/* デザイン色彩設計: ライト/ダーク共通 */
:root {
    /* Base Colors (Light Theme) */
    --bg-color: #f8fafc;
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --accent-cyan: #0284c7;
    --accent-purple: #7e22ce;
    
    /* UI Elements */
    --glass-bg: rgba(255, 255, 255, 0.5);
    --glass-border: rgba(255, 255, 255, 0.3);
    --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.04);
    --nav-bg: rgba(255, 255, 255, 0.4);
    --nav-item-color: #475569;
    --nav-item-hover-bg: rgba(2, 132, 199, 0.06);
    --timeline-line: rgba(2, 132, 199, 0.15);
    --timeline-bg: #ffffff;
}

/* Dark Theme Overrides */
[data-theme='dark'] {
    --bg-color: #0b0f1a;
    --text-primary: #f1f5f9;
    --text-secondary: #e2e8f0;
    --text-muted: #94a3b8;
    --accent-cyan: #38bdf8;
    --accent-purple: #c084fc;
    
    --glass-bg: rgba(15, 23, 42, 0.5);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
    --nav-bg: rgba(15, 23, 42, 0.6);
    --nav-item-color: #cbd5e1;
    --nav-item-hover-bg: rgba(56, 189, 248, 0.1);
    --timeline-line: rgba(56, 189, 248, 0.2);
    --timeline-bg: #1e293b;
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    line-height: 1.7;
    color: var(--text-secondary);
    margin: 0;
    display: flex;
    background-color: var(--bg-color);
    position: relative;
    overflow-x: hidden;
    scroll-behavior: smooth;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* 背景: 静的なグラデーション */
.quantum-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
    background-color: var(--bg-color);
    background: radial-gradient(circle at 0% 0%, rgba(2, 132, 199, 0.06) 0%, transparent 50%),
                radial-gradient(circle at 100% 100%, rgba(126, 34, 206, 0.06) 0%, transparent 50%);
}

/* サイドバー: グラスモフィズム */
nav {
    width: 200px;
    height: 100vh;
    position: fixed;
    background: var(--nav-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-right: 1px solid var(--glass-border);
    padding: 2rem 1.25rem;
    overflow-y: auto;
    box-shadow: 10px 0 30px rgba(0, 0, 0, 0.02);
    z-index: 10;
    transition: background-color 0.4s ease, border-color 0.4s ease;
}

nav h1 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    background: linear-gradient(90deg, var(--accent-cyan), var(--text-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

nav p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
    font-weight: 400;
    line-height: 1.4;
}

nav ul {
    list-style: none;
    padding: 0;
    margin-bottom: 3rem;
}

nav ul li {
    margin-bottom: 0.8rem;
    position: relative;
}

nav ul li a {
    text-decoration: none;
    color: var(--nav-item-color);
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    border-radius: 8px;
    padding: 8px 12px;
    margin-left: -12px;
}

nav ul li a i {
    margin-right: 10px;
    width: 16px;
    text-align: center;
    color: var(--accent-cyan);
    opacity: 0.8;
    transition: all 0.3s ease;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--accent-cyan);
    background: var(--nav-item-hover-bg);
}

nav ul li a:hover i,
nav ul li a.active i {
    opacity: 1;
    transform: scale(1.1);
}

nav ul li a::before {
    content: "";
    position: absolute;
    left: -20px;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 0;
    background-color: var(--accent-cyan);
    transition: height 0.3s ease;
    border-radius: 0 4px 4px 0;
}

nav ul li a.active::before {
    height: 70%;
}

/* ナビ上部のボタン配置用 */
.nav-top-buttons {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    margin-bottom: 2rem;
    gap: 10px;
}

/* 言語スイッチ容器 */
.lang-switch-container {
    display: inline-flex;
    background: rgba(2, 132, 199, 0.1);
    border-radius: 20px;
    padding: 3px;
    position: relative;
    align-items: center;
    cursor: pointer;
    text-decoration: none !important;
    overflow: hidden;
    height: 32px;
}

/* スライドする「にゅるっと」した背景（ピル） */
.lang-switch-container::before {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: calc(50% - 3px);
    height: calc(100% - 6px);
    background: var(--timeline-bg);
    border-radius: 16px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.5s cubic-bezier(0.68, -0.6, 0.32, 1.6);
    z-index: 0;
}

