body, table, th, td {
    font-family: "Noto Sans CJK SC", "Noto Sans JP", "Noto Sans", "PingFang SC", "Hiragino Sans", "Microsoft YaHei", Arial, sans-serif;
}
/* Grouped font styles for kana, romanji, hint, and sources */
.romanji-char,
.jp-char,
.hint-char,
.hiragana-source,
.katakana-source {
    font-size: 17px;
    font-weight: bold;
}
.example-word {
    font-size: 15px;
    font-weight: bold;
}
body {
    margin: 0;
}
table {
    border-collapse: collapse;
    width: 100%;
    max-width: 1100px;
    min-width: 1100px;
    margin: 0 auto;
}
th,
td {
    border: 1px solid #ddd;
    text-align: center;
    padding: 2px;
}
th {
    background-color: #f2f2f2;
}
.column-header,
.row-header {
    font-weight: bold;
    background-color: #e6e6e6;
}
.row-header {
    width: 48px;
    min-width: 40px;
    max-width: 60px;
    text-align: center;
    white-space: nowrap;
}
.sub-row {
    border-top: 1px dashed #ccc;
    height: 30px;
    min-height: 30px;
}
.sub-row:first-child {
    border-top: none;
}
.sub-col {
    border-left: 1px dashed #ccc;
    width: 3.33%;
}
.sub-col:first-child {
    border-left: none;
}
h1 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
}
.main-column-separator {
    border-left: 2px solid #999;
}
.main-row-separator {
    border-top: 2px solid #999;
}
.major-section-separator {
    border-left: 4px solid #333;
}
.button-container {
    display: flex;
    justify-content: center;
    margin: 10px auto 20px;
    gap: 10px;
}
.toggle-btn {
    padding: 8px 16px;
    background-color: #FB8C00;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.toggle-btn:hover {
    background-color: #EF6C00;
}
.hidden {
    opacity: 0;
    transition: none !important;
}
.knowledge-section {
    max-width: 800px;
    margin: 0 auto 10px;
    overflow: hidden;
    max-height: 0;
    background: #f8f9fa;
    border-radius: 8px;
    margin-top: 0;
    transition: max-height 0.0s ease, margin 0.0s ease;
}
.knowledge-section:not([style*="max-height"]) {
    margin-top: 0;
    margin-bottom: 0;
}
.knowledge-content {
    padding: 15px;
    border: 1px solid #ddd;
}
.knowledge-btn-container {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 10px auto 5px;
}
.knowledge-btn {
    font-weight: bold;
    padding: 5px 12px;
    background-color: #3949AB;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9em;
    min-width: 120px;
    text-align: center;
    transition: background-color 0.1s;
}
.knowledge-btn:hover {
    background-color: #303F9F;
}
.knowledge-btn.active {
    background-color: #1A237E;
    border-color: #0D1859;
}
.main-container {
    max-width: 800px;
    margin: 20px auto;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
}
.main-desc {
    margin: 0 0 12px;
    color: #333;
}
.main-list {
    margin: 0 0 12px;
    padding-left: 20px;
}
.main-list li {
    margin-bottom: 8px;
}
.knowledge-title {
    margin-top: 0;
    color: #333;
    font-size: 1.1em;
}
.accent-high {
    border-top: 1px solid red;
    padding-top: 2px;
}
.accent-low {
    border-bottom: 1px solid blue;
    padding-bottom: 2px;
}
.spacer {
    height: 15px;
}
.hiragana-char {
    color: #8B4500 !important;
}
.katakana-char {
    color: #800000 !important;
}
.romanji-char {
    color: #000 !important;
}
.hint-hiragana {
    color: #FFA500 !important; /* 普通橙色 */
}
.hint-katakana {
    color: #FF0000 !important; /* 普通红色 */
}
.hiragana-source {
    color: #003366 !important; /* 深蓝色 */
}
.katakana-source {
    color: #006400 !important; /* 深绿色 */
}
.accent-mark {
    position: relative;
    font-size: 15px;
    font-weight: bold;
    padding: 2px 0;
}
.table-cell {
    width: 10%;
    height: 30px;
}
.menu-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: #1A237E;
    padding: 0 32px;
    height: 56px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    margin-bottom: 0;
}
.menu-logo {
    color: #fff;
    font-size: 1.3em;
    font-weight: bold;
    letter-spacing: 1px;
}
.menu-links {
    list-style: none;
    display: flex;
    gap: 24px;
    margin: 0;
    padding: 0;
}
.menu-links li a {
    color: #fff;
    text-decoration: none;
    font-size: 1em;
    transition: color 0.2s;
}
.menu-links li a:hover {
    color: #ffd700;
}
.pinyin-char {
    color: gray;
    font-size: 0.95em;
    display: block;
    text-align: center;
}
.button-container button {
    font-weight: bold;
}