:root {
    --background: #03040a;
    --surface: rgba(255, 255, 255, 0.06);
    --surface-strong: rgba(255, 255, 255, 0.1);
    --text: #ffffff;
    --muted: rgba(255, 255, 255, 0.66);
    --cyan: #00c8ff;
    --blue: #247cff;
    --pink: #ff2e8b;
    --purple: #bd32e8;
    --border: rgba(255, 255, 255, 0.12);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--text);
    background:
        radial-gradient(
            circle at 50% 10%,
            rgba(21, 41, 114, 0.2),
            transparent 35%
        ),
        var(--background);
    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Helvetica Neue",
        "Hiragino Sans",
        "Yu Gothic",
        sans-serif;
    line-height: 1.7;
}

a {
    color: inherit;
    text-decoration: none;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 72px;
    padding: 0 6vw;
    background: rgba(3, 4, 10, 0.78);
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    backdrop-filter: blur(20px);
}

.brand,
.footer-brand {
    font-size: 24px;
    font-weight: 900;
    letter-spacing: 0.08em;
    background: linear-gradient(
        90deg,
        var(--cyan),
        var(--blue),
        var(--pink)
    );
    -webkit-background-clip: text;
    color: transparent;
}

.nav {
    display: flex;
    gap: 24px;
    font-size: 14px;
    color: var(--muted);
}

.nav a:hover,
.footer-links a:hover {
    color: var(--cyan);
}

.hero {
    position: relative;
    min-height: calc(100vh - 72px);
    display: grid;
    place-items: center;
    overflow: hidden;
    padding: 72px 24px;
}

.hero-content {
    position: relative;
    z-index: 2;
    width: min(760px, 100%);
    text-align: center;
}

.app-icon {
    width: 154px;
    height: 154px;
    object-fit: cover;
    border-radius: 34px;
    box-shadow:
        0 0 30px rgba(0, 200, 255, 0.28),
        0 0 70px rgba(255, 46, 139, 0.18);
}

.eyebrow {
    margin: 28px 0 10px;
    color: var(--cyan);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 0.18em;
}

h1 {
    margin: 0;
    font-size: clamp(44px, 8vw, 82px);
    line-height: 1.08;
    letter-spacing: -0.04em;
}

h1 span,
.section-heading h2 span {
    background: linear-gradient(
        90deg,
        var(--cyan),
        var(--blue),
        var(--pink)
    );
    -webkit-background-clip: text;
    color: transparent;
}

.hero-description {
    margin: 28px auto 0;
    max-width: 650px;
    color: var(--muted);
    font-size: clamp(16px, 2vw, 19px);
}

.hero-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 34px;
}

.store-button,
.secondary-button {
    min-width: 210px;
    padding: 15px 22px;
    border-radius: 16px;
    font-weight: 800;
}

.store-button {
    background: linear-gradient(
        90deg,
        var(--cyan),
        var(--blue),
        var(--pink)
    );
    box-shadow: 0 12px 40px rgba(36, 124, 255, 0.25);
}

.store-button.disabled {
    opacity: 0.8;
    cursor: default;
}

.secondary-button {
    background: var(--surface);
    border: 1px solid var(--border);
}

.secondary-button:hover {
    background: var(--surface-strong);
}

.hero-glow {
    position: absolute;
    width: 420px;
    height: 420px;
    border-radius: 50%;
    filter: blur(90px);
    opacity: 0.2;
}

.hero-glow-blue {
    left: -180px;
    top: 10%;
    background: var(--cyan);
}

.hero-glow-pink {
    right: -180px;
    bottom: 5%;
    background: var(--pink);
}

.section {
    width: min(1120px, calc(100% - 40px));
    margin: 0 auto;
    padding: 110px 0;
}

.section-heading {
    text-align: center;
    margin-bottom: 44px;
}

.section-heading h2,
.concept-card h2 {
    margin: 0;
    font-size: clamp(32px, 5vw, 50px);
    line-height: 1.25;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.feature-card,
.concept-card,
.legal-card {
    background: linear-gradient(
        145deg,
        rgba(255, 255, 255, 0.08),
        rgba(255, 255, 255, 0.025)
    );
    border: 1px solid var(--border);
    box-shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
}

.feature-card {
    min-height: 270px;
    padding: 30px;
    border-radius: 28px;
}

.feature-icon {
    font-size: 38px;
}

.feature-card h3 {
    margin: 18px 0 8px;
    font-size: 21px;
}

.feature-card p,
.concept-card p {
    margin: 0;
    color: var(--muted);
}

.concept-section {
    width: min(900px, calc(100% - 40px));
    margin: 0 auto;
    padding: 20px 0 120px;
}

.concept-card {
    padding: clamp(34px, 7vw, 72px);
    border-radius: 34px;
    text-align: center;
}

.concept-card p:last-child {
    margin-top: 24px;
}

.site-footer {
    padding: 50px 24px;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 22px;
    margin: 22px 0;
    color: var(--muted);
    font-size: 14px;
}

.copyright {
    margin: 0;
    color: rgba(255, 255, 255, 0.38);
    font-size: 12px;
}

/* 規約・プライバシー・サポートページ */

.legal-page {
    width: min(880px, calc(100% - 32px));
    margin: 0 auto;
    padding: 70px 0 120px;
}

.legal-card {
    padding: clamp(26px, 6vw, 56px);
    border-radius: 30px;
}

.legal-card h1 {
    margin-bottom: 8px;
    font-size: clamp(34px, 6vw, 54px);
}

.updated-date {
    margin-bottom: 42px;
    color: var(--muted);
    font-size: 14px;
}

.legal-card h2 {
    margin-top: 42px;
    font-size: 21px;
}

.legal-card p,
.legal-card li {
    color: rgba(255, 255, 255, 0.74);
}

.legal-card ul {
    padding-left: 22px;
}

.contact-box {
    margin-top: 28px;
    padding: 22px;
    background: rgba(255, 255, 255, 0.055);
    border-radius: 18px;
    border: 1px solid var(--border);
}

@media (max-width: 760px) {
    .site-header {
        padding: 0 20px;
    }

    .nav {
        gap: 12px;
        font-size: 12px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding-top: 50px;
    }

    .app-icon {
        width: 126px;
        height: 126px;
        border-radius: 28px;
    }

    .hero-description br {
        display: none;
    }
}

@media (max-width: 520px) {
    .nav a:first-child {
        display: none;
    }

    .hero-actions {
        flex-direction: column;
    }

    .store-button,
    .secondary-button {
        width: 100%;
    }
}