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

:root {
    --bg: #0a0f1e;
    --accent: #6CB4EE;
    --accent-glow: rgba(108, 180, 238, 0.25);
    --accent-deep: rgba(108, 180, 238, 0.08);
    --text-primary: rgba(255, 255, 255, 0.88);
    --text-secondary: rgba(255, 255, 255, 0.55);
    --text-body: rgba(255, 255, 255, 0.72);
    --panel-bg: rgba(255, 255, 255, 0.03); /* deeper glass */
    --panel-border: rgba(255, 255, 255, 0.08); /* softer base border */
    --font: 'Zen Kurenaido', sans-serif;
    --font-body: 'Noto Serif JP', '游明朝', 'Yu Mincho', serif;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.9;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ─── Canvas Rain ─── */
#rain-canvas {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    opacity: 0.6;
}

/* ─── Page Container ─── */
.page {
    position: relative;
    z-index: 1;
}

/* ─── Hero Section ─── */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 100px 24px 60px;
    overflow: hidden;
    background: radial-gradient(ellipse at center, rgba(108, 180, 238, 0.08) 0%, transparent 70%);
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url('../image/back.jpg') center/cover no-repeat;
    filter: brightness(0.35) saturate(0.7);
    z-index: -2;
}

.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg,
            rgba(10, 15, 30, 0.3) 0%,
            rgba(10, 15, 30, 0.6) 60%,
            rgba(10, 15, 30, 1) 100%);
    z-index: -1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 20px;
    border: 1px solid rgba(108, 180, 238, 0.3);
    border-radius: 24px;
    background: rgba(108, 180, 238, 0.08);
    box-shadow: 0 0 20px rgba(108, 180, 238, 0.1);
    color: var(--accent);
    font-size: 0.8rem;
    letter-spacing: 0.1em;
    margin-bottom: 32px;
    animation: fadeInDown 1s ease-out 0.2s both;
}

.hero-badge svg {
    width: 14px;
    height: 14px;
}

.hero h1 {
    font-size: 2.2rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    line-height: 1.6;
    margin-bottom: 24px;
    text-shadow: 0 0 50px rgba(108, 180, 238, 0.4), 0 4px 16px rgba(0, 0, 0, 0.8);
    animation: fadeInDown 1s ease-out 0.4s both;
}

.hero h1 .brand {
    display: block;
    font-size: 3.4rem;
    letter-spacing: 0.35em;
    margin-bottom: 12px;
}

.hero h1 .tagline {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.85);
    letter-spacing: 0.15em;
    font-weight: 400;
}

.hero-description {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.95rem;
    color: var(--text-body);
    max-width: 560px;
    margin: 0 auto 40px;
    line-height: 2.2;
    animation: fadeInDown 1s ease-out 0.6s both;
}

.hero-cta {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 18px 48px;
    border: 2px solid var(--accent);
    border-radius: 36px;
    background: rgba(108, 180, 238, 0.12);
    color: var(--accent);
    text-decoration: none;
    font-family: var(--font);
    font-size: 1.05rem;
    letter-spacing: 0.15em;
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: 0 0 40px rgba(108, 180, 238, 0.15);
    animation: fadeInUp 1s ease-out 0.8s both;
}

.hero-cta svg {
    width: 20px;
    height: 20px;
    transition: transform 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

@media (hover: hover) {
    .hero-cta:hover {
        background: rgba(108, 180, 238, 0.25);
        box-shadow: 0 0 60px rgba(108, 180, 238, 0.4);
        transform: translateY(-3px);
    }

    .hero-cta:hover svg {
        transform: translateX(4px);
    }
}

.hero-sub {
    margin-top: 20px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    letter-spacing: 0.08em;
    animation: fadeInUp 1s ease-out 1s both;
}



/* ─── Section Common ─── */
.section {
    max-width: 860px;
    margin: 0 auto;
    padding: 100px 24px;
}

.section-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.75rem;
    color: var(--accent);
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 16px;
    opacity: 0.9;
}

.section-label svg {
    width: 16px;
    height: 16px;
}

.section h2 {
    font-size: 1.65rem;
    font-weight: 400;
    letter-spacing: 0.15em;
    margin-bottom: 20px;
    border: none;
    padding: 0;
    color: var(--text-primary);
}

.section-lead {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.92rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 640px;
    line-height: 2.1;
    margin-bottom: 48px;
}

/* ─── Feature Grid ─── */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--panel-bg);
    border: 1px solid var(--panel-border);
    border-radius: 20px;
    padding: 32px 28px;
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 4px 24px rgba(0, 0, 0, 0.2);
}

@media (hover: hover) {
    .feature-card:hover {
        border-color: rgba(108, 180, 238, 0.3);
        background: rgba(255, 255, 255, 0.05);
        transform: translateY(-6px);
        box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1), 0 12px 40px rgba(0, 0, 0, 0.3), 0 0 20px rgba(108, 180, 238, 0.1);
    }
}

