/* --- 全体のスタイル --- */
body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background-color: #0a0a1a;
    color: #e0e0e0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* --- 動く背景のキャンバス --- */
#background-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

/* --- ポートフォリオのメインコンテナ --- */
.portfolio-container {
    width: 80%;
    max-width: 900px;
    height: 500px;
    background: rgba(15, 20, 40, 0.5);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(0, 180, 255, 0.3);
    border-radius: 15px;
    display: flex;
    box-shadow: 0 0 25px rgba(0, 150, 255, 0.2);
    animation: fadeIn 1.5s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

/* --- 左側のナビゲーション --- */
.navigation {
    width: 200px;
    padding: 40px 20px;
    border-right: 1px solid rgba(0, 180, 255, 0.2);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.nav-link {
    color: #a0c0e0;
    text-decoration: none;
    padding: 15px 20px;
    margin: 5px 0;
    border-radius: 5px;
    transition: background-color 0.3s, color 0.3s;
    font-size: 16px;
}

.nav-link:hover {
    background-color: rgba(0, 180, 255, 0.1);
    color: #ffffff;
}

.nav-link.active {
    background-color: rgba(0, 180, 255, 0.2);
    color: #ffffff;
    font-weight: bold;
}

/* --- 右側のコンテンツエリア --- */
.content {
    flex-grow: 1;
    padding: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* --- ページコンテンツの基本スタイル --- */
.page-content {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    animation: fadeInPage 0.8s ease-in-out;
}

.page-content.active {
    display: flex;
}

@keyframes fadeInPage {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.page-content h2 {
    font-size: 32px;
    color: #00f0ff;
    margin-bottom: 20px;
}

.page-content p {
    font-size: 16px;
    line-height: 1.8;
    max-width: 450px;
    text-align: center;
}

.page-content ul {
    list-style: none;
    padding: 0;
    text-align: center;
}

.page-content li {
    font-size: 16px;
    margin: 8px 0;
}

/* --- パスワード画面のスタイル --- */
#password-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 100;
    display: flex;
    justify-content: center;
    align-items: center;
}

.password-box {
    text-align: center;
    background: rgba(15, 20, 40, 0.5);
    padding: 40px 50px;
    border: 1px solid rgba(0, 180, 255, 0.3);
    border-radius: 15px;
    box-shadow: 0 0 25px rgba(0, 150, 255, 0.2);
    width: 300px;
}

.password-box h2 {
    color: #00f0ff;
    margin-top: 0;
    margin-bottom: 25px;
    letter-spacing: 1px;
}

.welcome-text {
    color: #a0c0e0;
    margin-top: -15px;
    margin-bottom: 25px;
    font-size: 16px;
}

#password-input {
    width: 100%;
    padding: 12px;
    background-color: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(0, 180, 255, 0.2);
    border-radius: 5px;
    color: #e0e0e0;
    font-size: 16px;
    text-align: center;
    margin-bottom: 25px;
    box-sizing: border-box;
}

#submit-button {
    width: 100%;
    padding: 12px;
    background-color: rgba(0, 180, 255, 0.2);
    border: 1px solid rgba(0, 180, 255, 0.5);
    border-radius: 5px;
    color: #ffffff;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s;
}

#submit-button:hover {
    background-color: rgba(0, 180, 255, 0.4);
}

#error-message {
    color: #ff4d4d;
    font-size: 14px;
    margin-top: 15px;
    height: 20px;
    opacity: 0;
    transition: opacity 0.3s;
}

#error-message:not(.hidden) {
    opacity: 1;
}