/* ========== 菜单切换样式 ========== */
.menu-item {
    transition: all 0.3s ease;
}

.menu-item.active {
    background: linear-gradient(135deg, #7aa8d6, #5d8ab8);
    color: #ffffff;
    box-shadow: 6px 6px 12px #4a6fa5, -6px -6px 12px #a5c8e8;
}

/* ========== 卡片显示控制 ========== */
.exercise-card.hidden {
    display: none !important;
}

/* ========== 语法填空卡片样式 ========== */
/* 继承现有卡片基础样式 */

/* 语法填空引言横线容器 */
.grammar-quote-line {
    position: relative;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: -15px 0 15px 0;
}

/* 引言横线 */
.grammar-quote-line::before {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    top: 50%;
    height: 2px;
    background: rgba(173, 216, 230, 0.5);
    z-index: 1;
}

/* 语法填空引言区域 */
.grammar-quote {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 0 20px;
    background: linear-gradient(135deg, #e3edf7, #d4e6f9);
}

.grammar-quote .quote-mark {
    font-size: 18px;
    color: rgba(122, 168, 214, 0.5);
    font-family: 'Georgia', serif;
    line-height: 1;
    flex-shrink: 0;
}

.grammar-quote .quote-text {
    font-size: 13px;
    font-style: italic;
    color: #5d8ab8;
    font-weight: 500;
    letter-spacing: 0.3px;
    line-height: 1.4;
    white-space: nowrap;
}

.grammar-content {
    position: relative;
    z-index: 10;
    padding: 20px 0;
    min-height: 200px;
    -webkit-user-select: text;
    user-select: text;
}

.grammar-paragraph {
    margin-bottom: 24px;
    line-height: 2;
    font-size: 16px;
    color: #4a6fa5;
    position: relative;
    z-index: 5;
}

.grammar-sentence {
    display: inline;
    margin-right: 8px;
    -webkit-user-select: text;
    user-select: text;
    position: relative;
    z-index: 5;
}

.grammar-text {
    color: #4a6fa5;
    -webkit-user-select: text;
    user-select: text;
}

.grammar-number {
    color: #5d8ab8;
    font-weight: 600;
    margin: 0 0 0 8px;
    -webkit-user-select: text;
    user-select: text;
}

/* 语法填空输入框 */
.grammar-blank {
    display: inline-block;
    width: 80px;
    min-width: 80px;
    max-width: 200px;
    height: 24px;
    border: none;
    border-bottom: 2px solid rgba(93, 138, 184, 0.5);
    border-radius: 0;
    background: transparent;
    padding: 0 6px;
    margin: 0 4px;
    font-family: 'Nunito', sans-serif;
    font-size: 15px;
    font-weight: 500;
    color: #4a6fa5;
    text-align: left;
    -webkit-user-select: text;
    user-select: text;
    -webkit-touch-callout: text;
    cursor: text;
    box-sizing: border-box;
    line-height: 20px;
    vertical-align: middle;
    transition: none;
}

.grammar-hint {
    color: #7aa8d6;
    font-size: 15px;
    font-style: italic;
    margin: 0 2px;
    -webkit-user-select: text;
    user-select: text;
}

.grammar-blank:focus {
    outline: none;
    border-bottom-color: rgba(93, 138, 184, 0.6);
}

/* 正确状态 */
.grammar-blank.correct {
    border-bottom-color: rgba(40, 167, 69, 0.6);
    color: #155724;
}

/* 错误状态 */
.grammar-blank.incorrect {
    border-bottom-color: rgba(220, 53, 69, 0.6);
    color: #721c24;
}

.answers-list {
    margin-top: 10px;
    margin-bottom: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 40px;
    padding: 10px 15px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 8px;
    -webkit-user-select: text;
    user-select: text;
}

.answer-item {
    flex: 0 0 calc(50% - 20px);
    padding: 4px 8px;
    color: #4a6fa5;
    font-weight: 600;
    box-sizing: border-box;
    text-align: left;
    white-space: nowrap;
    -webkit-user-select: text;
    user-select: text;
}

