/* ===== Brand Tokens (from app-inc.com) ===== */
:root {
    --color-bg: #FCFCFA;
    --color-dark: #282C1F;
    --color-yellow: #D2FF00;
    --color-beige: #F4F4ED;
    --color-green: #A7B54D;
    --color-gray: #6B6B6B;
    --color-light-gray: #E5E5E0;

    --font-zen: 'Zen Kaku Gothic New', sans-serif;
    --font-smooch: 'Smooch', cursive;

    --container-max: 1080px;
    --header-height: 72px;
    --radius: 12px;
    --radius-sm: 8px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-zen);
    background: var(--color-bg);
    color: var(--color-dark);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    line-height: 1.7;
}

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

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

/* ===== Container ===== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header ===== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-yellow);
    border-bottom: none;
    transition: transform 0.3s ease;
}

.header-inner {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-logo-img {
    height: 24px;
    width: auto;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-nav a {
    padding: 8px 16px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: background 0.2s ease;
}

.header-nav a:hover {
    background: rgba(210, 255, 0, 0.15);
}

.header-nav .nav-cta {
    background: var(--color-dark);
    color: #fff;
    margin-left: 8px;
}

.header-nav .nav-cta:hover {
    background: #3a3f2e;
}

.header-spacer {
    height: var(--header-height);
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.menu-toggle span {
    width: 20px;
    height: 2px;
    background: var(--color-dark);
    border-radius: 1px;
    transition: 0.3s ease;
}

.mobile-menu {
    background: var(--color-dark);
    padding: 16px 24px 24px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.mobile-menu.hidden {
    display: none;
}

.mobile-menu a {
    color: #fff;
    padding: 12px 16px;
    font-size: 16px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: background 0.2s ease;
}

.mobile-menu a:hover {
    background: rgba(255, 255, 255, 0.1);
}

.mobile-menu .nav-cta {
    background: var(--color-yellow);
    color: var(--color-dark);
    text-align: center;
    font-weight: 700;
    margin-top: 8px;
}

/* ===== Section common ===== */
section {
    padding: 100px 0;
    scroll-margin-top: calc(var(--header-height) + 20px);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-label {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-green);
    margin-bottom: 12px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.3;
}

/* ===== Hero ===== */
.hero {
    padding: 80px 0 100px;
    background: var(--color-bg);
    position: relative;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: left center / cover no-repeat;
    opacity: 0;
    transition: opacity 1.5s ease-in-out;
    z-index: 0;
}
.hero-bg.active { opacity: 1; }
.hero-bg-1 { background-image: url('../assets/hero-1.jpg'); }
.hero-bg-2 { background-image: url('../assets/hero-2.jpg'); }
.hero-bg-3 { background-image: url('../assets/hero-3.jpg'); }
.hero-bg-4 { background-image: url('../assets/hero-4.jpg'); }

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

.hero-content {
    display: flex;
    align-items: flex-start;
    gap: 60px;
}

.hero-text {
    flex: 1;
}

.hero-label {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-green);
    margin-bottom: 20px;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.03em;
    margin-bottom: 24px;
    color: #fff;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-weight: 700;
    line-height: 1.5;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 36px;
    font-size: 26px;
    text-shadow: 0 2px 6px rgba(0,0,0,0.25);
}

.hero-visual {
    flex: 0 0 320px;
}

.hero-visual-mobile {
    display: none;
}

.hero-phone-mockup {
    position: relative;
}

.phone-mask {
    width: 280px;
    height: 607px;
    border-radius: 40px;
    overflow: hidden;
    margin: 0 auto;
    position: relative;
    box-shadow:
        0 0 0 6px #1a1a1a,
        0 0 0 8px #333,
        0 20px 60px rgba(0, 0, 0, 0.2),
        0 4px 16px rgba(0, 0, 0, 0.1);
}

.phone-mask img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
}

.hero-screen {
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 1.5s ease-in-out;
}
.hero-screen.active { opacity: 1; }

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 28px;
    font-family: var(--font-zen);
    font-size: 15px;
    font-weight: 700;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--color-dark);
    color: #fff;
}

