body {
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    margin: 0;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background-color: #fff;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    color: #2c3e50;
    font-size: 1.6em;
    margin-bottom: 25px;
    border-bottom: 2px solid #3498db; /* 知的な青 */
    padding-bottom: 10px;
}

/* 論文解説エリアのデザイン */
.science-box {
    background-color: #e8f4f8;
    border-left: 5px solid #3498db;
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 25px;
    font-size: 0.95em;
}

.science-title {
    font-weight: bold;
    color: #2980b9;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
}

.ref-link {
    font-size: 0.8em;
    color: #7f8c8d;
    margin-top: 8px;
    text-align: right;
}

.intro-text {
    text-align: center;
    margin-bottom: 20px;
    font-size: 0.95em;
}

.input-area {
    background-color: #fafafa;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    margin-bottom: 25px;
}

.input-group-row {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 15px 0;
}

.input-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

input[type="number"] {
    width: 60px;
    padding: 10px;
    font-size: 1.2em;
    text-align: center;
    border: 1px solid #ccc;
    border-radius: 5px;
}

button#calc-btn {
    width: 100%;
    padding: 15px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s;
    box-shadow: 0 4px 0 #2980b9;
}

button#calc-btn:hover {
    background-color: #2980b9;
    transform: translateY(2px);
    box-shadow: 0 2px 0 #2980b9;
}

/* 結果エリアのデザイン */
.result-box {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 15px;
    text-align: center;
}

.new-science {
    background-color: #dbfaf2; /* 成功・ポジティブな薄緑 */
    border: 2px solid #2ecc71;
    color: #27ae60;
}

.old-theory {
    background-color: #f2f2f2;
    color: #7f8c8d;
    border: 1px dashed #bdc3c7;
}

.label {
    display: block;
    font-size: 0.85em;
    font-weight: bold;
    margin-bottom: 5px;
    opacity: 0.8;
}

.age-display {
    font-size: 2.5em;
    font-weight: bold;
    line-height: 1.2;
}

.age-display-small {
    font-size: 1.2em;
}

.comment {
    font-size: 0.85em;
    margin-top: 10px;
    color: #27ae60;
}

.back-link {
    text-align: center;
    margin-top: 30px;
    font-size: 0.9em;
}