/* ページごとのピル位置設定 */
.lang-jp::before { transform: translateX(0); }
.lang-en::before { transform: translateX(100%); }

/* ホバー時の「にゅるっと」した予兆アニメーション */
.lang-switch-container:hover::before {
    transform: scaleX(1.1);
}

.lang-jp:hover::before { transform: translateX(5%) scaleX(1.1); }
.lang-en:hover::before { transform: translateX(95%) scaleX(1.1); }

.lang-switch-btn {
    position: relative;
    z-index: 1;
    padding: 0 12px;
    font-size: 0.8rem;
    font-weight: 600;
    line-height: 26px;
    text-decoration: none !important;
    color: var(--text-muted) !important;
    border-radius: 16px;
    transition: color 0.4s ease;
    width: 48px;
    text-align: center;
}

.lang-switch-btn.active {
    color: var(--accent-cyan) !important;
    background: transparent !important; /* 背景は::beforeで表現 */
    box-shadow: none !important;
}

/* テーマ切り替えボタン */
#theme-toggle {
    background: rgba(2, 132, 199, 0.1);
    border: none;
    color: var(--accent-cyan);
    width: 34px;
    height: 34px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

#theme-toggle:hover {
    background: var(--accent-cyan);
    color: #fff;
    transform: rotate(20deg);
}

/* メインコンテンツ */
main {
    margin-left: 250px;
    padding: 4rem 5% 6rem 5%;
    max-width: 900px;
    position: relative;
    z-index: 1;
}

/* セクション: グラスモフィズム */
section {
    margin-bottom: 4rem;
    scroll-margin-top: 5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: var(--card-shadow);
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275), box-shadow 0.4s, background-color 0.4s, border-color 0.4s;
}

section:hover {
    transform: translateY(-5px);
    border-color: rgba(2, 132, 199, 0.3);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

h2 {
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 1rem;
    font-weight: 600;
    font-size: 1.5rem;
    color: var(--accent-cyan);
    letter-spacing: 0.05em;
    margin-top: 0;
    display: flex;
    align-items: center;
}

h2 i {
    margin-right: 12px;
    font-size: 1.3rem;
    opacity: 0.8;
}

.date {
    font-feature-settings: "tnum";
    color: var(--text-muted);
    flex-shrink: 0;
    width: 170px;
    margin-right: 15px;
    display: inline-block;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* リストスタイル */
.indent-list {
    list-style: none;
    padding-left: 0;
    margin-bottom: 1.5rem;
}

.indent-list li {
    position: relative;
    padding-left: 1.8rem;
    margin-bottom: 0.8rem;
    color: var(--text-secondary);
    display: flex;
    align-items: flex-start;
}

.indent-list.arrow-list li::before {
    content: "\f0da";
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    position: absolute;
    left: 0.2rem;
    top: 2px;
    color: var(--accent-cyan);
}

.number-list {
    list-style-type: none;
    counter-reset: my-counter;
    padding-left: 0;
}

.number-list li {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.number-list li::before {
    content: counter(my-counter) ".";
    counter-increment: my-counter;
    position: absolute;
    left: 0;
    top: 0;
    font-weight: 600;
    color: var(--accent-purple);
}

p {
    color: var(--text-secondary);
    font-weight: 400;
}

/* リンク装飾 */
main a:not(.portfolio-item a, .stealth-link) {
    color: var(--accent-cyan);
    text-decoration: none;
    position: relative;
    transition: color 0.3s;
    font-weight: 500;
}

main a:not(.portfolio-item a, .stealth-link)::after {
    content: '';
    position: absolute;
    width: 100%;
    transform: scaleX(0);
    height: 2px;
    bottom: -2px;
    left: 0;
    background-color: var(--accent-cyan);
    transform-origin: bottom right;
    transition: transform 0.3s ease-out;
    border-radius: 2px;
}

main a:not(.portfolio-item a, .stealth-link):hover::after {
    transform: scaleX(1);
    transform-origin: bottom left;
}

main a:not(.portfolio-item a, .stealth-link):hover {
    color: var(--accent-purple);
}

.stealth-link {
    color: inherit;
    text-decoration: underline dotted;
    text-decoration-color: var(--text-muted);
    text-underline-offset: 4px;
    transition: all 0.3s ease;
}

