:root {
    --bg-color: #f4f7f6;
    --text-color: #333;
    --column-bg: #ebedf0;
    --card-bg: #ffffff;
    --primary-color: #007bff;
    --danger-color: #dc3545;
    --shadow: 0 2px 5px rgba(0,0,0,0.1);
    --border-radius: 8px;
    
    --low-priority: #28a745;
    --medium-priority: #ffc107;
    --high-priority: #dc3545;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #f4f4f4;
    --column-bg: #2d2d2d;
    --card-bg: #3d3d3d;
    --primary-color: #375a7f;
    --shadow: 0 2px 10px rgba(0,0,0,0.5);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    line-height: 1.6;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--card-bg);
    box-shadow: var(--shadow);
}

.header-actions button {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-color);
    cursor: pointer;
    transition: transform 0.2s;
}

.header-actions button:hover {
    transform: scale(1.1);
}

main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.add-task-container {
    display: flex;
    gap: 10px;
    margin-bottom: 2rem;
    background: var(--card-bg);
    padding: 1rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.add-task-container input {
    flex: 1;
    padding: 0.5rem 1rem;
    border: 1px solid #ccc;
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-color);
}

.add-task-container select {
    padding: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-color);
}

.add-task-container button {
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: opacity 0.2s;
}

.add-task-container button:hover {
    opacity: 0.9;
}

.board {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    align-items: start;
}

.column {
    background-color: var(--column-bg);
    border-radius: var(--border-radius);
    min-height: 500px;
    display: flex;
    flex-direction: column;
    padding: 10px;
}

.column-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    margin-bottom: 10px;
}

.task-count {
    background: #ccc;
    color: #333;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: bold;
}

.task-list {
    flex: 1;
    min-height: 100px;
}

.task-card {
    background-color: var(--card-bg);
    border-radius: 6px;
    padding: 15px;
    margin-bottom: 10px;
    box-shadow: var(--shadow);
    cursor: grab;
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
    border-left: 5px solid transparent;
}

.task-card:active {
    cursor: grabbing;
}

.task-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.task-card.priority-low { border-left-color: var(--low-priority); }
.task-card.priority-medium { border-left-color: var(--medium-priority); }
.task-card.priority-high { border-left-color: var(--high-priority); }

.task-content {
    margin-right: 30px;
    word-break: break-word;
}

.task-actions {
    position: absolute;
    top: 10px;
    right: 10px;
    display: flex;
    gap: 5px;
}

.task-actions button {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
    color: #888;
    transition: color 0.2s;
}

.task-actions .delete-btn:hover { color: var(--danger-color); }
.task-actions .edit-btn:hover { color: var(--primary-color); }

.dragging {
    opacity: 0.5;
    transform: scale(0.95);
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .board {
        grid-template-columns: 1fr;
    }
    
    .add-task-container {
        flex-direction: column;
    }
}