:root {
    /* ── Background ── */
    --bg: hsl(230 20% 5.5%);

    /* ── UI chrome ── */
    --ink: #e0e0e0;
    --soft: #BBB;
    --line: rgba(142, 167, 154, .15);
    --accent: hsl(210 55% 55%);
    --accent-dim: hsla(210, 55%, 55%, .10);

    /* ── #1 Yamato key colors (Pattern 02 桜鼠×縹 Vivid) ── */
    --k-n-bg: hsl(230 5% 12%);
    --k-n-tx: hsl(230 5% 42%);

    --k-l-bg: hsl(210 55% 27%);
    --k-l-tx: hsl(210 60% 88%);

    --k-la-bg: hsl(210 55% 27%);
    --k-la-tx: hsl(210 60% 95%);

    --k-r-bg: hsl(345 48% 24%);
    --k-r-tx: hsl(345 52% 86%);

    --k-ra-bg: hsl(345 58% 30%);
    --k-ra-tx: hsl(345 62% 92%);



    /* ── #2 QWERTY key colors (Pattern J 朽葉 h=32°) ── */
    --k-q-bg: hsl(32 44% 20%);
    --k-q-tx: hsl(32 52% 60%);

    --k-qn-bg: hsl(32 22% 12%);
    --k-qn-tx: hsl(32 16% 30%);

    /* ── #3 Onishi key colors (green h=148) ── */
    --k-o-tx: #4E8A5F;
    --k-o-press-bg: hsl(148 35% 22%);
    --k-o-press-tx: hsl(148 45% 75%);

    /* ── Progress bar ── */
    --prog-track: hsl(230 5% 12%);
    --prog-fill: hsl(210 55% 42%);

    /* ── UI text shades ── */
    --ink-mid: #BBB;
    --ink-muted: #666;
    --ink-dim: #888;
    --ink-soft: #999;

    --ink-white: #fff;
    --ink-ghost: #2a2a2a;
    --border-subtle: #333;

    /* ── Glow / box-shadow ── */
    --glow-blue: hsla(210, 55%, 55%, .35);
    --glow-blue-soft: hsla(210, 55%, 55%, .4);
    --glow-pink: hsla(345, 52%, 50%, .35);
    --glow-pink-soft: hsla(345, 62%, 92%, .3);
    --glow-amber: hsla(32, 52%, 60%, .15);
    --glow-amber-soft: hsla(32, 52%, 60%, .3);
    --glow-green: hsla(148, 45%, 50%, .15);
    --glow-green-soft: hsla(148, 45%, 50%, .4);

    /* ── Typing compare key states ── */
    --tc-y-press-bg: hsl(230 8% 16%);
    --tc-y-press-tx: #ddd;
    --tc-y-done-bg: hsl(230 5% 10%);
    --tc-y-done-tx: hsl(230 5% 28%);
    --tc-q-done-bg: hsl(32 18% 9%);
    --tc-q-done-tx: hsl(32 16% 26%);
}

* {
    box-sizing: border-box;
    margin: 0
}

body {
    min-height: 100vh;
    background: var(--bg);
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
    color: var(--ink);
    font-family: "Outfit", "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", sans-serif;
    overflow-x: hidden
}

@media (max-width: 600px) {

    html,
    body {
        height: 100%;
        overflow: hidden
    }
}

.page {
    min-height: 100vh;
    width: min(1100px, 94vw);
    margin: 0 auto;
    padding: 28px 20px 24px;
    display: grid;
    grid-template-rows: auto auto 1fr auto
}

@media (max-width: 600px) {
    .page {
        height: 100dvh;
        min-height: unset;
        overflow: hidden;
        display: flex;
        flex-direction: column
    }
}

.header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    padding-bottom: 16px
}

.quest {
    font-size: 16px;
    font-weight: 400;
    letter-spacing: .04em;
    color: var(--soft);
    opacity: .7
}

.quest em {
    font-style: normal;
    color: var(--soft)
}

.tagline {
    font-size: 16px;
    font-weight: 300;
    letter-spacing: .02em;
    color: var(--soft);
    opacity: .65
}

/* progress nav */
.progress-nav {
    display: flex;
    gap: 3px
}

.prog-col {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px
}

.prog-col[hidden] {
    display: none
}

.prog-seg {
    height: 3px;
    background: var(--prog-track);
    border-radius: 2px;
    overflow: hidden;
    position: relative
}

.prog-seg .fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 0%;
    background: var(--prog-fill);
    border-radius: 2px;
    transition: width 300ms ease
}

.prog-label {
    font-size: 14px;
    font-weight: 400;
    letter-spacing: .02em;
    color: var(--ink-muted);
    cursor: pointer;
    transition: all 140ms ease;
    user-select: none;
    padding: 2px 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis
}

.prog-label:hover {
    color: var(--ink-dim)
}

.prog-col.active .prog-label {
    color: var(--accent)
}

/* content area */
.content-area {
    display: grid;
    grid-template-rows: auto auto;
    gap: 36px;
    place-content: center
}

