:root {
    --ink:          #0a0a0a;
    --ink-2:        #262626;
    --ink-3:        #525252;
    --ink-4:        #737373;
    --ink-5:        #a3a3a3;
    --ink-6:        #d4d4d4;

    --paper:        #ffffff;
    --paper-2:      #fafaf7;
    --paper-3:      #f4f4f0;
    --paper-4:      #ebebe6;

    --rule:         #e7e5e0;
    --rule-2:       #d6d3cc;

    --font-jp:  'Noto Sans JP', 'Inter', system-ui, sans-serif;
    --font-en:  'Inter', 'Noto Sans JP', system-ui, sans-serif;
    --font-mono: ui-monospace, 'SFMono-Regular', Menlo, Consolas, monospace;

    --t-eyebrow:    0.6875rem;
    --t-caption:    0.75rem;
    --t-small:      0.8125rem;
    --t-body:       0.9375rem;
    --t-lead:       1.0625rem;
    --t-h5:         1.125rem;
    --t-h4:         1.375rem;
    --t-h3:         1.75rem;
    --t-h2:         2.25rem;
    --t-h1:         clamp(2rem, 3.6vw, 2.75rem);

    --tracking-tight: -0.03em;
    --tracking-snug:  -0.015em;
    --tracking-wide:  0.04em;
    --tracking-eye:   0.14em;

    --shell-max:    1200px;
    --reading-max:  720px;
    --gutter:       clamp(1.25rem, 4vw, 3rem);

    --ease:         cubic-bezier(0.22, 0.61, 0.36, 1);
    --ease-out:     cubic-bezier(0.16, 1, 0.3, 1);
    --dur-1:        160ms;
    --dur-2:        280ms;
    --dur-3:        480ms;

    --shadow-md:    0 12px 28px -12px rgba(0, 0, 0, 0.35);

    --header-h:     72px;
    --z-menu:       300;
    --z-header:     400;

    color-scheme: light;
}

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

html {
    scroll-behavior: smooth;
}

html, body {
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-jp);
    font-size: var(--t-body);
    line-height: 1.8;
    color: var(--ink);
    background: var(--paper);
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; background: none; border: 0; padding: 0; }
img { display: block; max-width: 100%; }
h1, h2, h3, h4, h5, p { margin: 0; }

::selection { background: var(--ink); color: var(--paper); }

:focus-visible {
    outline: 2px solid var(--ink);
    outline-offset: 3px;
    border-radius: 2px;
}

.hidden { display: none !important; }
.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.shell {
    width: 100%;
    max-width: var(--shell-max);
    margin: 0 auto;
    padding-left: var(--gutter);
    padding-right: var(--gutter);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: var(--z-header);
    background: rgba(255, 255, 255, 0.82);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--rule);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
}

.wordmark {
    font-family: var(--font-en);
    font-weight: 900;
    font-size: 1.625rem;
    letter-spacing: -0.06em;
    color: var(--ink);
    transition: color var(--dur-1) var(--ease);
}
.wordmark:hover { color: var(--ink-3); }

.site-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.site-nav__link {
    font-size: var(--t-small);
    font-weight: 500;
    color: var(--ink-3);
    letter-spacing: var(--tracking-snug);
    transition: color var(--dur-1) var(--ease);
}
.site-nav__link:hover { color: var(--ink); }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.625rem;
    padding: 1rem 2rem;
    background: var(--ink);
    color: var(--paper);
    font-weight: 600;
    font-size: var(--t-body);
    letter-spacing: 0.02em;
    border-radius: 999px;
    transition: transform var(--dur-2) var(--ease-out), box-shadow var(--dur-2) var(--ease-out), background var(--dur-1) var(--ease);
}
.btn:hover {
    background: var(--ink-2);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn--small {
    padding: 0.5rem 1.25rem;
    font-size: var(--t-small);
}

.btn--invert {
    background: var(--paper);
    color: var(--ink);
}
.btn--invert:hover {
    background: var(--paper-3);
}

.btn--ghost {
    background: transparent;
    color: var(--ink-3);
    border: 1px solid var(--rule-2);
}
.btn--ghost:hover {
    background: var(--paper-3);
    color: var(--ink);
    box-shadow: none;
}

.menu-btn {
    display: none;
    padding: 0.5rem;
    color: var(--ink-3);
    position: relative;
    z-index: calc(var(--z-menu) + 10);
    transition: color var(--dur-1) var(--ease);
}
.menu-btn:hover { color: var(--ink); }
.menu-btn svg { width: 24px; height: 24px; display: block; }