.answer-spacer {
    display: inline-block;
    width: 60px;
}

/* 按钮禁用状态 */
.btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 响应式适配 */
@media (max-width: 768px) {
    .grammar-quote-line {
        height: 26px;
        margin: -13px 0 12px 0;
    }

    .grammar-quote {
        padding: 0 15px;
        gap: 4px;
    }

    .grammar-quote .quote-mark {
        font-size: 16px;
    }

    .grammar-quote .quote-text {
        font-size: 12px;
        letter-spacing: 0.2px;
        white-space: normal;
    }

    .grammar-content {
        padding: 15px 0;
    }

    .grammar-paragraph {
        font-size: 15px;
        line-height: 1.9;
        margin-bottom: 20px;
    }

    .grammar-blank {
        min-width: 70px !important;
        max-width: 180px !important;
        min-height: 22px !important;
        font-size: 14px !important;
        padding: 3px 5px 1px 5px !important;
        margin: 0 4px !important;
    }
}

@media (max-width: 480px) {
    .grammar-quote-line {
        height: 24px;
        margin: -12px 0 10px 0;
    }

    .grammar-quote {
        padding: 0 12px;
        gap: 3px;
    }

    .grammar-quote .quote-mark {
        font-size: 14px;
    }

    .grammar-quote .quote-text {
        font-size: 11px;
        letter-spacing: 0.1px;
        white-space: normal;
        line-height: 1.3;
    }

    .grammar-content {
        padding: 10px 0;
    }

    .grammar-paragraph {
        font-size: 14px;
        line-height: 1.8;
        margin-bottom: 16px;
    }

    .grammar-sentence {
        margin-right: 4px;
    }

    .grammar-blank {
        min-width: 60px !important;
        max-width: 160px !important;
        min-height: 20px !important;
        font-size: 13px !important;
        padding: 2px 4px 1px 4px !important;
        margin: 0 3px !important;
    }
}

@media (max-width: 360px) {
    .grammar-quote-line {
        height: 22px;
        margin: -11px 0 8px 0;
    }

    .grammar-quote {
        padding: 0 10px;
        gap: 2px;
    }

    .grammar-quote .quote-mark {
        font-size: 12px;
    }

    .grammar-quote .quote-text {
        font-size: 10px;
        letter-spacing: 0;
        white-space: normal;
        line-height: 1.2;
    }

    .grammar-paragraph {
        font-size: 13px;
        line-height: 1.7;
    }

    .grammar-blank {
        min-width: 50px !important;
        max-width: 140px !important;
        min-height: 18px !important;
        font-size: 13px !important;
        padding: 2px 3px 1px 3px !important;
        margin: 0 2px !important;
    }
}

/* 横屏模式优化 */
@media (max-height: 600px) and (orientation: landscape) {
    .grammar-quote-line {
        height: 24px;
        margin: -12px 0 10px 0;
    }

    .grammar-quote {
        padding: 0 12px;
        gap: 3px;
    }

    .grammar-quote .quote-mark {
        font-size: 14px;
    }

    .grammar-quote .quote-text {
        font-size: 11px;
        white-space: normal;
    }

    .grammar-content {
        padding: 10px 0;
    }

    .grammar-paragraph {
        margin-bottom: 12px;
        line-height: 1.6;
    }
}

/* 打印样式 */
@media print {
    .grammar-blank {
        border-bottom: 1px solid #000;
        background: transparent;
        color: #000;
    }
}

/* ========== 翻译气泡框样式 ========== */
.translation-tooltip {
    position: fixed;
    z-index: 9999;
    width: auto;
    min-width: 200px;
    max-width: 460px;
    height: auto;
    background: linear-gradient(135deg, #ffffff, #f8f9fa);
    border: 1px solid rgba(122, 168, 214, 0.3);
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(74, 111, 165, 0.2), 0 2px 8px rgba(74, 111, 165, 0.1);
    padding: 24px 12px 12px 12px;
    font-family: 'Nunito', sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: #4a6fa5;
    display: none;
    pointer-events: auto;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    animation: tooltipFadeIn 0.2s ease-out;
    user-select: none;
}

