/*
 * 设计理念:
 * 1. 现代 & 简洁: 采用现代设计语言，强调简洁、清晰和易用性。
 * 2. 色彩方案: 主色调采用专业且友好的蓝色 (#007BFF)，辅以中性灰色，营造出清爽、值得信赖的视觉感受。
 * 3. 字体: 引入 'Noto Sans SC'，提升中文和数字的显示效果，增强可读性。
 * 4. 交互反馈: 为所有可交互元素（按钮、输入框、链接）提供清晰的 hover 和 focus 状态，提升用户体验和可访问性。
 * 5. 响应式设计: 优化移动端体验，确保在不同尺寸的设备上都有一致且美观的展现。
 * 6. 细节质感: 通过柔和的阴影、平滑的过渡动画和合适的间距，提升界面的精致感。
 */

/* --- 变量定义 --- */
:root {
    --primary-color: #007BFF; /* 专业蓝 */
    --primary-color-dark: #0056b3;
    --secondary-color: #6c757d; /* 中性灰 */
    --background-color: #f4f7f9; /* 页面背景色 */
    --container-bg: #ffffff;
    --text-color: #333;
    --label-color: #495057;
    --border-color: #dee2e6;
    --input-bg: #f8f9fa;
    --success-color: #28a745;
    --error-color: #dc3545;
    --font-family: 'Noto Sans SC', sans-serif;
    --border-radius: 8px;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --transition-speed: 0.3s;
}

/* --- 全局样式 --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    padding: 20px;
    font-size: 16px; /* 调大基础字体 */
}

.container {
    max-width: 800px;
    margin: 20px auto;
    background: var(--container-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
}

/* --- 头部样式 --- */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 40px 30px;
    text-align: center;
}

header h1 {
    font-size: 2.2em;
    margin-bottom: 10px;
    font-weight: 500;
}

header p {
    font-size: 1.1em;
    opacity: 0.9;
}

/* --- 消息提示 --- */
.messages {
    padding: 20px 30px 0;
}

.alert {
    padding: 15px 20px;
    border-radius: var(--border-radius);
    margin-bottom: 15px;
    border: 1px solid transparent;
}

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

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

/* --- 表单样式 --- */
.registration-form {
    padding: 30px;
}

.form-section {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
}

.form-section:last-of-type {
    border-bottom: none;
}

.form-section h2 {
    color: var(--primary-color);
    font-size: 1.4em;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary-color);
    display: inline-block;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--label-color);
    font-size: 1.1em; /* 调大标签字体 */
}

.required {
    color: var(--error-color);
    margin-left: 4px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1.1em; /* 调大输入框字体 */
    font-family: var(--font-family);
    transition: border-color var(--transition-speed), box-shadow var(--transition-speed);
    background-color: var(--input-bg);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
    background-color: white;
}

.form-group input.error,
.form-group textarea.error {
    border-color: var(--error-color);
}

.form-group small {
    display: block;
    margin-top: 5px;
    color: var(--secondary-color);
    font-size: 0.9em;
}

/* --- 特定表单元素 --- */
.validity-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin-right: 5px;
}

.date-range {
    display: flex;
    align-items: center;
    gap: 10px;
}

.date-range input {
    cursor: pointer;
}

/* 长期有效复选框样式 */
.permanent-checkbox {
    width: 20px !important;
    height: 20px !important;
    margin-right: 10px;
    cursor: pointer;
}

.permanent-label {
    font-size: 1.2em !important;
    font-weight: 600 !important;
    color: var(--primary-color) !important;
    cursor: pointer;
    display: flex;
    align-items: center;
}

/* 图片预览样式 */
.image-preview-container {
    margin-top: 15px;
    padding: 15px;
    border: 2px dashed #dee2e6;
    border-radius: 8px;
    background: #f8f9fa;
    text-align: center;
}

.preview-image {
    max-width: 100%;
    max-height: 200px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    margin-bottom: 10px;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.preview-image:hover {
    transform: scale(1.02);
}

.remove-image-btn {
    background: #dc3545;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s ease;
}

.remove-image-btn:hover {
    background: #c82333;
}

/* 图片放大预览模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
}

.modal-content {
    max-width: 90%;
    max-height: 90%;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}