.stealth-link:hover {
    color: var(--accent-cyan);
    text-decoration-color: var(--accent-cyan);
}

/* 連絡先 */
.contact-list {
    list-style: none;
    padding: 0;
    margin-top: 1rem;
}

.contact-list li {
    margin-bottom: 0.8rem;
    display: flex;
    align-items: center;
}

.contact-list i {
    width: 25px;
    color: var(--accent-cyan);
    font-size: 1.1rem;
}

/* トップに戻るボタン */
#back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--accent-cyan);
    font-size: 1.2rem;
    text-decoration: none;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 100;
}

#back-to-top.show {
    opacity: 1;
    visibility: visible;
}

#back-to-top:hover {
    transform: translateY(-5px);
    background: var(--accent-cyan);
    color: #fff;
    box-shadow: 0 8px 32px rgba(2, 132, 199, 0.3);
}

/* ポートフォリオ */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.portfolio-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    backdrop-filter: blur(4px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.portfolio-item:hover {
    transform: scale(1.03);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
    border-color: var(--accent-cyan);
}

.portfolio-item img {
    width: 100%;
    display: block;
    cursor: pointer;
}

.portfolio-caption {
    display: none;
}

.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.lightbox.show {
    opacity: 1;
    visibility: visible;
}

.lightbox img {
    max-width: 90vw;
    max-height: 85vh;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    transform: scale(0.9);
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.lightbox.show img {
    transform: scale(1);
}

.lightbox-caption {
    position: absolute;
    bottom: 30px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
    padding: 8px 20px;
    border-radius: 30px;
    color: #fff;
    font-size: 0.9rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* ニュース・タイムライン */
.news-container {
    max-height: 400px;
    overflow-y: auto;
    padding-right: 15px;
    margin-top: 1rem;
}

.news-container::-webkit-scrollbar {
    width: 6px;
}

.news-container::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
}

.news-container::-webkit-scrollbar-thumb {
    background: var(--accent-cyan);
    opacity: 0.3;
    border-radius: 4px;
}

.timeline-list {
    list-style: none;
    padding: 10px 0 10px 10px;
    margin: 0;
    position: relative;
}

.timeline-list::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 55px;
    width: 2px;
    background-color: var(--timeline-line);
}

.timeline-list li {
    position: relative;
    padding-left: 115px;
    margin-bottom: 2rem;
    color: var(--text-secondary);
    transition: transform 0.3s;
}

.timeline-list li:hover {
    transform: translateX(5px);
}

.timeline-list .date {
    position: absolute;
    left: 10px;
    top: -2px;
    width: 90px;
    background: var(--timeline-bg);
    border: 2px solid var(--accent-cyan);
    border-radius: 20px;
    color: var(--accent-cyan);
    font-size: 0.8rem;
    font-weight: 700;
    text-align: center;
    padding: 3px 0;
    z-index: 1;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

/* レスポンシブ */
@media (max-width: 850px) {
    body {
        flex-direction: column;
    }

    nav {
        width: 100%;
        height: auto;
        position: static;
        border-right: none;
        border-bottom: 1px solid var(--glass-border);
        padding: 1.2rem 1.2rem;
        background: var(--nav-bg);
    }

    .nav-top-buttons {
        margin-bottom: 1.2rem;
    }

    .lang-switch-btn {
        padding: 4px 12px;
        font-size: 0.8rem;
    }

    #theme-toggle {
        width: 36px;
        height: 36px;
    }

    nav h1 {
        font-size: 1.1rem;
        margin-top: 0.5rem;
    }

    nav ul {
        display: flex;
        flex-wrap: wrap;
        gap: 0.5rem;
        margin-bottom: 1rem;
        padding-top: 0.5rem;
    }

    nav ul li {
        margin: 0;
    }

    nav ul li a::before {
        display: none;
    }

    main {
        margin-left: 0;
        padding: 2rem 1.2rem;
        width: 100%;
        box-sizing: border-box;
    }

    section {
        padding: 1.5rem;
        border-radius: 16px;
    }

    .date {
        width: auto;
        margin-bottom: 5px;
    }

    .timeline-list li {
        padding-left: 0;
        padding-top: 35px;
    }

    .timeline-list::before {
        left: 20px;
    }

    .timeline-list .date {
        left: 0;
    }
}