/* リセット & ベース */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg: #0d1117;
    --bg-elevated: #161b22;
    --bg-card: #1c2128;
    --border: rgba(255, 255, 255, 0.08);
    --text: #e6edf3;
    --text-muted: #8b949e;
    --accent: #58a6ff;
    --accent-cyan: #39c5cf;
    --accent-soft: rgba(88, 166, 255, 0.15);
    --glow: rgba(88, 166, 255, 0.4);
    --font-sans: 'Outfit', 'Noto Sans JP', sans-serif;
    --font-jp: 'Noto Sans JP', 'Outfit', sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-jp);
    color: var(--text);
    line-height: 1.65;
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ヘッダー */
.header {
    background: rgba(13, 17, 23, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
    transition: box-shadow 0.3s ease;
}

.header.scrolled {
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-text {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    color: var(--text);
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-list a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.25s ease;
    position: relative;
}

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

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.25s ease;
}

.nav-list a:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    gap: 5px;
}

.mobile-menu-toggle span {
    width: 22px;
    height: 2px;
    background: var(--text-muted);
    transition: all 0.3s ease;
}

/* ヒーロー */
.hero {
    position: relative;
    padding: 160px 0;
    text-align: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: url('head.png') center/cover no-repeat;
}

.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(160deg, rgba(13, 17, 23, 0.75) 0%, rgba(13, 17, 23, 0.6) 50%, rgba(13, 17, 23, 0.85) 100%);
    pointer-events: none;
}

.hero-grid {
    position: absolute;
    inset: 0;
    z-index: 1;
    background-image:
        linear-gradient(rgba(88, 166, 255, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(88, 166, 255, 0.04) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 20%, transparent 70%);
    pointer-events: none;
}

.hero-glow {
    position: absolute;
    top: -30%;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    max-width: 600px;
    height: 300px;
    z-index: 1;
    background: radial-gradient(ellipse, rgba(88, 166, 255, 0.1) 0%, transparent 70%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-content {
    max-width: 720px;
    margin: 0 auto;
    animation: heroFade 1s ease forwards;
}

@keyframes heroFade {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero-label {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
}

.hero-title {
    font-family: var(--font-jp);
    font-size: clamp(2rem, 5vw, 3.25rem);
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 1rem;
    background: linear-gradient(180deg, #fff 0%, rgba(255,255,255,0.85) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.hero-description {
    font-size: 1rem;
    color: var(--text-muted);
    opacity: 0.9;
}

/* セクション */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--bg-elevated);
}

.section-label {
    font-family: var(--font-sans);
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent-cyan);
    margin-bottom: 0.5rem;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.25rem);
    font-weight: 700;
    color: var(--text);
    margin-bottom: 3rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 40px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), var(--accent-cyan));
    border-radius: 2px;
}

/* 会社概要 */
.about-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    max-width: 960px;
    margin: 0 auto;
}

.about-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.75rem;
    transition: border-color 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.about-item:hover {
    border-color: rgba(88, 166, 255, 0.25);
    transform: translateY(-2px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
}

.about-item h3 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.about-item p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.75;
}

/* 事業内容 */
.business-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
}

.business-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 2rem 1.5rem;
    text-align: center;
    transition: border-color 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.business-card:hover {
    border-color: rgba(88, 166, 255, 0.3);
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
}

.business-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1.25rem;
    color: var(--accent-cyan);
}

.business-icon svg {
    width: 100%;
    height: 100%;
}

.business-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.75rem;
}

.business-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* お問い合わせ */
.contact-content {
    max-width: 520px;
    margin: 0 auto;
    text-align: center;
}

.contact-info {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 2.5rem;
    transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.contact-info:hover {
    border-color: rgba(88, 166, 255, 0.2);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

.contact-info h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 1.25rem;
}

.contact-info p {
    color: var(--text-muted);
    line-height: 1.9;
    margin-bottom: 1rem;
}

.contact-note {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
}

/* フッター */
.footer {
    background: var(--bg-elevated);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
}

.footer-content p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 0.35rem;
}

.footer-address {
    font-size: 0.85rem;
    opacity: 0.8;
}

/* フェードイン用 */
.js-fade {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.55s ease, transform 0.55s ease;
}

.js-fade.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.about-content .js-fade:nth-child(1) { transition-delay: 0.05s; }
.about-content .js-fade:nth-child(2) { transition-delay: 0.1s; }
.about-content .js-fade:nth-child(3) { transition-delay: 0.15s; }
.about-content .js-fade:nth-child(4) { transition-delay: 0.2s; }
.about-content .js-fade:nth-child(5) { transition-delay: 0.25s; }
.about-content .js-fade:nth-child(6) { transition-delay: 0.3s; }
.business-grid .js-fade:nth-child(1) { transition-delay: 0.05s; }
.business-grid .js-fade:nth-child(2) { transition-delay: 0.12s; }
.business-grid .js-fade:nth-child(3) { transition-delay: 0.19s; }
.business-grid .js-fade:nth-child(4) { transition-delay: 0.26s; }

/* レスポンシブ */
@media (max-width: 768px) {
    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-elevated);
        border-bottom: 1px solid var(--border);
    }

    .nav.active {
        display: block;
    }

    .nav-list {
        flex-direction: column;
        padding: 1rem;
        gap: 0;
    }

    .nav-list li {
        border-bottom: 1px solid var(--border);
    }

    .nav-list a {
        display: block;
        padding: 1rem;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .hero {
        padding: 100px 0;
    }

    .section {
        padding: 70px 0;
    }

    .about-content,
    .business-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1.05rem;
    }

    .about-item,
    .business-card,
    .contact-info {
        padding: 1.5rem;
    }
}

a:focus,
button:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}