.btn-primary:hover {
    background: #3a3f2e;
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.btn-large {
    padding: 18px 36px;
    font-size: 17px;
}

.icon-apple {
    flex-shrink: 0;
}

/* ===== Empathy (共感) ===== */
.empathy {
    background: var(--color-beige);
}

.empathy-checklist {
    list-style: none;
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 0;
}

.empathy-checklist li {
    font-size: 17px;
    line-height: 1.6;
    padding: 18px 0 18px 44px;
    position: relative;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.empathy-checklist li:last-child {
    border-bottom: none;
}

.empathy-checklist .checkbox {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 22px;
    height: 22px;
    border: 2px solid rgba(0, 0, 0, 0.25);
    border-radius: 5px;
}

.empathy-conclusion {
    text-align: center;
    font-size: 28px;
    font-weight: 500;
    margin-top: 48px;
    line-height: 1.6;
}

.empathy-conclusion strong {
    color: var(--color-dark);
    font-weight: 700;
}

/* ===== Insight (問題の本質) ===== */
.insight {
    background: var(--color-dark);
    text-align: center;
}

.insight-content {
    max-width: 640px;
    margin: 0 auto;
}

.insight-lead {
    font-size: 24px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 8px;
    line-height: 1.4;
}

.insight-headline {
    font-size: 48px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 32px;
    letter-spacing: -0.03em;
    line-height: 1.2;
}

.insight-headline strong {
    color: var(--color-yellow);
}

.insight-body {
    font-size: 16px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.6);
}

/* ===== Solution (解決策) ===== */
.solution {
    background: var(--color-bg);
}

.section-subtitle {
    font-size: 16px;
    color: var(--color-gray);
    margin-top: 12px;
    line-height: 1.6;
}

.solution-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.solution-card {
    background: var(--color-beige);
    border-radius: var(--radius);
    padding: 40px 28px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.solution-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.solution-icon {
    color: var(--color-green);
    margin-bottom: 20px;
}

.solution-card h3 {
    font-size: 17px;
    font-weight: 700;
    line-height: 1.5;
}

/* ===== Scenes (利用シーン - Solution内) ===== */
.scenes-sub {
    margin-top: 64px;
}

.scenes-sub-title {
    font-size: 20px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 28px;
    letter-spacing: -0.02em;
}

/* Bubbles */
.bubbles-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    padding: 0 20px;
}

.bubble-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: flex-start;
    gap: 12px;
}

.bubble {
    display: inline-block;
    position: relative;
}

.bubble-tail { display: none; }

.bubble-body {
    display: inline-block;
    background: #D2FF00;
    color: #282C1F;
    font-family: 'Zen Kaku Gothic New', sans-serif;
    font-weight: 500;
    letter-spacing: 0.02em;
    line-height: 1;
    white-space: nowrap;
    border-radius: 25px;
    position: relative;
    filter: drop-shadow(0 2px 6px rgba(0,0,0,0.1));
}

.bubble-body::after {
    content: '';
    position: absolute;
    left: 42%;
    bottom: 0;
    width: 37px;
    height: 27px;
    transform: translateY(90%);
    background: url("data:image/svg+xml,%3Csvg viewBox='0 0 37 27' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M37 27C37 27 0 25.527 0 0H18.946C18.946 23.073 37 27 37 27Z' fill='%23D2FF00'/%3E%3C/svg%3E") no-repeat center / contain;
}

.bubble-xs .bubble-body { font-size: 16px; padding: 12px 24px; border-radius: 24px; }
.bubble-xs .bubble-body::after { width: 30px; height: 21px; }
.bubble-sm .bubble-body { font-size: 21px; padding: 15px 33px; border-radius: 30px; }
.bubble-sm .bubble-body::after { width: 39px; height: 28px; }
.bubble-md .bubble-body { font-size: 24px; padding: 18px 38px; border-radius: 34px; }
.bubble-md .bubble-body::after { width: 48px; height: 34px; }
.bubble-lg .bubble-body { font-size: 30px; padding: 21px 48px; border-radius: 38px; }
.bubble-lg .bubble-body::after { width: 60px; height: 43px; }
.bubble-xl .bubble-body { font-size: 38px; padding: 27px 60px; border-radius: 44px; }
.bubble-xl .bubble-body::after { width: 72px; height: 52px; }

