.kb-board {
    display: flex;
    gap: 16px;
    overflow-x: auto;
    padding: 8px 0 16px;
    justify-content: center;
    -webkit-overflow-scrolling: touch;
}

.kb-column {
    min-width: 250px;
    max-width: 280px;
    flex-shrink: 0;
    border-radius: 12px;
    background: color-mix(in srgb, var(--mud-palette-surface) 60%, var(--mud-palette-background));
    display: flex;
    flex-direction: column;
    border: 1.5px solid transparent;
    transition: border-color 0.15s, background 0.15s;
}

.kb-column-drop-active {
    border-color: var(--mud-palette-primary);
    background: color-mix(in srgb, var(--mud-palette-primary) 6%, var(--mud-palette-surface));
}

.kb-column-header {
    padding: 12px 14px 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.kb-column-header-title {
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--mud-palette-text-secondary);
}

.kb-column-count {
    font-size: 0.75rem;
    background: color-mix(in srgb, var(--mud-palette-text-secondary) 15%, transparent);
    border-radius: 99px;
    padding: 1px 8px;
    color: var(--mud-palette-text-secondary);
}

.kb-column-body {
    flex: 1;
    padding: 0 10px 10px;
    min-height: 120px;
}

.kb-card {
    background: var(--mud-palette-surface);
    border-radius: 8px;
    padding: 10px 12px;
    margin-bottom: 8px;
    cursor: grab;
    border: 1px solid color-mix(in srgb, var(--mud-palette-text-primary) 8%, transparent);
    transition: box-shadow 0.15s, opacity 0.15s, transform 0.15s;
    user-select: none;
    -webkit-user-select: none;
}

.kb-card:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.kb-card.kb-dragging {
    opacity: 0.4;
    transform: scale(0.97);
}

.kb-card-title {
    font-size: 0.84rem;
    font-weight: 500;
    color: var(--mud-palette-text-primary);
    line-height: 1.3;
}

.kb-card-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 6px;
    font-size: 0.72rem;
    color: var(--mud-palette-text-secondary);
}

.kb-card-due { display: flex; align-items: center; gap: 2px; }
.kb-card-due.kb-overdue { color: var(--mud-palette-error); }

.kb-priority-urgent { color: var(--mud-palette-error); }
.kb-priority-high { color: var(--mud-palette-warning); }

.kb-progress-bar {
    height: 4px;
    border-radius: 2px;
    background: color-mix(in srgb, var(--mud-palette-primary) 15%, transparent);
    margin-top: 6px;
    overflow: hidden;
}

.kb-progress-fill {
    height: 100%;
    border-radius: 2px;
    background: var(--mud-palette-primary);
    transition: width 0.3s;
}

.kb-add-task {
    padding: 6px 10px;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.82rem;
    color: var(--mud-palette-text-secondary);
    transition: background 0.15s;
}

.kb-add-task:hover {
    background: color-mix(in srgb, var(--mud-palette-text-primary) 6%, transparent);
}

.kb-add-form {
    padding: 0 10px 10px;
}

@media (max-width: 600px) {
    .kb-board { justify-content: flex-start; }
    .kb-column { min-width: 220px; }
}