:root {
    --bg: #f5f7fb;
    --bg-alt: #ffffff;
    --text: #1f2a37;
    --muted: #5f6b7c;
    --accent: #0084ff;
    --accent-soft: rgba(0, 132, 255, 0.12);
    --border: #e2e8f0;
    --card-shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
    --radius-lg: 20px;
    --radius-md: 14px;
    --radius-sm: 8px;
    font-family: 'Segoe UI', 'Hiragino Sans', 'Meiryo', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--accent);
    text-decoration: none;
}

ul {
    list-style: none;
}

/* Layout */
.site-header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 50;
}

.site-header.is-active {
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.15);
}

.site-header nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

.brand {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text);
}

.nav-links {
    display: flex;
    gap: 18px;
    align-items: center;
}

.nav-links a {
    font-weight: 600;
    color: var(--muted);
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    transition: background 0.2s ease, color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus {
    background: var(--accent-soft);
    color: var(--accent);
}

.nav-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: #fff;
    align-items: center;
    justify-content: center;
    gap: 6px;
    flex-direction: column;
    cursor: pointer;
    transition: box-shadow 0.2s ease;
}

.nav-toggle span {
    width: 20px;
    height: 2px;
    background: var(--text);
    border-radius: 999px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.is-open span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 24px;
}

.hero {
    padding: 64px 24px;
    text-align: center;
    background: radial-gradient(circle at top, rgba(0, 132, 255, 0.12), transparent 60%), var(--bg);
    border-bottom: 1px solid var(--border);
}

.hero h1 {
    font-size: clamp(2.2rem, 4vw, 3rem);
    margin-bottom: 18px;
}

.hero p {
    color: var(--muted);
    max-width: 720px;
    margin: 0 auto;
}

.hero-actions {
    margin-top: 28px;
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: 1px solid transparent;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 10px 20px rgba(0, 132, 255, 0.25);
}

.btn-secondary {
    background: #eef3ff;
    border-color: #bcd3ff;
    color: #0f172a;
    box-shadow: 0 10px 20px rgba(0, 132, 255, 0.15);
}

.btn-secondary:hover,
.btn-secondary:focus {
    background: #dbe7ff;
    border-color: #7eb0ff;
    color: #0f172a;
}

.btn:hover {
    transform: translateY(-2px);
}

.section-title {
    font-size: 1.8rem;
    margin-bottom: 30px;
}

.section-subtitle {
    color: var(--muted);
    margin-bottom: 45px;
}

.card-grid {
    display: grid;
    /* 4列固定（幅が足りない場合は自動で折り返す） */
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 24px;
}

.card {
    background: var(--bg-alt);
    padding: 24px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.card[data-scroll-target] {
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card[data-scroll-target]:hover,
.card[data-scroll-target]:focus {
    transform: translateY(-4px);
    box-shadow: 0 14px 30px rgba(15, 23, 42, 0.15);
}

.card h3 {
    font-size: 1.2rem;
}

.card p {
    color: var(--muted);
    flex-grow: 1;
}

.category-tag {
    display: inline-flex;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
}

.developer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.developer-card {
    background: var(--bg-alt);
    padding: 24px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--card-shadow);
    display: flex;
    gap: 18px;
}

.developer-card img {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    border: 2px solid var(--border);
}

.developer-role {
    font-weight: 600;
    color: var(--accent);
    margin-top: 2px;
}

.developer-bio {
    color: var(--muted);
    font-size: 0.95rem;
    margin-top: 8px;
}

.info-banner {
    margin-top: 40px;
    padding: 24px;
    border-radius: var(--radius-lg);
    border: 1px dashed var(--border);
    background: var(--bg-alt);
    color: var(--muted);
}

.timeline {
    border-left: 2px solid var(--border);
    margin-left: 12px;
    padding-left: 32px;
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.timeline-item {
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid var(--accent);
    background: #fff;
    left: -39px;
    top: 6px;
}

.timeline-date {
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 8px;
}

.timeline-card {
    background: var(--bg-alt);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    padding: 20px;
    box-shadow: var(--card-shadow);
}

.status-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: 8px;
}

.status-success { background: rgba(0, 201, 142, 0.15); color: #00a66c; }
.status-progress { background: rgba(255, 178, 0, 0.2); color: #c17900; }
.status-problem { background: rgba(255, 76, 97, 0.2); color: #cf2a39; }

.list-columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}

.list-card {
    background: var(--bg-alt);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    padding: 20px;
}

.download-card {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    box-shadow: var(--card-shadow);
}

.download-meta {
    font-size: 0.9rem;
    color: var(--muted);
}

.thumb {
    width: 100%;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    background: #fff;
    box-shadow: var(--card-shadow);
}

.footer {
    border-top: 1px solid var(--border);
    padding: 32px 24px;
    text-align: center;
    color: var(--muted);
}

.footer nav {
    margin-bottom: 8px;
}

.footer nav a {
    margin: 0 12px;
    color: var(--muted);
}

.footer nav a:hover {
    color: var(--accent);
}

.pill-list {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 12px;
}

.pill {
    padding: 4px 12px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--bg);
    font-size: 0.85rem;
    color: var(--muted);
}

.grid-two {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.muted-box {
    padding: 24px;
    border-radius: var(--radius-lg);
    background: var(--accent-soft);
    color: var(--text);
}

.download-modal {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.download-modal.is-open {
    display: flex;
}

.download-modal__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(8px);
}

.download-modal__body {
    position: relative;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: 0 30px 80px rgba(15, 23, 42, 0.3);
    padding: 24px 32px;
    width: 820px;
    max-width: 95%;
    min-height: 360px;
    z-index: 1;
}

.download-modal__close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--muted);
}

.download-modal__content {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 28px;
    align-items: stretch;
    min-height: 240px;
}

.download-modal__thumb-block {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.download-modal__thumb-block img {
    width: 100%;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    box-shadow: var(--card-shadow);
    object-fit: cover;
    height: 240px;
}

.download-modal__title {
    font-weight: 700;
    font-size: 1.1rem;
    margin: 0;
    color: var(--text);
}

.download-modal__details {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 240px;
}

.download-modal__description {
    font-size: 1rem;
    color: var(--text);
    margin: 0 0 16px 0;
}

.modal-checkbox {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    color: var(--text);
}

.modal-checkbox input {
    width: 18px;
    height: 18px;
}

.modal-checkbox a {
    color: var(--accent);
}

.download-list {
    margin-top: 16px;
    border-top: 1px solid var(--border);
}

.download-list__item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}

.download-list__info {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.download-list__name {
    font-weight: 600;
    color: var(--text);
}

.download-list__meta {
    font-size: 0.9rem;
    color: var(--muted);
}

.download-list__button[disabled] {
    opacity: 0.5;
    cursor: not-allowed;
}

body.modal-open {
    overflow: hidden;
}

@media (max-width: 900px) {
    .download-modal__content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 720px) {
    .nav-toggle {
        display: inline-flex;
    }
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        gap: 12px;
        padding: 16px 24px 24px;
        background: rgba(255, 255, 255, 0.98);
        border-bottom: 1px solid var(--border);
        box-shadow: 0 25px 35px rgba(15, 23, 42, 0.08);
        transform-origin: top;
        transform: translateY(-10px);
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.25s ease, transform 0.25s ease;
    }
    .nav-links.is-open {
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto;
    }
    .developer-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    .timeline {
        margin-left: 0;
        padding-left: 20px;
    }
}