/**
 * ============================================
 * 题库与AI工具页面优化样式 - 国风设计
 * 基于04_exercises_题库 AI 工具页面优化.txt要求
 * ============================================
 */

/* ===== 页面全局背景：动态山水视频底纹 ===== */
.page-bg-video {
    position: fixed;
    inset: 0;
    z-index: -1;
    overflow: hidden;
}

.page-bg-video::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        to bottom,
        rgba(250, 248, 245, 0.3) 0%,
        rgba(250, 248, 245, 0.1) 50%,
        rgba(250, 248, 245, 0.4) 100%
    );
    pointer-events: none;
}

.page-bg-video-media {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    opacity: 0.15; /* 控制在 15% 左右，保证内容清晰可读 */
    pointer-events: none;
    filter: sepia(10%) saturate(80%); /* 添加轻微复古色调 */
}

/* ===== 页面标题区 ===== */
.page-header {
    padding: 3rem 0 2rem;
    text-align: center;
}

.page-header h1 {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: #5D3A1A;
    margin-bottom: 0.75rem;
}

.page-header p {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 1.1rem;
    color: #888;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== 双分区布局 ===== */
.section-divider {
    width: 1px;
    background: #8B4513;
    height: auto;
    min-height: 400px;
}

@media (max-width: 991.98px) {
    .section-divider {
        width: 100%;
        height: 1px;
        min-height: auto;
        margin: 2rem 0;
    }
}

/* ===== 题库模块 ===== */
.exercise-module {
    padding-right: 2rem;
    flex: none;
}

@media (max-width: 991.98px) {
    .exercise-module {
        padding-right: 0;
    }
}

/* 筛选导航区 */
.filter-nav-section {
    background: #E8E5E1;
    padding: 1.5rem 0;
    margin-bottom: 2rem;
    border-bottom: 1px solid #8B4513;
    border-top: 1px solid rgba(139, 69, 19, 0.1);
    border-radius: 8px;
}

.filter-btn-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
}

.filter-btn {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 15px;
    padding: 10px 24px;
    background: #FFFAF0;
    border: 1px solid #8B4513;
    border-radius: 8px;
    color: #5D3A1A;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.filter-btn:hover {
    background: #8B4513;
    color: #FFFAF0;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(139, 69, 19, 0.2);
}

.filter-btn.active {
    background: #DC143C;
    border-color: #DC143C;
    color: #FFFAF0;
}

/* 题库卡片 - 4:3比例 */
.exercise-card {
    aspect-ratio: 4/3;
    background: #FFFAF0;
    border: 1px solid #8B4513;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    opacity: 0;
    transform: translateY(20px);
}

.exercise-card.visible {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.exercise-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.exercise-card h3 {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 1.1rem;
    font-weight: 600;
    color: #363636;
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

.exercise-card .keyword {
    color: #8B4513;
    font-weight: 700;
}

/* 难度星级 - 朱砂红 */
.difficulty-stars {
    color: #DC143C;
    font-size: 1rem;
    margin-bottom: 0.5rem;
    letter-spacing: 2px;
}

/* 文本类型标签 - 赭石棕 */
.text-type-tag {
    display: inline-block;
    background: rgba(139, 69, 19, 0.1);
    color: #8B4513;
    font-size: 0.85rem;
    padding: 4px 12px;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.text-type-tag i {
    margin-right: 4px;
}

.exercise-content {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

/* 选项样式 */
.exercise-options {
    margin-bottom: 1rem;
}

.exercise-options .form-check {
    margin-bottom: 0.5rem;
}

.exercise-options .form-check-input:checked {
    background-color: #8B4513;
    border-color: #8B4513;
}

.exercise-options .form-check-label {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    color: #363636;
}

/* 国风按钮 */
.guofeng-btn {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    background: #8B4513;
    color: #FFFAF0;
    border: none;
    border-radius: 8px;
    padding: 10px 24px;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: auto;
}

.guofeng-btn:hover {
    background: #6B3410;
    transform: scale(1.02);
    box-shadow: 0 4px 12px rgba(139, 69, 19, 0.3);
}