.mobile-menu {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transform: translateY(-100%);
    transition: transform var(--dur-3) var(--ease-out), opacity var(--dur-3) var(--ease-out);
    pointer-events: none;
    z-index: var(--z-menu);
}
.mobile-menu.active {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.mobile-menu ul {
    list-style: none;
    margin: 0;
    padding: 0;
    text-align: center;
}
.mobile-menu li {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--dur-2) var(--ease-out), transform var(--dur-2) var(--ease-out);
    padding: 0.5rem 0;
}
.mobile-menu.active li {
    opacity: 1;
    transform: translateY(0);
}
.mobile-menu.active li:nth-child(1) { transition-delay: 0.20s; }
.mobile-menu.active li:nth-child(2) { transition-delay: 0.25s; }
.mobile-menu.active li:nth-child(3) { transition-delay: 0.30s; }
.mobile-menu.active li:nth-child(4) { transition-delay: 0.35s; }

.mobile-menu__link {
    display: block;
    padding: 0.5rem 1rem;
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: var(--tracking-snug);
    color: var(--ink);
    transition: color var(--dur-1) var(--ease);
}
.mobile-menu__link:hover { color: var(--ink-3); }

@media (max-width: 880px) {
    .site-nav { display: none; }
    .menu-btn { display: inline-flex; }
}

.hero {
    position: relative;
    display: flex;
    align-items: center;
    min-height: calc(100vh - var(--header-h));
    min-height: calc(100svh - var(--header-h));
    background-color: var(--ink);
    background-image: url('/image/Vocalis_Background.webp');
    background-image: image-set(
        url('/image/Vocalis_Background.avif') type('image/avif'),
        url('/image/Vocalis_Background.webp') type('image/webp')
    );
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color: var(--paper);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(10, 10, 10, 0.55) 0%, rgba(10, 10, 10, 0.65) 70%, rgba(10, 10, 10, 0.8) 100%);
}

.hero__inner {
    position: relative;
    width: 100%;
    text-align: center;
    padding-top: clamp(5rem, 14vh, 9rem);
    padding-bottom: clamp(6rem, 16vh, 10rem);
}

.eyebrow {
    font-family: var(--font-en);
    font-size: var(--t-eyebrow);
    font-weight: 700;
    letter-spacing: var(--tracking-eye);
    text-transform: uppercase;
    color: var(--ink-4);
}

.hero .eyebrow {
    color: rgba(255, 255, 255, 0.65);
    margin-bottom: 1.75rem;
}

.hero__title {
    font-size: clamp(2rem, 4.5vw + 0.5rem, 3.75rem);
    font-weight: 900;
    line-height: 1.25;
    letter-spacing: -0.04em;
    margin: 0 auto 1.75rem;
    max-width: 18em;
    text-shadow: 0 2px 24px rgba(0, 0, 0, 0.45);
}

.hero__title span { display: inline-block; }

.hero__lede {
    font-size: var(--t-lead);
    line-height: 1.95;
    color: rgba(255, 255, 255, 0.78);
    font-weight: 300;
    max-width: 34em;
    margin: 0 auto 3rem;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.hero__scroll {
    position: absolute;
    left: 50%;
    bottom: 2.25rem;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.6);
    transition: color var(--dur-1) var(--ease), transform var(--dur-2) var(--ease-out);
}
.hero__scroll:hover {
    color: var(--paper);
    transform: translateX(-50%) translateY(3px);
}
.hero__scroll svg {
    width: 2rem;
    height: 2rem;
    animation: hero-bob 2.4s var(--ease) infinite;
}
@keyframes hero-bob {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(6px); }
}
@media (prefers-reduced-motion: reduce) {
    .hero__scroll svg { animation: none; }
}

.btn--ghost-light {
    background: transparent;
    color: rgba(255, 255, 255, 0.85);
    border: 1px solid rgba(255, 255, 255, 0.4);
}
.btn--ghost-light:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--paper);
    box-shadow: none;
}

.section {
    padding-top: clamp(4rem, 10vh, 6.5rem);
    padding-bottom: clamp(4rem, 10vh, 6.5rem);
    background: var(--paper);
}

.section--tinted {
    background: var(--paper-3);
    border-top: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
}

.section--tinted .eyebrow {
    color: var(--ink-3);
}

.section-head {
    margin-bottom: 3rem;
}

.section-head .eyebrow { margin-bottom: 1rem; }

.section-head__title {
    font-size: var(--t-h2);
    font-weight: 900;
    letter-spacing: var(--tracking-tight);
    line-height: 1.25;
}
.section-head__title span { display: inline-block; }

.section-head__lede {
    margin-top: 1rem;
    color: var(--ink-3);
    font-weight: 300;
    max-width: 38em;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

@media (max-width: 880px) {
    .card-grid { grid-template-columns: 1fr; }
}

.card {
    border-top: 1px solid var(--rule-2);
    padding: 1.75rem 0 0;
    transition: border-color var(--dur-2) var(--ease);
}
.card:hover {
    border-top-color: var(--ink);
}

