body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #181a1b;
    color: #e8e6e3;
    transition: background-color 0.3s, color 0.3s;
}

body.light-mode {
    background-color: #f8f9fa;
    color: #000000;
}

header h1 {
    text-align: center;
    padding: 20px 0;
    background-color: #202324;
    color: #e8e6e3;
    margin: 0;
}

body.light-mode header h1 {
    background-color: #e0e0e0;
    color: #000;
}

.container {
    display: flex;
    min-height: 80vh;
}

.left-panel {
    width: 200px;
    padding: 20px;
    background-color: #1f2223;
}

body.light-mode .left-panel {
    background-color: #f0f0f0;
}

.left-panel button {
    display: block;
    width: 100%;
    margin-bottom: 12px;
    padding: 10px;
    font-size: 16px;
    cursor: pointer;
    background-color: #2d3031;
    color: #e8e6e3;
    border: 1px solid #3c3f41;
}

body.light-mode .left-panel button {
    background-color: #ddd;
    color: #000;
    border: 1px solid #aaa;
}

.main-content {
    flex: 1;
    padding: 20px;
    overflow-x: auto;
}

table {
    border-collapse: collapse;
    width: 100%;
    max-width: 800px;
    margin: 0 auto 30px auto;
}

th, td {
    border: 1px solid #3c3f41;
    padding: 8px;
    text-align: center;
}

input[type="text"] {
    width: 90%;
    padding: 6px;
    box-sizing: border-box;
    font-size: 14px;
    background-color: #202324;
    color: #e8e6e3;
    border: 1px solid #3c3f41;
}

body.light-mode input[type="text"] {
    background-color: #fff;
    color: #000;
    border: 1px solid #aaa;
}

table tbody tr td:nth-child(2) input {
    background-color: #2c2f30;
    color: #c8c6c3;
    border: 1px solid #3c3f41;
    cursor: not-allowed;
}

body.light-mode table tbody tr td:nth-child(2) input {
    background-color: #d3d3d3;
    color: #555;
    border: 1px solid #aaa;
}

a, a:visited {
    color: #3391ff;
    text-decoration: none;
}

body.light-mode a, body.light-mode a:visited {
    color: blue;
    text-decoration: none;
}

.explain {
    font-weight: bold;
    cursor: help;
    color: #337dff
}

body.light-mode .explain {
    color: blue;
}