/* 通用样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

/* 问题反馈样式 */
.feedback-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
}

.feedback-modal {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
}

.feedback-header {
    background: linear-gradient(135deg, #007bff 0%, #6610f2 100%);
    color: white;
    padding: 20px;
    border-radius: 15px 15px 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.feedback-header h2 {
    margin: 0;
    font-size: 1.5em;
}

.feedback-close {
    background: none;
    border: none;
    color: white;
    font-size: 1.5em;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback-close:hover {
    opacity: 0.8;
}

.feedback-body {
    padding: 25px;
}

.feedback-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: bold;
    color: #333;
    font-size: 0.95em;
}

.form-group.required label::after {
    content: " *";
    color: #dc3545;
}

.form-group select,
.form-group textarea,
.form-group input[type="text"],
.form-group input[type="email"] {
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1em;
    transition: border-color 0.3s;
}

.form-group select:focus,
.form-group textarea:focus,
.form-group input[type="text"]:focus,
.form-group input[type="email"]:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}

.form-row {
    display: flex;
    gap: 15px;
}

.form-row .form-group {
    flex: 1;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-hint {
    font-size: 0.85em;
    color: #666;
    margin-top: 5px;
}

.feedback-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 10px;
}

.feedback-btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.feedback-btn-primary {
    background: linear-gradient(135deg, #007bff 0%, #6610f2 100%);
    color: white;
}

.feedback-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 123, 255, 0.4);
}

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

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

.feedback-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.feedback-success {
    background: #d4edda;
    color: #155724;
    padding: 15px;
    border-radius: 8px;
    border: 1px solid #c3e6cb;
    margin-bottom: 15px;
    display: none;
}

.feedback-error {
    background: #f8d7da;
    color: #721c24;
    padding: 15px;
    border-radius: 8px;
    border: 1px solid #f5c6cb;
    margin-bottom: 15px;
    display: none;
}

/* 反馈按钮样式 */
.feedback-trigger {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, #007bff 0%, #6610f2 100%);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 1.5em;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.4);
    z-index: 9999;
    transition: all 0.3s;
}

.feedback-trigger:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(0, 123, 255, 0.6);
}

@media (max-width: 768px) {
    .feedback-modal {
        width: 95%;
        margin: 20px;
    }
    
    .form-row {
        flex-direction: column;
        gap: 15px;
    }
    
    .feedback-body {
        padding: 20px;
    }
    
    .feedback-actions {
        flex-direction: column;
    }
    
    .feedback-btn {
        width: 100%;
    }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
    text-align: center;
}

.header-top {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.header-top .system-logo {
    position: absolute;
    left: 0;
    max-height: 64px;
    width: auto;
}

/* Logo 白色细描边：沿透明轮廓勾勒 0.5px 白边 */
.system-logo {
    filter: drop-shadow(0.5px 0 0 #fff) drop-shadow(-0.5px 0 0 #fff) drop-shadow(0 0.5px 0 #fff) drop-shadow(0 -0.5px 0 #fff);
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header .subtitle {
    font-size: 1.1em;
    opacity: 0.9;
    margin: 0;
    font-weight: 300;
}

.nav-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.nav-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-decoration: none;
    color: #333;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.nav-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.nav-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.card-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
}

.nav-card h2 {
    margin: 0 0 15px 0;
    font-size: 1.5em;
    color: #2c3e50;
}

.nav-card p {
    margin: 0 0 20px 0;
    color: #6c757d;
    line-height: 1.6;
}

.card-features {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.card-features span {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8em;
    font-weight: 500;
}

/* 系统信息区域 */
.system-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.info-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.info-card h3 {
    margin: 0 0 20px 0;
    color: #2c3e50;
    font-size: 1.3em;
}

.info-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.info-card li {
    padding: 8px 0;
    color: #6c757d;
    border-bottom: 1px solid #f8f9fa;
}

.info-card li:last-child {
    border-bottom: none;
}

.info-card ol {
    padding-left: 20px;
    margin: 0;
}

.info-card ol li {
    padding: 8px 0;
    color: #6c757d;
    border-bottom: 1px solid #f8f9fa;
}

.info-card code {
    background: #f8f9fa;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: #e83e8c;
}

.nav-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.2);
}

.nav-card h2 {
    color: #667eea;
    margin-bottom: 10px;
    font-size: 1.5em;
}

.nav-card p {
    color: #666;
    font-size: 1.1em;
}

.back-link {
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    transition: background 0.3s ease;
}

.back-link:hover {
    background: rgba(255, 255, 255, 0.3);
}

.loading {
    text-align: center;
    padding: 50px;
    font-size: 1.2em;
    color: #666;
}

footer {
    text-align: center;
    padding: 20px;
    color: #666;
    border-top: 1px solid #ddd;
    margin-top: 50px;
}

/* ===== 页脚 ICP 备案信息（通信管理部门要求：页面底部展示并链接至备案系统）===== */
.site-footer {
    text-align: center;
    padding: 16px 12px 20px;
    color: #888;
    font-size: 13px;
    line-height: 1.9;
    border-top: 1px solid #e5e5e5;
    margin-top: 30px;
    background: transparent;
}

.site-footer p {
    margin: 0;
}

.site-footer .icp-link,
.site-footer a {
    color: #888;
    text-decoration: none;
}

.site-footer .icp-link:hover,
.site-footer a:hover {
    color: #007bff;
    text-decoration: underline;
}

/* 大屏页：紫色渐变背景下的页脚可读性 */
.display-container .site-footer {
    color: rgba(255, 255, 255, 0.75);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    margin-top: 0;
    padding: 14px 12px 18px;
}

.display-container .site-footer .icp-link,
.display-container .site-footer a {
    color: rgba(255, 255, 255, 0.8);
}

