/* 原子知识空间样式表 - 现代化设计 */

:root {
    /* 现代化配色方案 */
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --primary-light: #4895ef;
    --secondary-color: #7209b7;
    --accent-color: #f72585;
    --success-color: #4cc9f0;
    --warning-color: #f8961e;
    
    /* 渐变背景 */
    --gradient-primary: linear-gradient(135deg, #4361ee 0%, #3a0ca3 100%);
    --gradient-secondary: linear-gradient(135deg, #7209b7 0%, #560bad 100%);
    --gradient-accent: linear-gradient(135deg, #f72585 0%, #b5179e 100%);
    
    /* 现代化背景 */
    --background-color: #f8f9ff;
    --background-gradient: linear-gradient(135deg, #f8f9ff 0%, #eef2ff 100%);
    --card-background: rgba(255, 255, 255, 0.95);
    --card-background-hover: rgba(255, 255, 255, 1);
    --glass-background: rgba(255, 255, 255, 0.25);
    --glass-border: rgba(255, 255, 255, 0.18);
    
    /* 文字颜色 */
    --text-color: #1e293b;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    
    /* 边框和阴影 */
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow: 0 4px 20px rgba(67, 97, 238, 0.08);
    --shadow-hover: 0 8px 40px rgba(67, 97, 238, 0.15);
    --shadow-card: 0 10px 25px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* 间距 */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    
    /* 动画 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--background-gradient);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* 现代化导航栏样式 */
.navbar {
    background: var(--gradient-primary) !important;
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 20px rgba(67, 97, 238, 0.15);
    padding: 1rem 0;
    border-bottom: none;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.75rem;
    background: linear-gradient(45deg, #fff, #f0f4ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: var(--transition-normal);
}

.navbar-brand:hover {
    transform: translateY(-1px);
}

.navbar-brand i {
    background: linear-gradient(45deg, #fff, #f0f4ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1.8rem;
}

.navbar-text {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* 现代化搜索区域样式 */
.container.mt-4 {
    margin-top: 2rem !important;
}

.input-group {
    box-shadow: var(--shadow-card);
    border-radius: var(--radius-lg);
    background: var(--card-background);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    transition: var(--transition-normal);
}

.input-group:focus-within {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

/* 搜索框动画状态 */
.input-group.focused {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(67, 97, 238, 0.15);
}

.input-group.searching {
    border-color: var(--primary-color);
}

.input-group.searching .form-control {
    color: var(--primary-color);
}

.form-control {
    border: none;
    background: transparent;
    padding: 1rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-color);
}

.form-control:focus {
    border: none;
    box-shadow: none;
    background: transparent;
}

.form-control::placeholder {
    color: var(--text-light);
    font-weight: 400;
}

.btn-outline-primary {
    border: none;
    background: var(--gradient-primary);
    color: white;
    padding: 1rem 1.5rem;
    font-weight: 600;
    transition: var(--transition-normal);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

.btn-outline-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(67, 97, 238, 0.3);
}

/* 现代化筛选区域 */
.col-md-4 {
    margin-top: 1.5rem;
}

.d-flex.gap-2 {
    gap: 1rem !important;
}

.form-select {
    border: none;
    background: var(--card-background);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    padding: 1rem 1.5rem;
    font-weight: 500;
    color: var(--text-color);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--glass-border);
    transition: var(--transition-normal);
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* 现代化知识卡片样式 */
.knowledge-card {
    background: var(--card-background);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-card);
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    height: 100%;
    overflow: hidden;
    position: relative;
    animation: cardSlideIn 0.6s ease forwards;
    opacity: 0;
    transform: translateY(30px);
}

.knowledge-card.animated {
    animation: none;
    opacity: 1;
    transform: translateY(0);
}

/* 确保悬停效果的优先级高于animated类 */
.knowledge-card.animated:hover {
    transform: translateY(-8px) scale(1.05) !important;
    box-shadow: var(--shadow-hover) !important;
    background: var(--card-background-hover) !important;
    z-index: 10 !important;
}

@keyframes cardSlideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.knowledge-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.knowledge-card:hover {
    transform: translateY(-8px) scale(1.05);
    box-shadow: var(--shadow-hover);
    background: var(--card-background-hover);
    z-index: 10;
}

.knowledge-card:hover::before {
    transform: scaleX(1);
}

/* 缩略图悬停放大效果 */
.knowledge-card:hover .thumbnail {
    transform: scale(1.1);
}

.knowledge-card.animated:hover .thumbnail {
    transform: scale(1.1) !important;
}

