/* ===== リセット & ベーススタイル ===== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    width: 100%;
    overflow-x: hidden; /* 横スクロール禁止 */
}

body {
    line-height: 1.6;
    background: linear-gradient(to bottom, #ffffff 80%, #d8d8d8, #7d7d7d, #000000);
    background-attachment: fixed;
    background-size: cover;
    color: #333;
    padding: 20px;
    font-family: 'Hiragino Mincho Pro', serif;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ===== ヘッダー ===== */
header {
    background: linear-gradient(to bottom, #ffffff 0%, #ffffff 50%,#e0f7ff00 98%);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 0;
    text-align: center;
    font-weight: bold;
    z-index: 10;
    font-family: 'Hiragino Mincho Pro', serif;
}

header h1 {
    font-size: 2em;
    color: #333;
}

header nav a {
    color: #454545;
    text-decoration: none;
    font-weight: normal;
    padding: 8px 16px;
    border-radius: 20px;
    transition: background-image 0.6s ease, color 0.3s, transform 0.3s;
}

header nav a:hover {
    color: #fff;
    background-image: radial-gradient(ellipse, rgba(0, 0, 0, 0.7) 20%, rgba(0, 0, 0, 0) 70%);
    transform: scale(1.05);
    text-decoration: none;
}

/* ===== メインコンテンツ ===== */
main {
    flex-grow: 1;
    width: 90%;
    max-width: 1200px;
    margin: 120px auto 0; /* headerの下に空間 */
    padding: 20px;
    text-align: center;
    overflow-x: hidden;
}

/* ===== リンクスタイル ===== */
a {
    color: #646464;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: normal;
    text-decoration: none;
    transition: background-color 0.3s, color 0.3s;
}

a:hover {
    color: #999;
    text-decoration: underline;
}

a.nav-link {
    color: #000;
    position: relative;
}

a.nav-link:hover {
    color: #fff;
    background-image: radial-gradient(ellipse, rgba(0, 0, 0, 0.7) 20%, rgba(0, 0, 0, 0) 80%);
    transform: scale(1.05);
    text-decoration: none;
}

/* ===== 画像センター配置 ===== */
.center-image {
    display: flex;
    justify-content: center;
    margin-top: 160px;
}

.center-image img {
    width: 30%;
    height: auto;
}

/* ===== 記事カード ===== */
.article {
    width: 100%;
    padding: 10px;
    margin: 5px auto;
    border-radius: 10px;
    font-weight: bold;
    font-size: 0.9em;
    transition: transform 0.3s, box-shadow 0.3s;
}

.article:hover {
    color: #fff;
    background-image: radial-gradient(ellipse, rgba(0, 0, 0, 0.7) 10%, rgba(0, 0, 0, 0) 25%);
    transform: scale(1.05);
    text-decoration: none;
}

.article h2 {
    font-size: 0.9em;
    padding: 10px;
    border-radius: 5px;
    font-weight: normal;
}

.article p {
    font-size: 16px;
    line-height: 1.6;
    color: #f7f7f7;
}

/* ===== フッター ===== */
footer {
    color: #dcdcdc;
    font-size: 0.1em;
    text-align: center;
    padding: 30px 0;
    margin-top: 20px;
    opacity: 0.8;
}

/* ===== フェードイン効果 ===== */
.fade-in {
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

.fade-in.visible {
    opacity: 1;
}

/* ===== モーダル ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.3s ease;
}

.modal-content {
    background-color: rgba(255, 255, 255, 0.9);
    padding: 20px 40px;
    border-radius: 12px;
    width: 500px;
    height: 500px;
    overflow-y: auto;
    position: relative;
    font-size: 0.85em;
    animation: fadeIn 0.3s ease;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.modal-content img {
    display: block;
    margin: 20px auto 0;  /* ← 上に余白、左右中央寄せ */
    max-width: 50%;
    height: auto;
    border-radius: 5px;
}

.modal-content h2 {
    margin-bottom: 20px; /* タイトルと本文の間の余白 */
    font-size: 1.5em;    /* タイトルのフォントサイズ */
    color: #333;         /* タイトルの色 */
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.close {
    position: absolute;
    top: 10px;
    right: 10px;
    font-size: 1.5em;
    font-weight: bold;
    color: #333;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close:hover {
    color: #acacac;
}

/* ===== アニメーション ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* ===== カスタムスクロールバー ===== */
::-webkit-scrollbar {
    width: 0.5px;
}

::-webkit-scrollbar-track {
    background: #585858;
    border-radius: 10px;
}

::-webkit-scrollbar-thumb {
    background: #999;
    border-radius: 10px;
}