.display-container .site-footer .icp-link:hover,
.display-container .site-footer a:hover {
    color: #fff;
}

/* 登录表单「记住我」勾选行 */
.remember-row {
    display: flex;
    align-items: center;
    padding: 2px 0;
}

/* 注意：必须压过 `.login-modal .form-group label`（它设了 display:block，会让方框退回行内基线对齐而偏高）
   故此处用更高优先级选择器 .login-modal .form-group.remember-row label */
.remember-row label,
.login-modal .form-group.remember-row label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    color: #444;
    font-weight: normal;
    cursor: pointer;
    margin: 0;
    -webkit-user-select: none;
    user-select: none;
}

/* 行高与方框高度（18px）一致，保证文字中心与方框中心在同一水平线 */
.remember-row .remember-text {
    line-height: 18px;
}

/* 自定义勾选框：与主题色一致，尺寸更大、更协调 */
.remember-row input[type="checkbox"] {
    -webkit-appearance: none;
    appearance: none;
    box-sizing: border-box;
    width: 18px;
    height: 18px;
    flex: 0 0 18px;
    align-self: center;
    margin: 0;
    padding: 0;
    border: 2px solid #c3c8d4;
    border-radius: 5px;
    background: #fff;
    cursor: pointer;
    position: relative;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.remember-row input[type="checkbox"]:hover {
    border-color: #667eea;
}

.remember-row input[type="checkbox"]:checked {
    background: #667eea;
    border-color: #667eea;
}

.remember-row input[type="checkbox"]:checked::after {
    content: "";
    position: absolute;
    left: 4px;
    top: 0px;
    width: 5px;
    height: 10px;
    border: solid #fff;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.remember-row input[type="checkbox"]:focus-visible {
    outline: 2px solid rgba(102, 126, 234, 0.45);
    outline-offset: 1px;
}

/* 按钮样式 */
button {
    background: #667eea;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1em;
    transition: background 0.3s ease;
}

button:hover {
    background: #5a6fd8;
}

button:disabled {
    background: #ccc;
    cursor: not-allowed;
}

/* 输入框样式 */
input[type="text"], input[type="number"] {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1em;
    width: 100%;
    margin-bottom: 10px;
}

input[type="text"]:focus, input[type="number"]:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 5px rgba(102, 126, 234, 0.3);
}/* 登录弹窗样式 *
/
/* 老师登录弹窗 - 学生登录风格 */
.login-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
}

.login-modal-content {
    background: white;
    padding: 30px;
    border-radius: 8px;
    width: 400px;
    max-width: 90%;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.login-modal-content h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #333;
}

.login-modal .form-group {
    margin-bottom: 15px;
}

.login-modal .form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #555;
}

.login-modal .form-group input[type="text"],
.login-modal .form-group input[type="password"] {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 15px;
    box-sizing: border-box;
    height: auto;
}

.login-modal .form-group input[type="text"]:focus,
.login-modal .form-group input[type="password"]:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 5px rgba(102, 126, 234, 0.3);
}

.login-modal .form-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 20px;
}

.login-modal .form-actions button {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s ease;
}

.login-modal .form-actions button[type="submit"] {
    background-color: #667eea;
    color: white;
}

.login-modal .form-actions button[type="submit"]:hover {
    background-color: #5a6fd8;
}

.login-modal .form-actions button[type="button"] {
    background-color: #6c757d;
    color: white;
}

.login-modal .form-actions button[type="button"]:hover {
    background-color: #5a6268;
}

.login-modal .login-tips {
    margin: 10px 0;
    text-align: center;
}

.login-modal .login-tips small {
    color: #666;
    font-size: 12px;
}

/* 老师登录 - 学生风格弹窗 */
.teacher-login-styled .teacher-login-header {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    padding: 25px 30px;
    text-align: center;
}

.teacher-login-styled .teacher-login-header h2 {
    margin: 0;
    color: white;
    font-size: 1.6em;
    font-weight: 600;
}

.teacher-login-styled form {
    padding: 30px;
}

.teacher-login-styled .form-group {
    margin-bottom: 18px;
}

.teacher-login-styled .form-group input[type="text"],
.teacher-login-styled .form-group input[type="password"] {
    width: 100%;
    padding: 15px;
    border: 2px solid #dee2e6;
    border-radius: 8px;
    font-size: 1.1em;
    text-align: center;
    transition: border-color 0.3s ease;
    box-sizing: border-box;
}

.teacher-login-styled .form-group input[type="text"]:focus,
.teacher-login-styled .form-group input[type="password"]:focus {
    outline: none;
    border-color: #28a745;
    box-shadow: 0 0 8px rgba(40, 167, 69, 0.2);
}

.teacher-login-styled .login-tips {
    background: #e7f3ff;
    padding: 12px 15px;
    border-radius: 8px;
    border-left: 4px solid #28a745;
    margin-bottom: 20px;
}

.teacher-login-styled .login-tips p {
    margin: 0;
    color: #155724;
    font-size: 0.9em;
}

.teacher-login-styled .form-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-top: 25px;
}

.teacher-login-styled .form-actions button[type="submit"] {
    flex: 1;
    padding: 14px 20px;
    font-size: 1.15em;
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.teacher-login-styled .form-actions button[type="submit"]:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.3);
}

.teacher-login-styled .form-actions button[type="button"] {
    flex: 1;
    padding: 14px 20px;
    font-size: 1.15em;
    font-weight: bold;
    border: 2px solid #dee2e6;
    border-radius: 8px;
    background: white;
    color: #6c757d;
    cursor: pointer;
    transition: all 0.3s ease;
}

.teacher-login-styled .form-actions button[type="button"]:hover {
    background: #f8f9fa;
    border-color: #c8ccd0;
}