:root {
    --bg: #f6f8fb;
    --bg-secondary: #f8fafc;
    --card: #fff;
    --primary: #2563eb;
    --good: #16a34a;
    --bad: #ef4444;
    --muted: #64748b;
    --text: #0f172a;
    --border: #e2e8f0;
    --shadow: rgba(22, 28, 37, 0.06);
}

body {
    font-family: system-ui, Segoe UI, Roboto, Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 12px;
    transition: background 0.3s, color 0.3s;
}

body.dark-theme {
    --bg: #1e293b;
    --bg-secondary: #334155;
    --card: #475569;
    --primary: #3b82f6;
    --good: #22c55e;
    --bad: #ef4444;
    --muted: #94a3b8;
    --text: #f1f5f9;
    --border: #64748b;
    --shadow: rgba(0, 0, 0, 0.3);
}

.wrap {
    max-width: 1000px;
    margin: 0 auto;
}

.header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
}

.theme-controls {
    position: relative;
    display: flex;
    align-items: center;
    gap: 8px;
}

.theme-tooltip {
    font-size: 12px;
    color: var(--muted);
    background: var(--bg-secondary);
    padding: 4px 8px;
    border-radius: 4px;
    border: 1px solid var(--border);
}

.panel {
    background: var(--card);
    border-radius: 10px;
    padding: 12px;
    margin: 10px 0;
    box-shadow: 0 6px 18px var(--shadow);
    transition: background 0.3s, box-shadow 0.3s;
}

.row {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

.small {
    font-size: 13px;
    color: var(--muted);
}

textarea {
    width: 100%;
    min-height: 110px;
    padding: 8px;
    border-radius: 8px;
    border: 1px solid var(--border);
    font-size: 15px;
    resize: vertical;
    background: var(--card);
    color: var(--text);
    transition: background 0.3s, color 0.3s, border-color 0.3s;
}

button {
    padding: 8px 10px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-size: 14px;
    transition: background 0.2s, transform 0.1s;
}

button:active {
    transform: scale(0.98);
}

.btn-primary {
    background: var(--primary);
    color: #fff;
}

.btn-ghost {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--muted);
    transition: background 0.2s, border-color 0.2s;
}

.btn-ghost:hover {
    background: var(--bg-secondary);
}

select,
input[type=number],
input[type=range],
input[type=text] {
    padding: 6px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    transition: background 0.3s, color 0.3s, border-color 0.3s;
}

.card-box {
    background: linear-gradient(180deg, var(--card), var(--bg-secondary));
    padding: 18px;
    border-radius: 10px;
    min-height: 120px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    box-shadow: 0 10px 30px var(--shadow);
    transition: background 0.3s, box-shadow 0.3s;
}

#question {
    font-size: 18px;
    color: var(--text);
    line-height: 1.4;
}

#answer {
    margin-top: 10px;
    color: var(--primary);
    white-space: pre-wrap;
}

.controls {
    display: flex;
    gap: 8px;
    margin-top: 10px;
}

.controls button {
    flex: 1;
    padding: 12px;
    font-size: 16px;
    border-radius: 8px;
}

.btn-known {
    background: var(--good);
    color: #fff;
}

.btn-wrong {
    background: var(--bad);
    color: #fff;
}

.btn-show {
    background: var(--primary);
    color: #fff;
}

.status {
    margin-top: 8px;
    text-align: center;
    color: var(--muted);
    font-size: 14px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 8px;
    font-size: 13px;
}

th,
td {
    border: 1px solid var(--border);
    padding: 6px;
    text-align: left;
    vertical-align: middle;
    transition: border-color 0.3s;
}

input[type=text] {
    width: 100%;
}

@media (max-width:640px) {
    .controls {
        flex-direction: column;
    }
    .header-row {
        flex-direction: column;
        gap: 10px;
    }
    .theme-controls {
        flex-direction: column;
        align-items: flex-start;
    }
    .batch-actions {
        flex-direction: column;
        align-items: flex-start;
    }
    #selectedCount {
        margin-left: 0;
        margin-top: 8px;
    }
}

/* modal preview */
.modal {
    position: fixed;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.45);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.modal .box {
    width: 95%;
    max-width: 900px;
    background: var(--card);
    padding: 12px;
    border-radius: 8px;
    max-height: 85vh;
    overflow: auto;
    transition: background 0.3s;
}

.preview-table input {
    width: 100%;
    box-sizing: border-box;
}

.timer-warn {
    color: var(--bad);
    font-weight: 700;
}

/* 导入预览表格操作按钮样式 */
.preview-action-btn {
    padding: 4px 8px;
    font-size: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    transition: background 0.2s;
}

.preview-action-btn:hover {
    background: var(--bg);
}

/* 排序按钮样式 */
.sort-btn {
    padding: 2px 4px;
    font-size: 10px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 3px;
    cursor: pointer;
    margin: 0 1px;
    transition: background 0.2s;
    min-width: 20px;
}

.sort-btn:hover {
    background: var(--bg);
}

.sort-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 拖动样式 */
.dragging {
    opacity: 0.5;
    background: var(--primary);
    color: white;
}

.drag-over {
    border-top: 2px solid var(--primary);
}

/* 多选操作区域 */
.batch-actions {
    background: var(--bg-secondary);
    padding: 8px;
    border-radius: 6px;
    margin-bottom: 10px;
    border: 1px solid var(--border);
}

/* 选中计数 */
#selectedCount {
    font-weight: 600;
    color: var(--primary);
}

/* 卡片行选中状态 */
.card-row.selected {
    background: var(--primary);
    color: white;
}

.card-row.selected input,
.card-row.selected .sort-btn {
    background: rgba(255, 255, 255, 0.9);
    color: var(--text);
}

/* 移动端表格优化 */
@media (max-width: 768px) {
    table {
        font-size: 12px;
    }
    
    th, td {
        padding: 4px;
    }
    
    #cardTable th:nth-child(2),
    #cardTable td:nth-child(2) {
        width: 45px;
        min-width: 45px;
    }
    
    .sort-btn {
        padding: 1px 3px;
        font-size: 9px;
        margin: 0 1px;
    }
    
    .batch-actions button {
        padding: 6px 8px;
        font-size: 12px;
    }
    
    #cardTable th:nth-child(3),
    #cardTable td:nth-child(3),
    #cardTable th:nth-child(4),
    #cardTable td:nth-child(4) {
        min-width: 100px;
    }
}

@media (max-width: 480px) {
    table {
        font-size: 11px;
    }
    
    #cardTable th:nth-child(2),
    #cardTable td:nth-child(2) {
        width: 40px;
        min-width: 40px;
    }
    
    .sort-btn {
        padding: 1px 2px;
        font-size: 8px;
    }
    
    #cardTable th:nth-child(3),
    #cardTable td:nth-child(3),
    #cardTable th:nth-child(4),
    #cardTable td:nth-child(4) {
        min-width: 80px;
    }
}