/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Helvetica Neue', Arial, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --text-color: #333;
    --border-radius: clamp(0.5rem, 1vw, 0.8rem);
    --box-shadow: 0 clamp(0.25rem, 0.5vw, 0.375rem) clamp(0.375rem, 0.75vw, 0.5rem) rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    
    /* 动态字体大小 */
    font-size: clamp(0.875rem, 2vw, 1rem);
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 头部样式 */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: clamp(0.5rem, 2vw, 0.9375rem);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 10;
}

.back-btn {
    color: white;
    font-size: clamp(1.2rem, 3vw, 1.75rem);
    background: none;
    border: clamp(0.15rem, 0.3vw, 0.2rem) solid #ffffff;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: clamp(0.25rem, 0.75vw, 0.3125rem);
    padding: clamp(0.3rem, 0.75vw, 0.3125rem);
    border-radius: 10%;
    transition: background-color 0.2s;
}

.back-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.header-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 500;
    text-align: center;
    flex: 1;
    padding-right: clamp(2.5rem, 6vw, 3rem);
}

/* 容器样式 */
.container {
    width: 100%;
    max-width: clamp(20rem, 100vw, 50rem);
    margin: clamp(0.5rem, 2vw, 1rem) auto;
    padding: 0 clamp(1rem, 4vw, 1.25rem);
}

/* 入驻表单容器 */
.join-container {
    flex: 1;
    padding-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.join-card {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    margin: 0 auto;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(clamp(1rem, 3vw, 1.875rem));
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 卡片头部 */
.card-header {
    background: linear-gradient(135deg, var(--primary-color), #2980b9);
    color: white;
    padding: clamp(1.25rem, 4vw, 1.5625rem);
    text-align: center;
}

.card-header h2 {
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    margin-bottom: clamp(0.4rem, 1vw, 0.5rem);
}

.card-header p {
    opacity: 0.9;
    font-size: clamp(0.8rem, 2vw, 0.9rem);
}

/* 表单样式 */
.join-form {
    padding: clamp(1rem, 3vw, 1.875rem);
}

.form-group {
    margin-bottom: clamp(1rem, 2vw, 1.25rem);
}

.form-group label {
    display: block;
    margin-bottom: clamp(0.3rem, 1vw, 0.375rem);
    font-weight: 600;
    color: var(--secondary-color);
    font-size: clamp(0.9rem, 2vw, 1rem);
}

.form-group label.required::after {
    content: " *";
    color: var(--accent-color);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: clamp(0.6rem, 1.5vw, 0.875rem) clamp(0.8rem, 2vw, 1rem);
    border: clamp(0.1rem, 0.2vw, 0.125rem) solid #e1e5e9;
    border-radius: var(--border-radius);
    font-size: clamp(0.85rem, 2vw, 0.95rem);
    transition: var(--transition);
    background-color: white;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 clamp(0.2rem, 0.5vw, 0.3rem) rgba(52, 152, 219, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: clamp(5rem, 15vw, 6.25rem);
}

.form-group .hint {
    font-size: clamp(0.7rem, 1.5vw, 0.8rem);
    color: #666;
    margin-top: clamp(0.2rem, 0.5vw, 0.25rem);
}

/* 分类选择器 */
.category-selector {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(clamp(7rem, 15vw, 8.75rem), 1fr));
    gap: clamp(0.5rem, 1.5vw, 0.625rem);
    margin-top: clamp(0.4rem, 1vw, 0.5rem);
}

/* 文件上传 */
.file-upload {
    border: clamp(0.1rem, 0.2vw, 0.125rem) dashed #ddd;
    border-radius: var(--border-radius);
    padding: clamp(1.25rem, 3vw, 1.5625rem);
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.file-upload:hover {
    border-color: var(--primary-color);
    background-color: rgba(52, 152, 219, 0.05);
}

.file-upload p {
    color: #666;
    margin-bottom: clamp(0.2rem, 0.5vw, 0.25rem);
    font-size: clamp(0.8rem, 2vw, 0.9rem);
}

.file-upload small {
    color: #999;
    font-size: clamp(0.7rem, 1.5vw, 0.8rem);
}

.file-upload input[type="file"] {
    display: none;
}

.file-list {
    margin-top: clamp(0.4rem, 1vw, 0.5rem);
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: clamp(0.3rem, 1vw, 0.375rem) clamp(0.6rem, 1.5vw, 0.875rem);
    background-color: var(--light-color);
    border-radius: var(--border-radius);
    margin-bottom: clamp(0.2rem, 0.5vw, 0.25rem);
    font-size: clamp(0.75rem, 1.5vw, 0.85rem);
}