/* 答案卡片 */
.answer-card {
    background: #FAF8F5;
    border-left: 3px solid #DC143C;
    padding: 1rem;
    border-radius: 0 8px 8px 0;
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
}

.answer-card .correct-answer {
    color: #8B4513;
}

.answer-card strong {
    color: #DC143C;
}

/* 文本域样式 */
.exercise-card textarea.form-control {
    background: #FAF8F5;
    border: 1px solid #D4C4B0;
    border-radius: 8px;
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    resize: vertical;
}

.exercise-card textarea.form-control:focus {
    border-color: #8B4513;
    box-shadow: 0 0 0 0.2rem rgba(139, 69, 19, 0.15);
}

/* ===== AI工具模块 ===== */
.ai-tool-module {
    padding-left: 1rem;
    position: sticky;
    top: 100px;
    align-self: flex-start;
    flex: none;
}

@media (max-width: 991.98px) {
    .ai-tool-module {
        padding-left: 0;
    }
}

/* AI工具卡片 - 书卷造型 */
.ai-tool-card {
    background: #FFFAF0;
    border: 1px solid #8B4513;
    border-radius: 8px;
    padding: 2rem;
    position: relative;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

/* 竹简纹装饰 */
.ai-tool-card::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    height: 4px;
    background: repeating-linear-gradient(
        90deg,
        rgba(139, 69, 19, 0.15) 0px,
        rgba(139, 69, 19, 0.15) 8px,
        transparent 8px,
        transparent 12px
    );
    border-radius: 2px;
}

.ai-tool-card::after {
    content: '';
    position: absolute;
    bottom: 10px;
    left: 10px;
    right: 10px;
    height: 4px;
    background: repeating-linear-gradient(
        90deg,
        rgba(139, 69, 19, 0.15) 0px,
        rgba(139, 69, 19, 0.15) 8px,
        transparent 8px,
        transparent 12px
    );
    border-radius: 2px;
}

.ai-tool-card .tool-icon {
    font-size: 3rem;
    color: #8B4513;
    display: block;
    text-align: center;
    margin-bottom: 1rem;
}

.ai-tool-card h3 {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: #5D3A1A;
    text-align: center;
    margin-bottom: 0.75rem;
}

.ai-tool-card > p {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    color: #666;
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

/* AI输入框 - 书卷造型 */
.ai-input {
    flex: 1;
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    background: #FAF8F5;
    border: 1px solid #8B4513;
    border-right: none;
    border-radius: 8px 0 0 8px;
    padding: 12px 16px;
    font-size: 0.95rem;
    color: #363636;
    caret-color: #DC143C; /* 朱砂红光标 */
}

.ai-input::placeholder {
    color: #999;
    font-style: italic;
}

.ai-input:focus {
    outline: none;
    background: #FFF;
    box-shadow: inset 0 0 0 1px rgba(139, 69, 19, 0.2);
}

/* AI发送按钮 */
.ai-btn {
    background: #8B4513;
    color: #FFFAF0;
    border: 1px solid #8B4513;
    border-radius: 0 8px 8px 0;
    padding: 12px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.ai-btn:hover {
    background: #6B3410;
    transform: scale(1.05);
}

.ai-btn i {
    font-size: 1.2rem;
}

/* AI回答区域 */
.ai-response-box {
    background: #FAF8F5;
    border: 1px solid #D4C4B0;
    border-radius: 8px;
    padding: 1rem;
    min-height: 120px;
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    position: relative;
}

.ai-label {
    display: block;
    color: #8B4513;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.ai-label i {
    margin-right: 6px;
}

/* 加载动画 */
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(139, 69, 19, 0.2);
    border-top-color: #8B4513;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

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

/* ===== 回到顶部按钮 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: #8B4513;
    color: #FFFAF0;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: #6B3410;
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.back-to-top i {
    font-size: 1.5rem;
}