.card__title {
    font-size: var(--t-h5);
    font-weight: 700;
    letter-spacing: var(--tracking-snug);
    margin-bottom: 0.75rem;
}

.card__body {
    font-size: var(--t-small);
    line-height: 1.85;
    color: var(--ink-3);
}

.card__step {
    font-family: var(--font-en);
    font-size: var(--t-h3);
    font-weight: 900;
    line-height: 1;
    color: var(--ink-6);
    margin-bottom: 1rem;
}

.card__body code,
.faq-item__body code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: var(--paper-3);
    border: 1px solid var(--rule);
    border-radius: 4px;
    padding: 0.1em 0.4em;
}

.about-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: 3rem;
    align-items: center;
}
.about-grid .section-head { margin-bottom: 0; }

.stat-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    margin: 0;
}

.stat {
    border-top: 1px solid var(--rule-2);
    padding: 1.25rem 0 0;
}

.stat__num {
    font-family: var(--font-en);
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: var(--tracking-tight);
    line-height: 1;
    margin: 0 0 0.5rem;
}

.stat__unit {
    font-size: 1rem;
    font-weight: 700;
    margin-left: 0.25rem;
    color: var(--ink-3);
}

.stat__label {
    font-size: var(--t-caption);
    font-weight: 500;
    color: var(--ink-4);
    letter-spacing: var(--tracking-snug);
}

@media (max-width: 880px) {
    .about-grid { grid-template-columns: 1fr; gap: 2.5rem; }
}

.command-list {
    list-style: none;
    margin: 0;
    padding: 0;
    max-width: var(--reading-max);
    border-top: 1px solid var(--rule);
}

.command-list li {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.5rem 1.5rem;
    padding: 1.125rem 0.25rem;
    border-bottom: 1px solid var(--rule);
}

.command-list code {
    font-family: var(--font-mono);
    font-size: var(--t-small);
    font-weight: 600;
    background: var(--paper);
    border: 1px solid var(--rule-2);
    border-radius: 6px;
    padding: 0.2rem 0.6rem;
    white-space: nowrap;
}

.command-list .command-description {
    font-size: var(--t-small);
    color: var(--ink-3);
    flex: 1 1 16em;
}

.faq-list {
    max-width: var(--reading-max);
    border-top: 1px solid var(--rule);
}

.faq-item {
    border-bottom: 1px solid var(--rule);
}

.faq-item summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.25rem 0.25rem;
    font-size: var(--t-body);
    font-weight: 600;
    letter-spacing: var(--tracking-snug);
    cursor: pointer;
    list-style: none;
    transition: color var(--dur-1) var(--ease);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary:hover { color: var(--ink-3); }

.faq-item summary::after {
    content: '+';
    font-family: var(--font-en);
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--ink-4);
    flex-shrink: 0;
    transition: transform var(--dur-2) var(--ease-out);
}
.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item__body {
    padding: 0 0.25rem 1.5rem;
    font-size: var(--t-small);
    line-height: 1.95;
    color: var(--ink-3);
    max-width: 42em;
}
.card__body a,
.section-head__lede a {
    color: var(--ink);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.card__body a:hover,
.section-head__lede a:hover { color: var(--ink-3); }

.faq-item__body a {
    color: var(--ink);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.faq-item__body a:hover { color: var(--ink-3); }

.cta-band {
    background: var(--ink);
    color: var(--paper);
}

.cta-band__inner {
    padding-top: clamp(4rem, 10vh, 6rem);
    padding-bottom: clamp(4rem, 10vh, 6rem);
    text-align: center;
}

.cta-band .eyebrow { color: var(--ink-5); margin-bottom: 1.25rem; }

.cta-band__title {
    font-size: var(--t-h2);
    font-weight: 900;
    letter-spacing: var(--tracking-tight);
    line-height: 1.25;
    margin-bottom: 1.25rem;
}

.cta-band__lede {
    color: var(--ink-5);
    font-weight: 300;
    max-width: 32em;
    margin: 0 auto 2.5rem;
}

.site-footer {
    margin-top: auto;
    border-top: 1px solid var(--rule);
    background: var(--paper-2);
}

.site-footer__inner {
    padding-top: 3.5rem;
    padding-bottom: 3.5rem;
    text-align: center;
    font-size: var(--t-caption);
    color: var(--ink-4);
}

.site-footer__social {
    margin-bottom: 2rem;
}
.site-footer__social a {
    display: inline-flex;
    color: var(--ink-3);
    transition: color var(--dur-1) var(--ease), transform var(--dur-1) var(--ease);
}
.site-footer__social a:hover {
    color: var(--ink);
    transform: translateY(-2px);
}
.site-footer__social svg { width: 26px; height: 26px; }