.modal-image {
    width: 100%;
    height: auto;
    display: block;
}

.close {
    position: absolute;
    top: 10px;
    right: 20px;
    color: white;
    font-size: 30px;
    font-weight: bold;
    cursor: pointer;
    z-index: 1001;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close:hover {
    background: rgba(0, 0, 0, 0.7);
}

/* --- 按钮样式 --- */
.form-actions {
    display: flex;
    gap: 15px;
    justify-content: flex-end;
    margin-top: 20px;
}

.btn {
    padding: 10px 25px;
    border: 1px solid transparent;
    border-radius: var(--border-radius);
    font-size: 1em;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-color-dark);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
}

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

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

.btn-danger:hover {
    background-color: #c82333;
    transform: translateY(-2px);
}

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

.btn-success:hover {
    background-color: #218838;
    transform: translateY(-2px);
}

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

.btn-warning:hover {
    background-color: #e0a800;
    transform: translateY(-2px);
}

.btn-info {
    background-color: #17a2b8;
    color: white;
}

.btn-info:hover {
    background-color: #138496;
    transform: translateY(-2px);
}

/* --- 日期选择器 (老年人友好优化) --- */
.date-picker-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.date-picker-container {
    background: white;
    border-radius: var(--border-radius);
    width: 480px; /* 增加宽度，为年月选择提供更多空间 */
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.date-picker-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px; /* 增加内边距 */
    border-bottom: 1px solid var(--border-color);
}

.date-picker-nav {
    display: flex;
    align-items: center;
    gap: 15px;
    flex: 1;
    justify-content: center;
}

.date-picker-title {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.3em;
    font-weight: 500;
}

.date-nav-btn, .date-close-btn {
    background: transparent;
    border: none;
    font-size: 1.8em; /* 增大图标 */
    cursor: pointer;
    color: var(--secondary-color);
}

.date-picker-title select {
    border: 1px solid var(--border-color);
    padding: 10px 16px; /* 增加内边距 */
    border-radius: 8px;
    font-family: var(--font-family);
    font-size: 1.2em; /* 增大字体 */
    min-width: 90px;
    text-align: center;
    background: white;
    cursor: pointer;
    transition: border-color var(--transition-speed);
}

.date-picker-title select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}

.date-picker-body {
    padding: 15px; /* 增加内边距 */
}

.date-weekdays, .date-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 8px; /* 增加间距 */
}

.weekday {
    text-align: center;
    font-weight: 500;
    color: var(--secondary-color);
    font-size: 1em; /* 增大星期字体 */
}

.date-cell {
    text-align: center;
    padding: 12px 0; /* 增加垂直内边距，扩大点击区域 */
    border-radius: 50%;
    cursor: pointer;
    transition: background-color var(--transition-speed);
    font-size: 1.1em; /* 增大日期字体 */
}

.date-cell:hover {
    background-color: #e9ecef;
}

.date-cell.other-month {
    color: #adb5bd;
}

.date-cell.today {
    font-weight: bold;
    border: 2px solid var(--primary-color); /* 加粗边框 */
}

.date-cell.selected {
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
}

.date-picker-footer {
    padding: 15px; /* 增加内边距 */
    text-align: right;
    border-top: 1px solid var(--border-color);
}

/* 当前选择日期显示样式 */
.selected-date-display {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px 15px;
    background-color: #f8f9fa;
    border-radius: 6px;
    border: 1px solid #e9ecef;
    margin: 0 15px 15px 15px;
}

.selected-date-label {
    font-size: 1em;
    color: var(--label-color);
    margin-right: 8px;
    font-weight: 500;
}

.selected-date-value {
    font-size: 1.1em;
    color: var(--primary-color);
    font-weight: 600;
    padding: 4px 8px;
    background-color: #e3f2fd;
    border-radius: 4px;
    min-width: 120px;
    text-align: center;
}

.selected-date-value:empty::before {
    content: "未选择";
    color: #6c757d;
    font-weight: normal;
}

.date-picker-footer .btn {
    font-size: 1.1em; /* 增大按钮字体 */
    padding: 12px 20px; /* 增大按钮尺寸 */
}

/* --- 响应式设计 --- */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .container {
        margin: 10px auto;
    }

    header {
        padding: 30px 20px;
    }

    .registration-form {
        padding: 20px;
    }

    .date-range {
        flex-direction: column;
        gap: 5px;
        align-items: stretch;
    }

    .form-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}