/* --- 基本設定 --- */
:root {
    --bg-color: #0c0c0c;
    --text-color: #ffffff;
    --accent-color: #00ffff;
    --font-mincho: "游明朝", YuMincho, "Hiragino Mincho ProN W3", "HG明朝E", "ＭＳ Ｐ明朝", "MS PMincho", serif;
    --font-gothic: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-gothic);
    background-image: radial-gradient(circle at 50% 50%, #1a1a1a 0%, #0c0c0c 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    text-align: center;
    padding: 20px;
    max-width: 600px;
    width: 100%;
}

.logo-image {
    width: 100%;
    max-width: 400px;
    height: auto;
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.3));
    margin-bottom: 40px;
}

.profile-section {
    margin-bottom: 50px;
}

.owner-name {
    font-family: var(--font-mincho);
    font-size: 1.2rem;
    letter-spacing: 0.2em;
    margin-bottom: 10px;
    color: #cccccc;
}

.owner-id {
    font-size: 2rem;
    font-weight: bold;
    letter-spacing: 0.1em;
    margin: 0;
    text-shadow: 0 0 5px var(--accent-color);
}

.link-button {
    display: inline-block;
    text-decoration: none;
    color: var(--bg-color);
    background-color: var(--text-color);
    padding: 15px 30px;
    border-radius: 4px;
    font-weight: bold;
    letter-spacing: 0.05em;
    transition: all 0.3s ease;
    border: 2px solid var(--text-color);
}

.link-button:hover {
    background-color: transparent;
    color: var(--accent-color);
    border-color: var(--accent-color);
    box-shadow: 0 0 15px var(--accent-color);
}

.link-button::before {
    content: '𝕏';
    margin-right: 10px;
    font-size: 1.2em;
    vertical-align: middle;
}

footer {
    position: absolute;
    bottom: 20px;
    width: 100%;
    text-align: center;
    font-size: 0.8rem;
    color: #666;
}

@media (max-width: 480px) {
    .logo-image { max-width: 80%; margin-bottom: 30px; }
    .owner-id { font-size: 1.5rem; }
    .link-button { width: 80%; padding: 12px 20px; }
}