.feature-card-icon {
    width: 54px;
    height: 54px;
    border-radius: 16px;
    background: rgba(108, 180, 238, 0.12);
    border: 1px solid rgba(108, 180, 238, 0.25);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    margin-bottom: 22px;
}

.feature-card-icon svg {
    width: 24px;
    height: 24px;
}

.feature-card h3 {
    font-size: 1.05rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.85rem;
    color: var(--text-body);
    line-height: 1.9;
    margin: 0;
}

.feature-card-wide {
    grid-column: 1 / -1;
}

/* ─── Sound List Section ─── */
.sound-section {
    background: linear-gradient(180deg,
            rgba(108, 180, 238, 0.03) 0%,
            transparent 100%);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.sound-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.sound-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
    background: var(--panel-bg);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    transition: all 0.3s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

@media (hover: hover) {
    .sound-item:hover {
        border-color: rgba(108, 180, 238, 0.3);
        background: rgba(108, 180, 238, 0.06);
        transform: translateY(-3px);
        box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1), 0 8px 24px rgba(0, 0, 0, 0.25);
    }
}

.sound-item-icon {
    width: 44px;
    height: 44px;
    min-width: 44px;
    border-radius: 50%;
    background: rgba(108, 180, 238, 0.12);
    border: 1px solid rgba(108, 180, 238, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}

.sound-item-icon svg {
    width: 20px;
    height: 20px;
}

.sound-item-info {
    flex: 1;
}

.sound-item-name {
    font-size: 0.95rem;
    letter-spacing: 0.08em;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.3;
}

.sound-item-desc {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 2px;
    line-height: 1.4;
}

/* ─── Screenshot / Image Placeholder ─── */
.screenshot-area {
    margin: 40px auto;
    max-width: 500px;
    aspect-ratio: 9/16;
    border-radius: 20px;
    border: 1px dashed rgba(108, 180, 238, 0.3);
    background: rgba(108, 180, 238, 0.04);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 0.78rem;
    letter-spacing: 0.06em;
}

.screenshot-area svg {
    width: 32px;
    height: 32px;
    color: rgba(108, 180, 238, 0.4);
}

.screenshot-area-wide {
    aspect-ratio: 16/9;
    max-width: 720px;
    border-radius: 24px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.08); /* More like a glass container */
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

.screenshot-area img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* ─── Use Case Section ─── */
.usecase-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.usecase-item {
    padding: 28px 24px;
    background: var(--panel-bg);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 4px 16px rgba(0, 0, 0, 0.15);
}

@media (hover: hover) {
    .usecase-item:hover {
        border-color: rgba(108, 180, 238, 0.3);
        transform: translateY(-4px);
        box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1), 0 10px 30px rgba(0, 0, 0, 0.25);
    }
}

.usecase-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    border-radius: 14px;
    background: rgba(108, 180, 238, 0.12);
    border: 1px solid rgba(108, 180, 238, 0.25);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}

.usecase-icon svg {
    width: 22px;
    height: 22px;
}

.usecase-item h3 {
    font-size: 0.95rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.usecase-item p {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.82rem;
    color: var(--text-body);
    line-height: 1.8;
    margin: 0;
}

/* ─── Device Note ─── */
.device-note {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 24px 28px;
    background: rgba(108, 180, 238, 0.05);
    border: 1px solid rgba(108, 180, 238, 0.15);
    border-radius: 16px;
    margin-top: 40px;
}

.device-note-icon {
    width: 40px;
    height: 40px;
    min-width: 40px;
    border-radius: 12px;
    background: rgba(108, 180, 238, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    margin-top: 2px;
}

.device-note-icon svg {
    width: 20px;
    height: 20px;
}

.device-note p {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.9;
    margin: 0;
}

.device-note strong {
    color: rgba(255, 255, 255, 0.95);
    font-weight: 400;
}


/* ─── FAQ Section ─── */
.faq-item {
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 24px 0;
}

.faq-item:first-child {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.faq-q {
    font-size: 1rem;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: rgba(255, 255, 255, 0.95);
}

.faq-q .q-mark {
    color: var(--accent);
    font-size: 0.9rem;
    flex-shrink: 0;
    margin-top: 2px;
}

.faq-a {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.85rem;
    color: var(--text-body);
    line-height: 1.9;
    padding-left: 28px;
    margin: 0;
}

/* ─── CTA Section ─── */
.cta-section {
    text-align: center;
    padding: 120px 24px;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center,
            rgba(108, 180, 238, 0.1) 0%,
            transparent 70%);
    pointer-events: none;
}

.cta-section h2 {
    font-size: 1.8rem;
    font-weight: 400;
    letter-spacing: 0.25em;
    margin-bottom: 20px;
    border: none;
    padding: 0;
    color: var(--text-primary);
    text-shadow: 0 0 40px rgba(108, 180, 238, 0.3);
}

