/* Main container */
.container {
    display: flex;
    gap: 12px;
    margin-top: 10px; /* Small gap between header and columns */
    height: calc(100vh - 109px); /* 10px body top + 84px header + 10px gap + 5px body bottom */
    padding: 0; /* Remove extra padding to avoid bottom blank space */
}

.column {
    flex: 1;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: flex 0.25s ease;
}

.column-header {
    padding: 12px 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
    overflow: hidden;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* First column - enhanced contrast gradient */
.column:nth-child(1) .column-header {
    background: linear-gradient(90deg, #f0f4f8 0%, #d0dce8 100%);
}

/* Second column - light purple gradient */
.column:nth-child(2) .column-header {
    background: linear-gradient(90deg, rgba(180, 160, 220, 0.12), rgba(160, 130, 220, 0.28));
}

/* Third column - yellow */
.column:nth-child(3) .column-header {
    background: linear-gradient(90deg, rgba(255, 193, 7, 0.1), rgba(255, 193, 7, 0.2));
}

/* Fourth column - red */
.column:nth-child(4) .column-header {
    background: linear-gradient(90deg, rgba(220, 53, 69, 0.1), rgba(220, 53, 69, 0.2));
}

/* Match column body background to header background */
.column:nth-child(1) {
    background: linear-gradient(90deg, #f0f4f8 0%, #d0dce8 100%);
}

.column:nth-child(2) {
    background: linear-gradient(90deg, rgba(180, 160, 220, 0.12), rgba(160, 130, 220, 0.28));
}

.column:nth-child(3) {
    background: linear-gradient(90deg, rgba(255, 193, 7, 0.1), rgba(255, 193, 7, 0.2));
}

.column:nth-child(4) {
    background: linear-gradient(90deg, rgba(220, 53, 69, 0.1), rgba(220, 53, 69, 0.2));
}

.column-header-content {
    display: flex;
    align-items: center;
    gap: 10px;
    position: relative;
    z-index: 2;
}

.column-header h2 {
    font-size: 14px;
    font-weight: 600;
    color: #333;
    letter-spacing: 0.5px;
}

.resize-icon {
    color: #888;
    font-size: 12px;
    cursor: ew-resize;
    padding: 4px;
    border-radius: 4px;
    transition: all 0.3s ease;
    position: relative;
    z-index: 2;
}

.scroll-container {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
    /* Thin, themed scrollbar (Firefox) */
    scrollbar-width: thin;
    scrollbar-color: rgba(120, 120, 120, 0.5) rgba(255, 255, 255, 0.2);
}

/* Thin, themed scrollbar (WebKit) */
.scroll-container::-webkit-scrollbar {
    width: 6px;
}

.scroll-container::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
}

.scroll-container::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, rgba(120, 120, 120, 0.5), rgba(80, 80, 80, 0.5));
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.35);
}

.scroll-container::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, rgba(120, 120, 120, 0.7), rgba(80, 80, 80, 0.7));
}

/* Responsive adjustments */
@media (max-width: 1024px) {
    .container {
        flex-wrap: wrap;
    }
    .column {
        min-width: calc(50% - 6px);
    }
}

@media (max-width: 768px) {
    .column {
        min-width: 100%;
    }
    .checkboxes {
        display: none;
    }
}