.knowledge-card:hover .thumbnail i {
    transform: scale(1.2) rotate(5deg);
}

.knowledge-card.animated:hover .thumbnail i {
    transform: scale(1.2) rotate(5deg) !important;
}

/* 卡片内容悬停效果 */
.knowledge-card:hover .card-title {
    background: linear-gradient(45deg, var(--primary-color), #2980b9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .card-title {
    background: linear-gradient(45deg, var(--primary-color), #2980b9) !important;
    -webkit-background-clip: text !important;
    -webkit-text-fill-color: transparent !important;
    background-clip: text !important;
}

.knowledge-card:hover .card-text {
    opacity: 1;
    color: var(--text-color);
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .card-text {
    opacity: 1 !important;
    color: var(--text-color) !important;
}

/* 分类标签悬停效果 */
.knowledge-card:hover .category-badge {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .category-badge {
    transform: translateY(-2px) !important;
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3) !important;
}

/* 标签悬停效果 */
.knowledge-card:hover .tag {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-1px);
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .tag {
    background-color: var(--primary-color) !important;
    color: white !important;
    border-color: var(--primary-color) !important;
    transform: translateY(-1px) !important;
}

/* 统计信息悬停效果 */
.knowledge-card:hover .stats {
    border-top-color: var(--primary-color);
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .stats {
    border-top-color: var(--primary-color) !important;
}

.knowledge-card:hover .stat-item {
    color: var(--primary-color);
    transition: all 0.3s ease;
}

.knowledge-card.animated:hover .stat-item {
    color: var(--primary-color) !important;
}



.knowledge-card .card-body {
    padding: 2rem;
    position: relative;
    z-index: 1;
}

.knowledge-card .card-title {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-color);
    line-height: 1.3;
    background: linear-gradient(45deg, var(--text-color), var(--text-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.knowledge-card .card-text {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
    opacity: 0.9;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 分类标签样式 */
.category-badge {
    background: linear-gradient(135deg, var(--primary-color), #2980b9);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    display: inline-block;
}

/* 标签样式 */
.tags-container {
    margin-bottom: 1rem;
}

.tag {
    background-color: var(--background-color);
    color: var(--text-muted);
    padding: 0.2rem 0.5rem;
    border-radius: 12px;
    font-size: 0.7rem;
    margin-right: 0.3rem;
    margin-bottom: 0.3rem;
    display: inline-block;
    border: 1px solid var(--border-color);
}

/* 统计信息样式 */
.stats {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 0.75rem;
    margin-top: auto;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.stat-item i {
    font-size: 0.7rem;
}

/* 缩略图样式 */
.knowledge-card .thumbnail {
    width: 100%;
    height: 120px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 8px 8px 0 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2.5rem;
    transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.knowledge-card .thumbnail i {
    transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.knowledge-card .thumbnail.化学 { background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%); }
.knowledge-card .thumbnail.数学 { background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%); }
.knowledge-card .thumbnail.物理 { background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%); }
.knowledge-card .thumbnail.编程 { background: linear-gradient(135deg, #fa709a 0%, #fee140 100%); }
.knowledge-card .thumbnail.语言 { background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%); }
.knowledge-card .thumbnail.其他 { background: linear-gradient(135deg, #d299c2 0%, #fef9d7 100%); }

/* 按钮样式 */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #2980b9);
    border: none;
    border-radius: 8px;
    padding: 0.5rem 1.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

/* 知识卡片内的预览按钮样式 */
.knowledge-card .btn-outline-primary {
    border: none;
    background: var(--gradient-primary);
    color: white;
    border-radius: 8px;
    padding: 0.5rem 1.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.knowledge-card .btn-outline-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
}

/* 加载动画 */
.spinner-border {
    width: 3rem;
    height: 3rem;
}

/* 空状态样式 */
#emptyState {
    padding: 4rem 2rem;
}

#emptyState i {
    opacity: 0.5;
}

/* 现代化响应式设计 */
@media (max-width: 768px) {
    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    
    .navbar-brand {
        font-size: 1.4rem;
    }
    
    .navbar-text {
        font-size: 0.9rem;
        padding: 0.4rem 0.8rem;
    }
    
    .container.mt-4 {
        margin-top: 1.5rem !important;
        padding: 0 1rem;
    }
    
    .input-group {
        margin-bottom: 1.5rem;
        border-radius: var(--radius-md);
    }
    