.file-item span {
    flex: 1;
    margin-right: clamp(0.4rem, 1vw, 0.5rem);
}

.remove-file {
    color: var(--accent-color);
    background: none;
    border: none;
    cursor: pointer;
    font-size: clamp(0.9rem, 2vw, 1.1rem);
}

/* 协议条款 */
.agreement-box {
    background-color: var(--light-color);
    border-radius: var(--border-radius);
    padding: clamp(0.8rem, 2vw, 1rem);
    margin: clamp(1rem, 2.5vw, 1.25rem) 0;
    max-height: clamp(9rem, 25vw, 11.25rem);
    overflow-y: auto;
    font-size: clamp(0.75rem, 1.5vw, 0.85rem);
}

.agreement-box h3 {
    margin-bottom: clamp(0.5rem, 1.5vw, 0.625rem);
    color: var(--secondary-color);
    font-size: clamp(0.9rem, 2vw, 1rem);
}

.agreement-box p {
    margin-bottom: clamp(0.4rem, 1vw, 0.5rem);
    color: #666;
}

.checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: clamp(0.4rem, 1vw, 0.5rem);
    margin-bottom: clamp(0.8rem, 2vw, 1rem);
}

.checkbox-group input[type="checkbox"] {
    width: clamp(1rem, 2.5vw, 1.125rem);
    height: clamp(1rem, 2.5vw, 1.125rem);
    margin-top: clamp(0.1rem, 0.3vw, 0.125rem);
}

.checkbox-group label {
    flex: 1;
    font-weight: normal;
    font-size: clamp(0.8rem, 2vw, 0.9rem);
}

.terms-link {
    color: var(--primary-color);
    text-decoration: none;
}

.terms-link:hover {
    text-decoration: underline;
}

/* 表单操作按钮 */
.form-actions {
    display: flex;
    gap: clamp(0.6rem, 1.5vw, 0.75rem);
    margin-top: clamp(1.5rem, 3vw, 1.875rem);
}

.submit-btn {
    flex: 1;
    background: linear-gradient(135deg, var(--primary-color), #2980b9);
    color: white;
    border: none;
    padding: clamp(0.8rem, 2vw, 1rem);
    border-radius: var(--border-radius);
    font-size: clamp(0.9rem, 2vw, 1rem);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(0.4rem, 1vw, 0.5rem);
}

.submit-btn:hover {
    transform: translateY(clamp(-0.1rem, -0.3vw, -0.125rem));
    box-shadow: 0 clamp(0.4rem, 1vw, 0.5rem) clamp(0.6rem, 1.5vw, 0.75rem) rgba(52, 152, 219, 0.2);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.card-footer {
    color: #000000;
    padding: clamp(1.25rem, 4vw, 1.5625rem);
    text-align: center;
}
.card-footer img{
    width:80%;
}

/* 加载动画 */
.spinner {
    display: inline-block;
    width: clamp(1rem, 2.5vw, 1.125rem);
    height: clamp(1rem, 2.5vw, 1.125rem);
    border: clamp(0.15rem, 0.4vw, 0.2rem) solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

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

/* 响应式设计 */
@media (max-width: clamp(30rem, 90vw, 48rem)) {
    .container {
        padding: 0 clamp(0.8rem, 3vw, 1rem);
    }
    
    .card-header {
        padding: clamp(1rem, 3vw, 1.25rem);
    }
    
    .card-header h2 {
        font-size: clamp(1rem, 2.5vw, 1.3rem);
    }
    
    .join-form {
        padding: clamp(0.8rem, 2.5vw, 1rem);
    }
    
    .category-selector {
        grid-template-columns: repeat(auto-fill, minmax(clamp(6rem, 12vw, 7.5rem), 1fr));
    }
    
    .form-actions {
        flex-direction: column;
    }
}

@media (max-width: clamp(20rem, 60vw, 30rem)) {
    .card-header {
        padding: clamp(0.8rem, 2vw, 1rem);
    }
    
    .card-header h2 {
        font-size: clamp(0.9rem, 2vw, 1.1rem);
    }
    
    .card-header p {
        font-size: clamp(0.7rem, 1.5vw, 0.8rem);
    }
    
    .join-form {
        padding: clamp(0.6rem, 2vw, 0.8rem);
    }
    
    .form-group input,
    .form-group select,
    .form-group textarea {
        padding: clamp(0.5rem, 1.2vw, 0.6rem) clamp(0.6rem, 1.5vw, 0.8rem);
    }
    
    .category-selector {
        grid-template-columns: repeat(2, 1fr);
    }
}