#return-btn {
    position: absolute; /* 绝对定位 */
    top: 20px; /* 距离顶部 20px */
    left: 20px; /* 距离左侧 20px */
    padding: 12px 24px; /* 内边距 */
    font-size: 1rem; /* 字体大小 */
    cursor: pointer; /* 鼠标悬停时显示为手型 */
    background-color: #1565C0; /* 按钮背景颜色 */
    color: #E3F2FD; /* 按钮文字颜色 */
    border: none; /* 按钮边框样式 */
    border-radius: 20px; /* 按钮圆角大小 */
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3); /* 按钮阴影 */
    transition: all 0.2s ease; /* 背景颜色和缩放的过渡效果 */
    z-index: 1001; /* 按钮层级 */
}

#return-btn:hover {
    background-color: #1976D2; /* 悬停时的背景颜色 */
    transform: translateY(-1px); /* 悬停时向上移动 1px */
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4); /* 悬停时的阴影效果 */
}

body {
    font-family: 'Roboto', 'HarmonyOS Sans SC', sans-serif;
    margin: 0;
    padding: 0;
    background: #0D223A;
    color: #E3F2FD;
    overflow: auto;
}

body::-webkit-scrollbar {
    display: none;
}

.top-btn-group {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    flex-direction: row;
    gap: 20px;
    z-index: 1001;
}

#fullscreen-btn, #settings-btn, #reminder-settings-btn {
    padding: 12px 24px;
    font-size: 1rem;
    cursor: pointer;
    background-color: #1565C0;
    color: #E3F2FD;
    border: none;
    border-radius: 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.3);
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
}

#fullscreen-btn::before {
    content: "fullscreen";
    font-family: 'Material Icons';
    font-size: 20px;
    margin-right: 4px;
}

#settings-btn::before {
    content: "settings";
    font-family: 'Material Icons';
    font-size: 20px;
    margin-right: 4px;
}

#reminder-settings-btn::before {
    content: "notifications";
    font-family: 'Material Icons';
    font-size: 20px;
    margin-right: 4px;
}

#fullscreen-btn:hover, #settings-btn:hover, #reminder-settings-btn:hover {
    background-color: #1976D2;
    transform: translateY(-1px);
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

.container {
    padding: 24px;
    max-width: 1400px;
    margin: auto;
    background-color: #102840;
    border-radius: 28px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

h1 {
    font-size: 3.5rem;
    font-weight: 400;
    text-align: left;
    margin-bottom: 16px;
    color: #E3F2FD;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

#room {
    font-size: 3.5rem;
    font-weight: 400;
    color: #E3F2FD;
    margin-left: 20px;
}

#message {
    font-size: 1.8rem;
    color: #90CAF9;
    margin-bottom: 24px;
}

.content {
    display: flex;
    justify-content: space-between;
    gap: 24px;
}

.left-column, .right-column {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.left-column {
    width: 45%;
}

.right-column {
    width: 50%;
}

.clock-section, .info-section, .right-column {
    background-color: #183A5A;
    padding: 24px;
    border-radius: 28px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

#current-time {
    font-size: 8rem;
    text-align: center;
    color: #90CAF9;
    margin: 0;
    font-weight: 400;
}

#current-subject, #exam-timing, #remaining-time, #status {
    font-size: 3rem;
    margin: 16px 0;
    text-align: left;
    color: #E3F2FD;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin-top: 24px;
    background-color: #183A5A;
    border-radius: 16px;
    overflow: hidden;
}

th, td {
    padding: 1px;
    font-size: 1.8rem;
    text-align: center;
    border-bottom: 1px solid #1976D2;
}

th {
    background-color: #1976D2;
    color: #E3F2FD;
    font-weight: 500;
}

tr:hover {
    background-color: #1565C0;
}

.exam-status-tag {
    padding: 2px 4px;
    border-radius: 3px;
    font-size: 1.2rem;
    font-weight: 500;
}