.site-footer__nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.25rem 1.5rem;
    list-style: none;
    margin: 0 0 1rem;
    padding: 0;
}
.site-footer__nav a { transition: color var(--dur-1) var(--ease); }
.site-footer__nav a:hover { color: var(--ink); }

.site-footer__copy {
    color: var(--ink-4);
    margin-top: 1.5rem;
}

.last-updated {
    font-size: var(--t-caption);
    color: var(--ink-4);
    margin-top: 1rem;
}

.prose {
    max-width: var(--reading-max);
}

.prose h2 {
    font-size: var(--t-h5);
    font-weight: 700;
    letter-spacing: var(--tracking-snug);
    margin: 2.75rem 0 0.875rem;
    padding-top: 1.75rem;
    border-top: 1px solid var(--rule);
}

.prose p {
    font-size: var(--t-small);
    line-height: 2;
    color: var(--ink-2);
    margin-bottom: 1rem;
}

.prose ul {
    list-style: disc;
    margin: 0 0 1rem;
    padding-left: 1.5rem;
}

.prose ul ul {
    list-style: circle;
    margin: 0.5rem 0 0.5rem;
}

.prose li {
    font-size: var(--t-small);
    line-height: 2;
    color: var(--ink-2);
    margin-bottom: 0.375rem;
}

.prose strong { font-weight: 700; color: var(--ink); }

.prose a {
    color: var(--ink);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.prose a:hover { color: var(--ink-3); }

.prose dl {
    margin: 0;
    border-top: 1px solid var(--rule);
}

.prose dt {
    font-size: var(--t-small);
    font-weight: 700;
    padding-top: 1.25rem;
}

.prose dd {
    font-size: var(--t-small);
    line-height: 2;
    color: var(--ink-2);
    margin: 0.25rem 0 0;
    padding-bottom: 1.25rem;
    border-bottom: 1px solid var(--rule);
}

.chip-grid {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 0.75rem;
}

.chip-grid a {
    display: block;
    padding: 0.875rem 1.25rem;
    background: var(--paper);
    border: 1px solid var(--rule);
    border-radius: 10px;
    font-size: var(--t-small);
    font-weight: 600;
    letter-spacing: var(--tracking-snug);
    transition: border-color var(--dur-1) var(--ease), transform var(--dur-2) var(--ease-out), box-shadow var(--dur-2) var(--ease-out);
}
.chip-grid a:hover {
    border-color: var(--rule-2);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.plan-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    max-width: 880px;
}

@media (max-width: 880px) {
    .plan-grid { grid-template-columns: 1fr; }
}

.plan {
    border: 1px solid var(--rule-2);
    border-radius: 14px;
    padding: 2.25rem 2rem;
    display: flex;
    flex-direction: column;
}

.plan--premium {
    background: var(--ink);
    border-color: var(--ink);
    color: var(--paper);
}

.plan .eyebrow { margin-bottom: 1rem; }
.plan--premium .eyebrow { color: var(--ink-5); }

.plan__title {
    font-size: var(--t-h4);
    font-weight: 900;
    letter-spacing: var(--tracking-tight);
    margin-bottom: 0.375rem;
}

.plan__price {
    font-family: var(--font-en);
    font-size: var(--t-h3);
    font-weight: 900;
    letter-spacing: var(--tracking-tight);
    margin-bottom: 1.5rem;
}
.plan__price small {
    font-size: var(--t-small);
    font-weight: 500;
    color: var(--ink-4);
    margin-left: 0.375rem;
}
.plan--premium .plan__price small { color: var(--ink-5); }

.plan__features {
    list-style: none;
    margin: 0 0 2rem;
    padding: 0;
    border-top: 1px solid var(--rule);
    flex: 1;
}
.plan--premium .plan__features { border-top-color: var(--ink-2); }

.plan__features li {
    display: flex;
    align-items: baseline;
    gap: 0.625rem;
    font-size: var(--t-small);
    line-height: 1.8;
    color: var(--ink-2);
    padding: 0.625rem 0;
    border-bottom: 1px solid var(--rule);
}
.plan--premium .plan__features li {
    color: var(--ink-6);
    border-bottom-color: var(--ink-2);
}

.plan__features li::before {
    content: '✓';
    font-family: var(--font-en);
    font-weight: 700;
    flex-shrink: 0;
    color: var(--ink);
}
.plan--premium .plan__features li::before { color: var(--paper); }

.plan__note {
    font-size: var(--t-caption);
    color: var(--ink-4);
    margin-top: 0.875rem;
}
.plan--premium .plan__note { color: var(--ink-5); }