/* 按钮组件 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
    justify-content: center;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a6fd8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-warning {
    background: #ffc107;
    color: #212529;
}

.btn-warning:hover {
    background: #e0a800;
}

.btn-outline {
    background: transparent;
    border: 2px solid #667eea;
    color: #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* 表单组件 */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #dee2e6;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.input-group {
    position: relative;
    display: flex;
    align-items: center;
}

.input-group i {
    position: absolute;
    left: 1rem;
    color: #666;
    z-index: 1;
}

.input-group input {
    padding-left: 3rem;
}

.code-input-group {
    display: flex;
    gap: 0.5rem;
}

.code-input-group input {
    flex: 1;
}

.code-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 0.75rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.3s;
}

.code-btn:hover {
    background: #5a6fd8;
}

.code-btn:disabled {
    background: #6c757d;
    cursor: not-allowed;
}

.code-timer {
    margin-top: 0.5rem;
    font-size: 0.875rem;
    color: #666;
}

/* 卡片组件 */
.card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid #dee2e6;
    background: #f8f9fa;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid #dee2e6;
    background: #f8f9fa;
}

/* 徽章组件 */
.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    border-radius: 3px;
    color: white;
}

.badge-primary {
    background: #667eea;
}

.badge-secondary {
    background: #6c757d;
}

.badge-success {
    background: #28a745;
}

.badge-danger {
    background: #dc3545;
}

.badge-warning {
    background: #ffc107;
    color: #212529;
}

.badge-info {
    background: #17a2b8;
}

/* 警告框组件 */
.alert {
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    border: 1px solid transparent;
}

.alert-success {
    background: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
}

.alert-danger {
    background: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
}

.alert-warning {
    background: #fff3cd;
    border-color: #ffeaa7;
    color: #856404;
}

.alert-info {
    background: #d1ecf1;
    border-color: #bee5eb;
    color: #0c5460;
}

/* 加载组件 */
.loading {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid #f3f3f3;
    border-top: 2px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 进度条组件 */
.progress {
    width: 100%;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: #667eea;
    transition: width 0.3s;
}

.progress-text {
    font-size: 0.875rem;
    color: #666;
    margin-top: 0.5rem;
}

/* 标签组件 */
.tag {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 15px;
    font-size: 0.875rem;
    color: #666;
    margin: 0.25rem;
}

.tag-primary {
    background: #e3f2fd;
    border-color: #bbdefb;
    color: #1976d2;
}

.tag-success {
    background: #e8f5e8;
    border-color: #c8e6c9;
    color: #388e3c;
}

.tag-warning {
    background: #fff8e1;
    border-color: #ffecb3;
    color: #f57c00;
}

.tag-danger {
    background: #ffebee;
    border-color: #ffcdd2;
    color: #d32f2f;
}

/* 工具提示组件 */
.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 120px;
    background-color: #333;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -60px;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.875rem;
}

.tooltip .tooltiptext::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: #333 transparent transparent transparent;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

/* 下拉菜单组件 */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: white;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    border-radius: 5px;
    overflow: hidden;
}

.dropdown-content a {
    color: #333;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    transition: background-color 0.3s;
}

.dropdown-content a:hover {
    background-color: #f8f9fa;
}

.dropdown:hover .dropdown-content {
    display: block;
}

/* 文件上传组件 */
.file-upload {
    position: relative;
    display: inline-block;
    cursor: pointer;
    width: 100%;
}

.file-upload input[type="file"] {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.file-upload-display {
    border: 2px dashed #dee2e6;
    border-radius: 5px;
    padding: 2rem;
    text-align: center;
    transition: border-color 0.3s, background-color 0.3s;
    background: #f8f9fa;
}

.file-upload-display:hover {
    border-color: #667eea;
    background: #f0f2ff;
}

.file-upload-display i {
    font-size: 2rem;
    color: #667eea;
    margin-bottom: 0.5rem;
    display: block;
}

.file-upload-display span {
    color: #666;
    font-size: 1rem;
}

/* 评分组件 */
.rating {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.rating input[type="radio"] {
    display: none;
}

.rating label {
    cursor: pointer;
    font-size: 1.5rem;
    color: #ddd;
    transition: color 0.3s;
}

.rating label:hover,
.rating label:hover ~ label {
    color: #ffc107;
}

.rating input[type="radio"]:checked ~ label {
    color: #ffc107;
}

.rating-display {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.rating-text {
    font-size: 0.875rem;
    color: #666;
}

/* 空状态组件 */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: #666;
}

.empty-state i {
    font-size: 4rem;
    color: #ddd;
    margin-bottom: 1rem;
}

.empty-state h3 {
    margin-bottom: 0.5rem;
    color: #333;
}

.empty-state p {
    margin-bottom: 1.5rem;
}

/* 骨架屏组件 */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.skeleton-text {
    height: 1rem;
    border-radius: 4px;
    margin-bottom: 0.5rem;
}

.skeleton-title {
    height: 1.5rem;
    width: 60%;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.skeleton-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
}

.skeleton-card {
    background: white;
    border-radius: 10px;
    padding: 1rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* 响应式工具类 */
.d-none {
    display: none !important;
}

.d-block {
    display: block !important;
}

.d-flex {
    display: flex !important;
}

.d-grid {
    display: grid !important;
}

.text-center {
    text-align: center !important;
}

.text-left {
    text-align: left !important;
}

.text-right {
    text-align: right !important;
}

.mt-1 { margin-top: 0.25rem !important; }
.mt-2 { margin-top: 0.5rem !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.mt-5 { margin-top: 3rem !important; }

.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mb-4 { margin-bottom: 1.5rem !important; }
.mb-5 { margin-bottom: 3rem !important; }

.p-1 { padding: 0.25rem !important; }
.p-2 { padding: 0.5rem !important; }
.p-3 { padding: 1rem !important; }
.p-4 { padding: 1.5rem !important; }
.p-5 { padding: 3rem !important; }

/* 动画类 */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.slide-up {
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.bounce {
    animation: bounce 0.6s ease-in-out;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}