/* 拖拽条 */
.tooltip-drag-handle {
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 4px;
    background: rgba(122, 168, 214, 0.4);
    border-radius: 2px;
    transition: background 0.2s ease;
}

/* 使用伪元素创建透明的可点击区域，保持视觉样式不变 */
.tooltip-drag-handle::before {
    content: '';
    position: absolute;
    top: -12px;
    left: -20px;
    right: -20px;
    bottom: -12px;
    width: 80px;
    height: 28px;
}

.tooltip-drag-handle:hover {
    background: rgba(122, 168, 214, 0.6);
}

.tooltip-drag-handle:active {
    background: rgba(122, 168, 214, 0.8);
}

.tooltip-dragging,
.tooltip-dragging * {
    transition: none !important;
    animation: none !important;
}

/* 已拖动的气泡框禁用淡入动画 */
.translation-tooltip.tooltip-dragged {
    animation: none !important;
}

/* 拖拽时启用 GPU 加速 */
.translation-tooltip {
    will-change: auto;
    transform: translateZ(0);
}

.tooltip-dragging {
    will-change: transform !important;
}

/* 内容容器 */
.tooltip-content-container {
    width: 100%;
}

/* 气泡框内容 */
.tooltip-content {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* 原文区域 */
.tooltip-original-section {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(122, 168, 214, 0.2);
}

.tooltip-original-section .tooltip-para {
    font-size: 13px;
    color: #7aa8d6;
    font-weight: 500;
    font-style: italic;
    line-height: 1.5;
}

/* 译文区域 */
.tooltip-translation-section {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.tooltip-translation-section .tooltip-para {
    font-size: 15px;
    color: #4a6fa5;
    font-weight: 600;
    line-height: 1.5;
}

/* 加载状态 */
.tooltip-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 60px;
    color: #7aa8d6;
    font-size: 14px;
    gap: 8px;
}

.tooltip-loading::before {
    content: '';
    width: 16px;
    height: 16px;
    border: 2px solid rgba(122, 168, 214, 0.3);
    border-top-color: #7aa8d6;
    border-radius: 50%;
    animation: tooltipSpin 0.8s linear infinite;
}

/* 错误状态 */
.tooltip-error {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 60px;
    color: #dc3545;
    font-size: 14px;
}

/* 气泡框动画 */
@keyframes tooltipFadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes tooltipSpin {
    to {
        transform: rotate(360deg);
    }
}

/* 响应式适配 */
@media (max-width: 768px) {
    .translation-tooltip {
        min-width: 180px;
        max-width: 400px;
        padding: 22px 10px 10px 10px;
        font-size: 13px;
    }

    .tooltip-drag-handle {
        width: 36px;
        height: 3px;
        top: 5px;
    }

    .tooltip-content {
        gap: 10px;
    }

    .tooltip-original-section,
    .tooltip-translation-section {
        gap: 3px;
    }

    .tooltip-original-section {
        padding-bottom: 8px;
    }

    .tooltip-original {
        font-size: 12px;
    }

    .tooltip-translation {
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .translation-tooltip {
        min-width: 160px;
        max-width: 340px;
        padding: 20px 8px 8px 8px;
        font-size: 12px;
    }

    .tooltip-drag-handle {
        width: 32px;
        height: 3px;
        top: 4px;
    }

    .tooltip-content {
        gap: 8px;
    }

    .tooltip-original-section,
    .tooltip-translation-section {
        gap: 2px;
    }

    .tooltip-original-section {
        padding-bottom: 6px;
    }

    .tooltip-original {
        font-size: 11px;
    }

    .tooltip-translation {
        font-size: 13px;
    }
}