.exam-status-进行中 {
    background-color: #1565C0;
    color: #B3E5FC;
}

.exam-status-即将开始 {
    background-color: #1976D2;
    color: #E3F2FD;
}

.exam-status-已结束 {
    background-color: #37474F;
    color: #B0BEC5;
}

.exam-status-未开始 {
    background-color: #102840;
    color: #90CAF9;
}

#settings-modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(13, 34, 58, 0.8);
    backdrop-filter: blur(8px);
}

#settings-modal-content {
    background: #102840;
    padding: 32px 48px 32px 32px;
    margin: 32px auto;
    border-radius: 28px;
    width: 600px;
    max-height: 60vh;
    overflow-y: auto;
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

#settings-modal-content::-webkit-scrollbar {
    width: 8px;
}

#settings-modal-content::-webkit-scrollbar-track {
    background: transparent;
    margin: 4px;
}

#settings-modal-content::-webkit-scrollbar-thumb {
    background: #1976D2;
    border-radius: 8px;
    border: 2px solid #102840;
}

#settings-modal-content::-webkit-scrollbar-thumb:hover {
    background: #1565C0;
}

#settings-modal-content h3 {
    margin: 0 0 24px;
    color: #E3F2FD;
    font-size: 24px;
    font-weight: 400;
}

#settings-modal-content label {
    display: flex;
    align-items: center;
    gap: 16px;
    margin: 16px 0;
    font-size: 16px;
    color: #E3F2FD;
}

#settings-modal-content input[type="number"],
#settings-modal-content input[type="text"] {
    font-size: 1.8rem;
    padding: 12px 16px;
    margin: 8px 0 24px;
    width: 100%;
    box-sizing: border-box;
    border: 2px solid #1976D2;
    border-radius: 12px;
    background-color: #183A5A;
    color: #E3F2FD;
    transition: all 0.2s ease;
}

#settings-modal-content input:focus {
    outline: none;
    border-color: #90CAF9;
    background-color: #1565C0;
}

.button-group {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
    margin-top: 32px;
    position: relative;
    background-color: #102840;
    padding: 16px 0;
    border-top: 1px solid #1976D2;
}

#save-settings-btn, #close-settings-btn {
    padding: 12px 24px;
    border-radius: 20px;
    font-size: 16px;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

#save-settings-btn {
    background-color: #90CAF9;
    color: #0D223A;
}

#close-settings-btn {
    background-color: #1565C0;
    color: #E3F2FD;
}

#save-settings-btn:hover, #close-settings-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

#save-settings-btn::before {
    content: "✓";
    font-size: 18px;
}

#close-settings-btn::before {
    content: "✕";
    font-size: 18px;
}

.error-container {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: #0D223A;
    color: #90CAF9;
    padding: 16px 24px;
    border-radius: 16px;
    display: none;
    z-index: 10001;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    animation: slideUp 0.3s ease;
}

.switch {
    position: relative;
    display: inline-block;
    width: 52px;
    height: 32px;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #1976D2;
    transition: .3s;
    border-radius: 16px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 24px;
    width: 24px;
    left: 4px;
    bottom: 4px;
    background-color: #E3F2FD;
    transition: .3s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: #90CAF9;
}

input:checked + .slider:before {
    transform: translateX(20px);
    background-color: #0D223A;
}

.config-file-container {
    margin: 24px 0;
    padding: 24px;
    border: 2px solid #1976D2;
    border-radius: 20px;
    background-color: #102840;
    transition: all 0.2s ease;
}

.config-file-container:hover {
    border-color: #90CAF9;
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.config-file-container input[type="file"] {
    max-width: 100%;
    width: auto;
    box-sizing: border-box;
    padding: 12px;
    border: 2px dashed #1976D2;
    border-radius: 16px;
    background-color: #183A5A;
    color: #E3F2FD;
    cursor: pointer;
    transition: all 0.2s ease;
}

.config-file-container input[type="file"]::-webkit-file-upload-button {
    padding: 8px 16px;
    margin-right: 12px;
    background-color: #1976D2;
    color: #E3F2FD;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.config-file-container input[type="file"]::-webkit-file-upload-button:hover {
    background-color: #1565C0;
}

