    .masonry-grid {
        display: grid;
        /* 기본(모바일): 2열 고정, 간격 좁게 */
        grid-template-columns: repeat(2, 1fr); 
        gap: 10px; 
        width: 100%;
    }

    /* 태블릿/PC: 화면 크기에 따라 자동 조절 (최소 200px) */
    @media (min-width: 640px) {
        .masonry-grid {
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 16px;
        }
    }

    /* Grid Item */
    .masonry-item {
        background: #ffffff;
        border: 1px solid rgba(0,0,0,0.08);
        border-radius: 16px;
        overflow: hidden;
        position: relative;
        cursor: pointer;
        transition: transform 0.2s, box-shadow 0.2s;
        display: flex;       
        flex-direction: column;
        height: 100%;        
    }

    body.theme-dark .masonry-item, body.theme-midnight .masonry-item {
        border-color: rgba(255,255,255,0.15) !important;
        background: #111111 !important;
    }

    .masonry-item:hover {
        transform: translateY(-3px);
        box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    }

    /* Badge & Text */
    .badge-hot {
        position: absolute; top: 6px; left: 6px; z-index: 10;
        background: linear-gradient(45deg, #ff4b1f, #ff9068);
        color: white; font-size: 9px; font-weight: bold;
        padding: 2px 6px; border-radius: 99px;
    }
    .txt-primary { color: #111; }
    .txt-sub { color: #6b7280; }
    body.theme-dark .txt-primary, body.theme-midnight .txt-primary { color: #fff !important; }
    body.theme-dark .txt-sub, body.theme-midnight .txt-sub { color: #9ca3af !important; }

    /* Navigation */
    .nav-icon-btn { width: 44px; height: 44px; display: flex; align-items: center; justify-content: center; border-radius: 12px; font-size: 20px; color: #888; transition: all 0.2s; background: transparent; }
    .nav-icon-btn.active { color: #000; background: rgba(0,0,0,0.05); transform: scale(1.1); }
    body.theme-dark .nav-icon-btn.active, body.theme-midnight .nav-icon-btn.active { color: #fff; background: rgba(255,255,255,0.1); }

    /* Modal */
    .modal-box { background-color: #ffffff; color: #111; border: 1px solid #e5e7eb; }
    body.theme-dark .modal-box, body.theme-midnight .modal-box { background-color: #1a1a1a !important; color: #fff !important; border: 1px solid rgba(255,255,255,0.1) !important; }
    
    .input-field { background-color: #f3f4f6; color: #111; border: 1px solid transparent; }
    body.theme-dark .input-field, body.theme-midnight .input-field { background-color: #262626 !important; color: #fff !important; border-color: rgba(255,255,255,0.1) !important; }

    /* Category */
    .cat-opt {
        display: flex; flex-direction: column; align-items: center; justify-content: center;
        gap: 4px; padding: 10px; border-radius: 12px;
        background: #f9fafb; color: #6b7280; border: 1px solid transparent;
        cursor: pointer; transition: all 0.2s;
    }
    body.theme-dark .cat-opt, body.theme-midnight .cat-opt { background: #262626; color: #9ca3af; border-color: #333; }
    
    .cat-opt.selected {
        background: #eff6ff; color: #2563eb; border-color: #2563eb;
    }
    body.theme-dark .cat-opt.selected, body.theme-midnight .cat-opt.selected {
        background: #1e3a8a !important; color: #60a5fa !important; border-color: #3b82f6 !important;
    }

    /* Icon Upload */
    .icon-upload-box {
        width: 80px; height: 80px; border-radius: 20px;
        background: #f3f4f6; border: 2px dashed #d1d5db;
        display: flex; align-items: center; justify-content: center;
        cursor: pointer; overflow: hidden; position: relative; margin: 0 auto;
    }
    body.theme-dark .icon-upload-box, body.theme-midnight .icon-upload-box { background: #262626; border-color: #444; }
    
    .loading-sentinel { width: 100%; height: 50px; margin-top: 10px; }
    
    .sticky-header { border-bottom: 1px solid #f3f4f6; background: #ffffff; }
    body.theme-dark .sticky-header, body.theme-midnight .sticky-header { border-bottom: 1px solid rgba(255,255,255,0.1); background: #000000; }

    /* API Box */
    .api-box { 
        background-color: #f9fafb; 
        border: 1px solid #e5e7eb; 
        border-radius: 12px;
        overflow: hidden;
        transition: all 0.3s ease;
    }
    body.theme-dark .api-box, 
    body.theme-midnight .api-box { 
        background-color: #1a1a1a !important; 
        border-color: rgba(255,255,255,0.1) !important; 
    }

    .api-header {
        padding: 12px;
        display: flex; 
        justify-content: space-between; 
        align-items: center;
        cursor: pointer;
        user-select: none;
        background-color: transparent;
    }
    body.theme-dark .api-header:hover,
    body.theme-midnight .api-header:hover {
        background-color: rgba(255,255,255,0.05);
    }

    .api-content {
        padding: 0 12px 12px 12px;
        border-top: 1px solid transparent;
    }
    .api-content.active {
        border-top-color: #e5e7eb;
    }
    body.theme-dark .api-content.active,
    body.theme-midnight .api-content.active {
        border-top-color: rgba(255,255,255,0.1);
    }