/* ===== Trust (安心設計) ===== */
.trust {
    background: var(--color-beige);
}

.trust-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.trust-item {
    text-align: center;
}

.trust-icon {
    color: var(--color-green);
    margin-bottom: 16px;
}

.trust-item h3 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 8px;
}

.trust-item p {
    font-size: 14px;
    color: var(--color-gray);
    line-height: 1.7;
}

/* ===== How To ===== */
.howto {
    background: var(--color-beige);
}

.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.step {
    text-align: center;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-yellow);
    color: var(--color-dark);
    font-size: 20px;
    font-weight: 700;
    border-radius: 50%;
    margin-bottom: 24px;
}

.step-visual {
    margin-bottom: 24px;
}

.step-mask {
    width: 180px;
    height: 390px;
    border-radius: 32px;
    overflow: hidden;
    margin: 0 auto;
    position: relative;
    box-shadow:
        0 0 0 5px #1a1a1a,
        0 0 0 7px #333,
        0 16px 48px rgba(0, 0, 0, 0.18),
        0 4px 12px rgba(0, 0, 0, 0.08);
}

.step-mask img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
}

.step h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}

.step p {
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-gray);
}

/* ===== Screenshots ===== */
.screenshots {
    background: var(--color-bg);
}

.carousel-wrapper {
    position: relative;
    width: 100%;
}

.screenshots-carousel {
    display: flex;
    gap: 48px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scroll-behavior: smooth;
    padding: 30px 80px;
}

.screenshots-carousel::-webkit-scrollbar {
    display: none;
}

.screenshot-item {
    flex: 0 0 auto;
    scroll-snap-align: center;
}

/* Carousel arrows */
.carousel-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid var(--color-light-gray);
    background: var(--color-bg);
    color: var(--color-dark);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.carousel-arrow:hover {
    background: var(--color-dark);
    color: #fff;
    border-color: var(--color-dark);
}

.carousel-arrow-left {
    left: 12px;
}

.carousel-arrow-right {
    right: 12px;
}

.screenshot-mask {
    width: 220px;
    height: 477px;
    border-radius: 30px;
    overflow: hidden;
    position: relative;
    box-shadow:
        0 0 0 5px #1a1a1a,
        0 0 0 7px #333,
        0 16px 48px rgba(0, 0, 0, 0.18),
        0 4px 12px rgba(0, 0, 0, 0.08);
}

.screenshot-mask img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
}

/* ===== VOICEVOX Credits ===== */
.credits {
    background: var(--color-beige);
    padding: 80px 0;
}

.credits-header {
    text-align: center;
    margin-bottom: 40px;
}

.credits-label {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-green);
    margin-bottom: 8px;
}

.credits-title {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0.02em;
    margin-bottom: 12px;
}

.credits-subtitle {
    font-size: 14px;
    color: var(--color-gray);
    line-height: 1.6;
}

.credits-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 12px;
    max-width: 800px;
    margin: 0 auto;
}

.credit-item {
    background: var(--color-bg);
    border: 1px solid var(--color-light-gray);
    border-radius: var(--radius-sm);
    padding: 14px 12px;
    text-align: center;
    font-size: 14px;
    font-weight: 500;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.credit-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.credits-note {
    text-align: center;
    margin-top: 32px;
    font-size: 13px;
    color: var(--color-gray);
}

.credits-note a {
    color: var(--color-green);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.credits-note a:hover {
    color: var(--color-dark);
}

/* ===== Download CTA ===== */
.download {
    background: var(--color-dark);
    text-align: center;
}

.download-content h2 {
    color: #fff;
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.download-content p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 16px;
    margin-bottom: 36px;
}

.download .btn-primary {
    background: var(--color-yellow);
    color: var(--color-dark);
}

.download .btn-primary:hover {
    background: #c4f000;
}

/* ===== Footer ===== */
footer {
    background: #F4F4ED;
    padding: 48px 0 32px;
    border-top: none;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 32px;
}