.cta-section .cta-lead {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: 0.95rem;
    color: var(--text-body);
    margin-bottom: 40px;
    line-height: 2.2;
}

.cta-btn {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 20px 54px;
    border: 2px solid var(--accent);
    border-radius: 40px;
    background: rgba(108, 180, 238, 0.15);
    color: var(--accent);
    text-decoration: none;
    font-family: var(--font);
    font-size: 1.1rem;
    letter-spacing: 0.15em;
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    box-shadow: 0 0 40px rgba(108, 180, 238, 0.2);
}

.cta-btn svg {
    width: 22px;
    height: 22px;
    transition: transform 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

@media (hover: hover) {
    .cta-btn:hover {
        background: rgba(108, 180, 238, 0.25);
        box-shadow: 0 0 70px rgba(108, 180, 238, 0.4);
        transform: translateY(-4px);
    }

    .cta-btn:hover svg {
        transform: translateX(4px);
    }
}

/* ─── Footer ─── */
.page-footer {
    padding: 40px 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.page-footer a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

@media (hover: hover) {
    .page-footer a:hover {
        color: var(--accent);
    }
}

.footer-links {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 8px;
}

/* ─── Animations ─── */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ─── Scroll Reveal ─── */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1s cubic-bezier(0.165, 0.84, 0.44, 1), transform 1s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ─── Divider ─── */
.section-divider {
    max-width: 860px;
    margin: 0 auto;
    height: 1px;
    background: radial-gradient(circle, rgba(108, 180, 238, 0.4) 0%, transparent 80%);
    box-shadow: 0 0 15px rgba(108, 180, 238, 0.2);
    border: none;
}

/* ─── Tablet ─── */
@media (max-width: 768px) {
    .usecase-list {
        grid-template-columns: 1fr;
        gap: 16px;
    }
}

/* ─── Mobile ─── */
@media (max-width: 480px) {
    .page {
        overflow-x: hidden;
    }

    .section {
        padding: 60px 16px;
    }

    .section-divider {
        width: calc(100% - 32px);
        margin: 0 auto;
    }

    /* ─ Hero ─ */
    .hero {
        padding: 80px 20px 60px;
    }

    .hero h1 .brand {
        font-size: 2.2rem;
        letter-spacing: 0.2em;
    }

    .hero h1 .tagline {
        font-size: 0.88rem;
    }

    .hero-description {
        font-size: 0.82rem;
        line-height: 2;
    }

    .hero-cta {
        padding: 16px 28px;
        font-size: 0.92rem;
        max-width: 100%;
    }

    .hero-sub {
        font-size: 0.7rem;
    }

    /* ─ Sections ─ */
    .section h2 {
        font-size: 1.3rem;
        letter-spacing: 0.1em;
    }

    .section-lead {
        font-size: 0.85rem;
        line-height: 2;
        margin-bottom: 32px;
    }

    /* ─ Feature Grid ─ */
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .feature-card {
        padding: 24px 20px;
    }

    /* ─ Sound Grid ─ */
    .sound-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .sound-item {
        padding: 16px 18px;
        gap: 14px;
    }

    .sound-item-icon {
        width: 40px;
        height: 40px;
        min-width: 40px;
    }

    .sound-item-icon svg {
        width: 18px;
        height: 18px;
    }

    /* ─ Screenshot ─ */
    .screenshot-area {
        max-width: 100%;
    }

    .screenshot-area-wide {
        max-width: 100%;
        border-radius: 16px;
    }

    /* ─ Use Case ─ */
    .usecase-list {
        grid-template-columns: 1fr;
        gap: 14px;
    }

    .usecase-item {
        padding: 24px 20px;
    }

    .usecase-item p {
        font-size: 0.8rem;
        text-align: left;
    }

    /* ─ Device Note ─ */
    .device-note {
        padding: 18px 16px;
        gap: 12px;
        margin-top: 28px;
    }

    .device-note-icon {
        width: 36px;
        height: 36px;
        min-width: 36px;
    }

    .device-note p {
        font-size: 0.8rem;
        line-height: 1.8;
    }

    /* ─ FAQ ─ */
    .faq-q {
        font-size: 0.92rem;
        gap: 8px;
    }

    .faq-a {
        font-size: 0.8rem;
        padding-left: 22px;
    }

    /* ─ CTA ─ */
    .cta-section {
        padding: 80px 20px;
    }

    .cta-section h2 {
        font-size: 1.35rem;
        letter-spacing: 0.15em;
    }

    .cta-btn {
        padding: 16px 32px;
        font-size: 0.95rem;
    }

    /* ─ Footer ─ */
    .footer-links {
        gap: 8px;
        font-size: 0.7rem;
    }
}

@media (max-width: 360px) {
    .hero h1 .brand {
        font-size: 1.9rem;
    }

    .hero-cta {
        padding: 14px 24px;
        font-size: 0.88rem;
    }

    .section h2 {
        font-size: 1.15rem;
    }
}