* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    padding: 20px;
    background-color: #f0f2f5;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    margin-bottom: 20px;
    color: #333;
    font-size: 20px;
}

.page-info {
    text-align: center;
    color: #666;
    margin: 10px 0;
    font-size: 16px;
}

.level-selector {
    text-align: center;
    margin: 15px 0;
    color: #666;
}

.level-selector select {
    margin-left: 10px;
    padding: 8px 20px;
    font-size: 16px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.level-selector select:hover {
    border-color: #40a9ff;
}

.level-selector select:focus {
    outline: none;
    border-color: #1890ff;
    box-shadow: 0 0 0 2px rgba(24, 144, 255, 0.2);
}

.characters-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin: 20px 0;
}

.character-card {
    position: relative;
    aspect-ratio: 1;
    cursor: pointer;
}

/* 田字格样式 */
.character-box {
    width: 100%;
    height: 100%;
    position: relative;
    border: 1px solid #ddd;
    display: flex;
    align-items: center;
    justify-content: center;
}

.character-box::before,
.character-box::after {
    content: '';
    position: absolute;
    background-color: #ddd;
}

.character-box::before {
    width: 100%;
    height: 1px;
    top: 50%;
}

.character-box::after {
    width: 1px;
    height: 100%;
    left: 50%;
}

.character {
    font-size: 48px;
    z-index: 1;
    transition: color 0.3s ease;
}

.character.known {
    color: #52c41a;
}

.choice-buttons {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.choice-btn {
    padding: 8px 16px;
    border: 1px solid #ddd;
    background-color: #fff;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.choice-btn:hover {
    background-color: #f0f0f0;
}

.choice-btn.selected {
    background-color: #1890ff;
    color: white;
    border-color: #1890ff;
}

.controls {
    text-align: center;
    margin-top: 20px;
}

.submit-btn {
    padding: 10px 24px;
    font-size: 16px;
    background-color: #1890ff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.submit-btn:hover {
    background-color: #40a9ff;
}

.result {
    margin-top: 20px;
    padding: 20px;
    background-color: #f6ffed;
    border: 1px solid #b7eb8f;
    border-radius: 4px;
}

.result h2 {
    color: #52c41a;
    margin-bottom: 10px;
}

.hidden {
    display: none;
}

.navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.nav-btn {
    padding: 12px 40px;
    font-size: 16px;
    background-color: #1890ff;
    color: white;
    border: none;
    border-radius: 24px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.nav-btn:hover {
    background-color: #40a9ff;
}

.nav-btn:disabled {
    background-color: #d9d9d9;
    cursor: not-allowed;
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 20px 0;
}

.action-btn {
    padding: 8px 16px;
    font-size: 14px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.recognize-all {
    background-color: #f6ffed;
    border: 1px solid #b7eb8f;
    color: #52c41a;
}

.recognize-all:hover {
    background-color: #d9f7be;
}

.restart {
    background-color: #f0f2f5;
    border: 1px solid #d9d9d9;
    color: #666;
}

.restart:hover {
    background-color: #e6e6e6;
}

.parent-tip {
    text-align: center;
    margin-top: 30px;
    padding: 15px;
    color: #666;
    font-size: 14px;
}

.parent-tip .highlight {
    color: #52c41a;
}

.complete-test {
    background-color: #1890ff;
    color: white;
    display: none;
}

.complete-test:hover {
    background-color: #40a9ff;
}

.reading {
    background-color: #1890ff;
    color: white;
    border: none;
}

.reading:hover {
    background-color: #40a9ff;
}

.test-report {
    margin-top: 0;
    padding: 30px;
    background-color: #f6ffed;
    border: 1px solid #b7eb8f;
    border-radius: 8px;
}

.test-report h3 {
    color: #52c41a;
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
}

.test-report h4 {
    color: #333;
    margin: 20px 0 15px;
    font-size: 18px;
}

.report-stats {
    margin: 20px 0;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.report-stats p {
    margin: 12px 0;
    color: #333;
    font-size: 16px;
    line-height: 1.8;
}

.chars-list {
    margin-top: 20px;
}

.known-chars,
.unknown-chars {
    margin-top: 20px;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.chars-list p {
    line-height: 2;
    color: #333;
    font-size: 16px;
    word-break: break-all;
    text-align: justify;
}

.report-actions {
    margin-top: 30px;
    text-align: center;
    display: flex;
    justify-content: center;
    gap: 20px;
}

.report-actions .action-btn {
    padding: 12px 30px;
    font-size: 16px;
    border-radius: 24px;
    min-width: 120px;
}