.footer-brand-link {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.footer-logo-img {
    width: 59px;
    height: 35px;
}

.footer-tagline {
    font-size: 14px;
    font-weight: 500;
    color: #282C1F;
    line-height: 1.4;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: rgba(40, 44, 31, 0.7);
    font-size: 11px;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: #282C1F;
}

.footer-bottom {
    border-top: 1px solid rgba(40, 44, 31, 0.15);
    padding-top: 24px;
}

.footer-bottom p {
    font-size: 12px;
    color: rgba(40, 44, 31, 0.4);
}

/* ===== Scroll Animations ===== */
[data-animate] {
    opacity: 0;
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
                transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

[data-animate="fade-up"] {
    transform: translateY(40px);
}

[data-animate].animated {
    opacity: 1;
    transform: translateY(0) translateX(0) scale(1);
}

[data-delay="100"] { transition-delay: 0.1s; }
[data-delay="200"] { transition-delay: 0.2s; }
[data-delay="300"] { transition-delay: 0.3s; }
[data-delay="400"] { transition-delay: 0.4s; }
[data-delay="500"] { transition-delay: 0.5s; }
[data-delay="600"] { transition-delay: 0.6s; }

@media (prefers-reduced-motion: reduce) {
    [data-animate] {
        opacity: 1;
        transform: none;
        transition: none;
    }
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-visual {
        flex: none;
    }

    .hero-cta {
        display: flex;
        justify-content: center;
    }

    .steps {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px;
    }
}

@media (max-width: 768px) {
    section {
        padding: 72px 0;
    }

    .hero {
        padding: 0;
        aspect-ratio: 5 / 7;
    }

    .hero > .container {
        display: flex;
        align-items: flex-start;
        height: 100%;
        padding-top: 32px;
    }

    .hero-content {
        text-align: left;
    }

    .hero-title {
        font-size: 26px;
    }

    .hero-subtitle {
        font-size: 18px;
        margin-bottom: 20px;
    }

    .hero-cta {
        justify-content: flex-start !important;
    }

    .hero-cta .btn {
        font-size: 14px;
        padding: 12px 24px;
    }

    .hero-bg {
        background: center center / cover no-repeat;
    }

    .hero-bg-1 { background-image: url('../assets/hero-1_M.jpg'); }
    .hero-bg-2 { background-image: url('../assets/hero-2_M.jpg'); }
    .hero-bg-3 { background-image: url('../assets/hero-3_M.jpg'); }
    .hero-bg-4 { background-image: url('../assets/hero-4_M.jpg'); }

    .hero-visual-desktop {
        display: none;
    }

    .hero-visual-mobile {
        display: block;
        padding: 48px 0;
        background: var(--color-beige);
        text-align: center;
    }

    .hero-title {
        font-size: 36px;
    }

    .section-title {
        font-size: 26px;
    }

    .insight-headline {
        font-size: 36px;
    }

    .insight-lead {
        font-size: 20px;
    }

    .solution-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }

    .bubble-row { gap: 10px; }
    .bubbles-wrap { gap: 18px; }
    .bubble-xl .bubble-body { font-size: 17px; padding: 10px 24px; }
    .bubble-lg .bubble-body { font-size: 14px; padding: 9px 20px; }
    .bubble-md .bubble-body { font-size: 12px; padding: 8px 16px; }
    .bubble-sm .bubble-body { font-size: 10px; padding: 7px 14px; }
    .bubble-xs .bubble-body { font-size: 9px; padding: 6px 12px; }

    .trust-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
        gap: 40px;
    }

    .steps {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .credits-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .header-nav {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    .download-content h2 {
        font-size: 28px;
    }

    .footer-content {
        flex-direction: column;
        gap: 24px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 30px;
    }

    .phone-mask {
        width: 240px;
        height: 520px;
        border-radius: 36px;
    }

    .bubble-body { white-space: normal; }
    .bubble-row { gap: 8px; }
    .bubbles-wrap { gap: 16px; }

    .empathy-checklist li {
        font-size: 15px;
    }

    .empathy-conclusion {
        font-size: 22px;
    }
}