    .form-control {
        padding: 0.875rem 1.25rem;
        font-size: 0.95rem;
    }
    
    .btn-outline-primary {
        padding: 0.875rem 1.25rem;
    }
    
    .d-flex.gap-2 {
        flex-direction: column;
        gap: 1rem !important;
    }
    
    .form-select {
        padding: 0.875rem 1.25rem;
        font-size: 0.95rem;
    }
    
    .knowledge-card {
        margin-bottom: 1.5rem;
        border-radius: var(--radius-lg);
    }
    
    .knowledge-card:hover {
        transform: translateY(-4px) scale(1.01);
    }
    
    .knowledge-card .card-body {
        padding: 1.5rem;
    }
    
    .knowledge-card .card-title {
        font-size: 1.2rem;
    }
    
    .knowledge-card .card-text {
        font-size: 0.9rem;
    }
    
    .stats {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .col-md-4 {
        margin-top: 1rem;
    }
    
    .modal-dialog {
        margin: 1rem;
    }
    
    .modal-content {
        border-radius: var(--radius-lg);
    }
    
    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 1.5rem;
    }
    
    .modal-title {
        font-size: 1.3rem;
    }
}

@media (max-width: 576px) {
    .navbar-brand {
        font-size: 1.2rem;
    }
    
    .container.mt-4 {
        margin-top: 1rem !important;
        padding: 0 0.75rem;
    }
    
    .input-group {
        margin-bottom: 1rem;
    }
    
    .form-control {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
    
    .btn-outline-primary {
        padding: 0.75rem 1rem;
    }
    
    .knowledge-card .card-body {
        padding: 1.25rem;
    }
    
    .knowledge-card .card-title {
        font-size: 1.1rem;
    }
    
    .thumbnail {
        height: 100px;
        font-size: 2rem;
    }
    
    .modal-dialog {
        margin: 0.5rem;
    }
    
    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 1.25rem;
    }
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-color);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #2980b9;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.knowledge-card {
    animation: fadeIn 0.5s ease-out;
}

/* 搜索高亮 */
.highlight {
    background-color: #fff3cd;
    padding: 0.1rem 0.2rem;
    border-radius: 3px;
    font-weight: 600;
}

/* 现代化模态框样式 */
.modal-content {
    border-radius: var(--radius-xl);
    border: none;
    box-shadow: var(--shadow-hover);
    background: var(--card-background);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
}

.modal-header {
    border-bottom: 1px solid var(--glass-border);
    padding: 2rem 2rem 1rem;
    background: linear-gradient(135deg, rgba(67, 97, 238, 0.05), rgba(255, 107, 107, 0.05));
}

.modal-title {
    font-weight: 700;
    font-size: 1.5rem;
    background: linear-gradient(45deg, var(--text-color), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal-body {
    padding: 2rem;
    max-height: 70vh;
    overflow-y: auto;
    font-size: 1.05rem;
    line-height: 1.7;
}

.modal-footer {
    border-top: 1px solid var(--glass-border);
    padding: 1.5rem 2rem;
    background: rgba(255, 255, 255, 0.02);
}

/* 现代化加载状态 */
#loading {
    text-align: center;
    padding: 6rem 2rem;
}

.loading-animation {
    display: inline-block;
}

.loading-dots {
    display: flex;
    gap: 8px;
    justify-content: center;
    margin-bottom: 2rem;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--gradient-primary);
    animation: bounce 1.4s ease-in-out infinite both;
}

.dot-1 {
    animation-delay: -0.32s;
}

.dot-2 {
    animation-delay: -0.16s;
}

.dot-3 {
    animation-delay: 0s;
}

@keyframes bounce {
    0%, 80%, 100% {
        transform: scale(0);
        opacity: 0.5;
    }
    40% {
        transform: scale(1);
        opacity: 1;
    }
}

#loading h4 {
    margin-top: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
    font-size: 1.5rem;
    background: linear-gradient(45deg, var(--text-color), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

#loading p {
    color: var(--text-light);
    margin-top: 0.75rem;
    font-size: 1.1rem;
}

/* 工具提示样式 */
.tooltip {
    font-size: 0.8rem;
}

/* 选择框样式 */
.form-select {
    border-radius: 8px;
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
}

/* 网格布局优化 */
.row.g-4 {
    margin-left: -0.5rem;
    margin-right: -0.5rem;
}

.row.g-4 > [class*="col-"] {
    padding-left: 0.5rem;
    padding-right: 0.5rem;
}