/* ===== 延迟动画类 ===== */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }

/* ===== 响应式适配 ===== */
@media (max-width: 768px) {
    .page-header h1 {
        font-size: 1.8rem;
    }
    
    .page-header p {
        font-size: 1rem;
    }
    
    .filter-btn {
        font-size: 14px;
        padding: 8px 16px;
    }
    
    .exercise-card {
        aspect-ratio: auto;
        min-height: 300px;
    }
    
    .ai-tool-card {
        padding: 1.5rem;
    }
    
    .ai-input {
        font-size: 16px; /* 防止iOS缩放 */
    }
}

/* ===== 数字点阵装饰（AI工具区轻量装饰） ===== */
.digital-pattern {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 60px;
    height: 60px;
    background-image: radial-gradient(circle, rgba(139, 69, 19, 0.1) 1px, transparent 1px);
    background-size: 8px 8px;
    pointer-events: none;
    opacity: 0.5;
}

/* ===== 互动小游戏模块 - 科技+古典新中式风格 ===== */
.interactive-game-card {
    background: linear-gradient(135deg, #FFFAF0 0%, #FAF8F5 100%);
    border: 1px solid #8B4513;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
    overflow: hidden;
}

.interactive-game-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.interactive-game-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, transparent, #8B4513, transparent);
    border-radius: 8px 8px 0 0;
}

/* 游戏头部 */
.game-header {
    margin-bottom: 1.5rem;
}

.game-title {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 1.3rem;
    font-weight: 700;
    color: #5D3A1A;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
}

.game-title i {
    color: #8B4513;
    font-size: 1.2rem;
}

.game-description {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    font-size: 0.95rem;
    color: #A0826D;
    margin: 0;
    line-height: 1.6;
}

/* 游戏内容区 */
.game-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    padding: 1rem;
    background: rgba(139, 69, 19, 0.03);
    border-radius: 8px;
}

/* 游戏图标容器 */
.game-icon-wrapper {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #8B4513 0%, #A0522D 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(139, 69, 19, 0.3);
    transition: transform 0.3s ease;
}

.game-icon-wrapper:hover {
    transform: scale(1.1);
}

.game-icon {
    font-size: 2.5rem;
    color: #FFFAF0;
}

/* 游戏按钮 - 统一页面交互按钮样式 */
.game-btn {
    font-family: 'Noto Serif SC', 'Source Han Serif SC', '思源宋体', serif;
    background: linear-gradient(135deg, #8B4513 0%, #A0522D 100%);
    color: #FFFAF0;
    border: none;
    border-radius: 8px;
    padding: 12px 32px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(139, 69, 19, 0.2);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-width: 160px;
    justify-content: center;
}

.game-btn:hover {
    background: linear-gradient(135deg, #A0522D 0%, #CD853F 100%);
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 6px 16px rgba(139, 69, 19, 0.3);
}

.game-btn:active {
    transform: translateY(0) scale(0.98);
    box-shadow: 0 2px 8px rgba(139, 69, 19, 0.2);
}

.game-btn i {
    font-size: 1.1rem;
}

/* ===== 互动小游戏模块响应式适配 ===== */
@media (max-width: 768px) {
    .interactive-game-card {
        padding: 1.25rem;
    }
    
    .game-title {
        font-size: 1.1rem;
    }
    
    .game-description {
        font-size: 0.9rem;
    }
    
    .game-content {
        padding: 0.75rem;
    }
    
    .game-icon-wrapper {
        width: 70px;
        height: 70px;
    }
    
    .game-icon {
        font-size: 2rem;
    }
    
    .game-btn {
        padding: 10px 24px;
        font-size: 0.95rem;
        min-width: 140px;
    }
}

@media (max-width: 576px) {
    .game-title {
        font-size: 1rem;
    }
    
    .game-content {
        gap: 1rem;
    }
    
    .game-icon-wrapper {
        width: 60px;
        height: 60px;
    }
    
    .game-icon {
        font-size: 1.8rem;
    }
    
    .game-btn {
        width: 100%;
        padding: 12px 20px;
        font-size: 0.95rem;
    }
}