.file-hint {
    margin-top: 12px;
    font-size: 14px;
    color: #90CAF9;
    line-height: 1.5;
}

.config-control-btn {
    margin-top: 20px;
    padding: 12px 28px;
    background-color: #1976D2;
    color: #E3F2FD;
    border: none;
    border-radius: 24px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.config-control-btn:hover {
    background-color: #1565C0;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.4);
}

/* 导出按钮样式 */
#export-config-btn {
    margin-top: 12px;
    padding: 12px 28px;
    background-color: #1976D2;
    color: #E3F2FD;
    border: none;
    border-radius: 24px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

#export-config-btn:hover {
    background-color: #1565C0;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(208,188,255,0.15);
}

.theme-toggle-container {
    margin: 24px 0;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

#theme-select {
    width: 100%;
    padding: 12px 16px;
    font-size: 1.2rem;
    background-color: #183A5A;
    color: #E3F2FD;
    border: 2px solid #1976D2;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='lightblue' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 16px;
}

#theme-select:hover {
    background-color: #1565C0;
    border-color: #90CAF9;
}

#theme-select:focus {
    outline: none;
    border-color: #90CAF9;
    background-color: #1565C0;
}

#theme-select option {
    background-color: #183A5A;
    color: #E3F2FD;
    padding: 12px;
}

#theme-select option:hover,
#theme-select option:focus {
    background-color: #1565C0;
}

.theme-toggle-container label {
    font-size: 16px;
    color: #E3F2FD;
    margin-bottom: 8px;
}

.reminder-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(13, 34, 58, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.5s ease;
    backdrop-filter: blur(8px);
    z-index: 9999;
}

.reminder-overlay.show {
    opacity: 1;
    visibility: visible;
}

.reminder-content {
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.reminder-title {
    font-size: 5rem;
    color: #90CAF9;
    margin-bottom: 2rem;
}

.reminder-subtitle {
    font-size: 3rem;
    color: #1976D2;
}

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

.info-toggle-btn {
    position: absolute;
    right: 20px;
    top: 20px;
    background-color: #1565C0;
    color: #E3F2FD;
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    z-index: 1;
}

.info-toggle-btn:hover {
    background-color: #1976D2;
    transform: translateY(-1px);
}

.info-toggle-btn .material-icons {
    font-size: 24px;
}

#paper-info {
    font-size: 3rem;
    margin: 16px 0;
    text-align: left;
    color: #E3F2FD;
}

#exam-papers, #answer-sheets {
    margin: 10px 0;
}

.paper-count-container {
    margin: 20px 0;
}

.paper-input-group {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 10px 0;
    font-size: 2.5rem;
}

.count-btn-group {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin-right: 8px;
}

.count-control {
    display: flex;
    align-items: center;
    gap: 5px;
}

.count-control input {
    width: 60px;
    padding: 5px;
    font-size: 2rem;
    text-align: center;
    background-color: #183A5A;
    color: #E3F2FD;
    border: 2px solid #1976D2;
    border-radius: 8px;
}

.count-btn {
    width: 24px;
    height: 24px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.count-btn .material-icons {
    font-size: 16px;
}

.count-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: none;
    border-radius: 50%;
    background-color: #1565C0;
    color: #E3F2FD;
    cursor: pointer;
    transition: all 0.2s ease;
}

.count-btn:hover {
    background-color: #1976D2;
    transform: translateY(-1px);
}

.count-btn .material-icons {
    font-size: 20px;
}

.info-section {
    position: relative;
}

.info-toggle-btn {
    position: absolute;
    right: 0;
    top: 0;
    background-color: #1565C0;
    color: #E3F2FD;
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    z-index: 2;
}

.info-toggle-btn:hover {
    background-color: #1976D2;
    transform: translateY(-1px);
}

.info-toggle-btn .material-icons {
    font-size: 24px;
}

/* 优化提醒设置弹窗样式 */
#reminder-modal.settings-modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(13, 34, 58, 0.8);
    backdrop-filter: blur(8px);
}

