/* ==========================================================================
   Backlog & Sprint Management Styles
   ========================================================================== */

.backlog-layout {
    display: flex;
    gap: 20px;
    height: 100%;
    padding: 20px;
    overflow: hidden;
}

/* Sprint Panel (Left) */
.sprint-panel {
    width: 320px;
    min-width: 280px;
    max-width: 350px;
    background-color: var(--bg-primary);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.sprint-list-header {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 4px;
    flex-wrap: nowrap;
}

.sprint-list-header h3 {
    margin: 0;
    font-size: 16px;
    font-weight: 600;
    white-space: nowrap;
    flex-shrink: 0;
}

.btn-new-sprint {
    padding: 6px 12px;
    margin-left: 8px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s;
    white-space: nowrap;
    flex-shrink: 0;
}

.btn-new-sprint:hover {
    background-color: #0056b3;
    opacity: 0.9;
}

.sprint-list {
    flex: 1;
    padding: 12px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* Sprint Card */
.sprint-card {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 12px;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.sprint-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transform: translateY(-1px);
}

.sprint-card.selected {
    border-color: var(--primary-color);
    border-width: 2px;
    background-color: rgba(37, 99, 235, 0.05);
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
}

.sprint-card.active {
    border-left: 4px solid #22c55e;
    padding-left: 10px;
}

.sprint-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 8px;
}

.sprint-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
    line-height: 1.4;
    word-break: break-word;
}

.sprint-status {
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    white-space: nowrap;
    flex-shrink: 0;
}

.sprint-status.planned {
    background-color: #e0e7ff;
    color: #4338ca;
}

.sprint-status.active {
    background-color: #dcfce7;
    color: #166534;
}

.sprint-status.completed {
    background-color: #f3f4f6;
    color: #6b7280;
}

.sprint-dates {
    font-size: 11px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.sprint-stats {
    display: flex;
    gap: 12px;
    margin-bottom: 8px;
}

.stat-item {
    font-size: 11px;
    display: flex;
    gap: 4px;
}

.stat-label {
    color: var(--text-secondary);
}

.stat-value {
    font-weight: 600;
    color: var(--text-primary);
}

.sprint-progress {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.sprint-actions {
    display: flex;
    gap: 6px;
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px solid var(--border-color);
}

.btn-icon {
    padding: 4px 8px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-icon:hover {
    background-color: var(--bg-tertiary);
    border-color: #999;
    transform: scale(1.05);
}

/* Velocity Chart */
.velocity-chart {
    padding: 16px;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
}

.velocity-chart h4 {
    margin: 0 0 12px 0;
    font-size: 14px;
    font-weight: 600;
}

.velocity-bars {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    height: 100px;
    margin-bottom: 12px;
}

.velocity-bar-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.velocity-bar {
    width: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 4px 4px 0 0;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 4px 2px;
    min-height: 20px;
    position: relative;
}

.velocity-value {
    font-size: 11px;
    font-weight: 600;
    color: white;
}

.velocity-label {
    font-size: 10px;
    color: var(--text-secondary);
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

.velocity-average {
    text-align: center;
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Backlog Panel (Right) */
.backlog-panel {
    flex: 1;
    background-color: var(--bg-primary);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.backlog-header {
    padding: 14px 16px;
    border-bottom: 2px solid var(--border-color);
    background-color: var(--bg-secondary);
}

.backlog-header h3 {
    margin: 0;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.backlog-tasks {
    flex: 1;
    padding: 16px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* Backlog Section */
.backlog-section {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.backlog-section-header {
    padding: 12px 16px;
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
}

.section-icon {
    font-size: 16px;
}

.section-label {
    flex: 1;
    font-size: 14px;
}

.section-count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    height: 20px;
    padding: 0 6px;
    background-color: var(--bg-primary);
    border-radius: 10px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-secondary);
}

.backlog-task-list {
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    min-height: 60px;
}

.backlog-task-list.drag-over {
    background-color: rgba(37, 99, 235, 0.05);
    border: 2px dashed var(--primary-color);
}

/* Backlog Task Card */
.backlog-task-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px;
    cursor: move;
    transition: all 0.2s;
}

.backlog-task-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--border-dark);
    transform: translateY(-2px);
}

.backlog-task-card.dragging {
    opacity: 0.4;
}

.task-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
}

.task-type {
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    color: white;
}

.task-priority {
    font-size: 16px;
}

.task-card-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.task-card-footer {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    font-size: 11px;
    color: var(--text-secondary);
}

.task-points,
.task-assignee,
.task-date {
    padding: 2px 6px;
    background-color: var(--bg-secondary);
    border-radius: 3px;
}

/* Unassigned Tasks */
.unassigned-tasks {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 2px solid var(--border-color);
}

.unassigned-tasks h4 {
    margin: 0 0 12px 0;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-secondary);
}

.backlog-task-list.unassigned {
    background-color: var(--bg-tertiary);
    border-radius: 8px;
}

/* Empty States */
.empty-state {
    padding: 60px 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 14px;
}

.empty-state-small {
    padding: 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 12px;
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 1024px) {
    .backlog-layout {
        flex-direction: column;
    }

    .sprint-panel {
        width: 100%;
        max-width: none;
        height: 300px;
    }

    .backlog-panel {
        flex: 1;
    }
}

@media (max-width: 768px) {
    .backlog-layout {
        padding: 12px;
    }

    .sprint-card {
        padding: 12px;
    }

    .velocity-bars {
        height: 80px;
    }
}