#reminder-modal-content.settings-panel {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 800px;
    max-width: 95vw;
    max-height: 80vh;
    overflow-y: auto;
    background: #102840;
    border-radius: 28px;
    box-shadow: 0 8px 24px rgba(25,118,210,0.32);
    padding: 32px 48px 32px 32px;
}

#reminder-modal-content.settings-panel h3 {
    margin-top: 0;
    margin-bottom: 24px;
    font-size: 24px;
    font-weight: 400;
    color: #E3F2FD;
}

.reminder-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin-bottom: 24px;
    background: #183A5A;
    border-radius: 16px;
    overflow: hidden;
    table-layout: fixed;
}

.reminder-table th, .reminder-table td {
    padding: 16px 8px;
    font-size: 1.4rem;
    text-align: center;
    border-bottom: 1px solid #1976D2;
    vertical-align: middle;
    word-break: break-all;
}

.reminder-table th {
    background: #1976D2;
    color: #E3F2FD;
    font-weight: 500;
}

.reminder-table tr:last-child td {
    border-bottom: none;
}

.reminder-table th:nth-child(1),
.reminder-table td:nth-child(1) {
    width: 50%;
    text-align: left;
    padding-left: 20px;
}
.reminder-table th:nth-child(2),
.reminder-table td:nth-child(2) {
    width: 15%;
}
.reminder-table th:nth-child(3),
.reminder-table td:nth-child(3) {
    width: 25%;
}
.reminder-table th:nth-child(4),
.reminder-table td:nth-child(4) {
    width: 10%;
}

.reminder-table .action-btn {
    padding: 8px 18px;
    border-radius: 16px;
    background: #1565C0;
    color: #E3F2FD;
    border: none;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background 0.2s;
    margin: 0 auto;
    display: block;
}

.reminder-table .action-btn:hover {
    background: #1976D2;
}

.reminder-btn {
    padding: 8px 18px;
    border-radius: 16px;
    background: #37474F;
    color: #90CAF9;
    border: none;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background 0.2s;
    margin: 0 auto;
    display: block;
}

.reminder-btn:hover {
    background: #1976D2;
}

.reminder-select {
    width: 100%;
    padding: 8px 12px;
    font-size: 1.1rem;
    border: 2px solid #1976D2;
    border-radius: 10px;
    background: #183A5A;
    color: #E3F2FD;
    transition: border-color 0.2s;
    outline: none;
}

.reminder-select:focus {
    border-color: #90CAF9;
}

.reminder-time-input {
    width: 80px;
    padding: 8px 12px;
    font-size: 1.1rem;
    border: 2px solid #1976D2;
    border-radius: 10px;
    background: #183A5A;
    color: #E3F2FD;
    transition: border-color 0.2s;
    outline: none;
    text-align: center;
}

.reminder-time-input:focus {
    border-color: #90CAF9;
}

#reminder-modal-content .button-group {
    background: #102840;
    border-top: 1px solid #1976D2;
    margin-top: 32px;
    padding: 16px 0 0 0;
    display: flex;
    justify-content: flex-end;
    gap: 16px;
    border-radius: 0 0 28px 28px;
}

.reminder-btn-group,
#reminder-modal-content .button-group {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
    margin-top: 32px;
    background: #102840;
    border-top: 1px solid #1976D2;
    padding: 16px 0 0 0;
    border-radius: 0 0 28px 28px;
}

#save-reminder-btn, #close-reminder-btn, #stop-audio-btn {
    padding: 12px 24px;
    border-radius: 20px;
    font-size: 16px;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

#save-reminder-btn {
    background-color: #90CAF9;
    color: #0D223A;
}

#close-reminder-btn {
    background-color: #1565C0;
    color: #E3F2FD;
}

#stop-audio-btn {
    background-color: #37474F;
    color: #90CAF9;
}

#save-reminder-btn:hover, #close-reminder-btn:hover, #stop-audio-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
}

#stop-audio-btn:hover {
    background-color: #1976D2;
    color: #E3F2FD;
}