.text-zone {
    display: grid;
    place-content: center;
    height: 200px;
    text-align: center;
    overflow: hidden
}

.text-zone.expanded {
    overflow: visible
}


.text-zone.expanded .slide-body {
    overflow: visible
}

/* intro-slide: keep heading + body vertically anchored */
.intro-slide {
    --slide-heading-h: 52px;
    --slide-body-h: 90px
}

.kb-zone {
    display: grid;
    place-content: end center;
    height: calc(3 * clamp(50px, 5vw, 68px) + 80px);
    overflow: visible
}

.section {
    display: none
}

.section.active {
    display: contents
}

/* intro slides */
.intro-slide {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    text-align: center
}

.intro-slide.active {
    display: flex
}

.slide-heading {
    height: 52px;
    display: grid;
    place-content: end center;
    width: 100%;
    flex-shrink: 0
}

.slide-heading:has(.tg-grid) {
    height: auto
}

#sec-practice-text .slide-body {
    height: 48px
}

.slide-heading .title {
    font-size: clamp(28px, 4vw, 48px);
    font-weight: 700;
    letter-spacing: .06em;
    line-height: 1
}

.slide-heading .h3 {
    font-size: clamp(16px, 2vw, 24px);
    font-weight: 600
}

.slide-body {
    font-size: clamp(14px, 1.4vw, 18px);
    color: var(--soft);
    line-height: 1.7;
    max-width: 600px;
    text-align: center;
    height: 90px;
    overflow: hidden;
    flex-shrink: 0
}

.slide-body a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 2px
}

/* YouTube embed (rendered inside kb-zone) */
.slide-youtube {
    width: 100%;
    height: 100%;
    border-radius: 8px;
    overflow: hidden;
}

.slide-youtube iframe {
    width: 100%;
    height: 100%;
    border: none;
    border-radius: 8px;
}

.kb-zone:has(.slide-youtube) {
    place-content: stretch;
    place-items: center;
}

/* keyboard — BORDERLESS flat design */
.kb {
    display: grid;
    gap: 8px
}

.kb .row {
    display: flex;
    justify-content: center;
    gap: 6px
}

.kb .row:nth-child(2) {
    padding-left: 20px
}

.kb .row:nth-child(3) {
    padding-left: 40px
}

.key {
    width: clamp(46px, 4.5vw, 64px);
    height: clamp(50px, 5vw, 68px);
    border-radius: 8px;
    display: grid;
    place-items: center;
    position: relative;
    font-family: "Outfit", sans-serif;
    border: none;
    box-shadow: none;
    transition: all 160ms ease
}

.key .ym {
    font-size: clamp(16px, 1.6vw, 22px);
    font-weight: 400;
    line-height: 1
}

.key.st-n {
    background: var(--k-n-bg);
    color: var(--k-n-tx)
}

.key.st-q {
    background: var(--k-q-bg);
    color: var(--k-q-tx)
}

.key.st-qn {
    background: var(--k-qn-bg);
    color: var(--k-qn-tx)
}

.key.st-l {
    background: var(--k-l-bg);
    color: var(--k-l-tx)
}

.key.st-la {
    background: var(--k-la-bg);
    color: var(--k-la-tx)
}



.key.st-r {
    background: var(--k-r-bg);
    color: var(--k-r-tx)
}

.key.st-ra {
    background: var(--k-ra-bg);
    color: var(--k-ra-tx)
}



.key.home::after {
    content: "";
    position: absolute;
    bottom: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 12px;
    height: 2px;
    border-radius: 1px;
    background: rgba(255, 255, 255, .3)
}

.kb.split .row .gap-sp {
    width: clamp(24px, 3vw, 48px);
    flex-shrink: 0
}

.kb.split .lg,
.kb.split .rg {
    display: flex;
    gap: 6px
}

.kb.split {
    position: relative;
    padding-bottom: 24px
}

.kb:not(.split) {
    padding-bottom: 24px
}

/* Interactive key flash */
.key.key-flash-l {
    background: var(--k-la-bg) !important;
    color: var(--k-la-tx) !important;
    box-shadow: 0 0 14px var(--glow-blue);
    transform: scale(1.08);
    transition: all 60ms ease
}



.key.key-flash-r {
    background: var(--k-ra-bg) !important;
    color: var(--k-ra-tx) !important;
    box-shadow: 0 0 14px var(--glow-pink);
    transform: scale(1.08);
    transition: all 60ms ease
}




/* prompt */
.prompt-pair {
    display: flex;
    justify-content: center
}

.prompt-cell {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    min-width: clamp(40px, 6vw, 64px)
}

.prompt-cell .ja {
    font-size: clamp(26px, 3.6vw, 42px);
    line-height: 1
}

.prompt-cell .ro {
    font-size: clamp(14px, 1.6vw, 20px);
    color: var(--soft);
    line-height: 1
}

.prompt-cell.done .ja,
.prompt-cell.done .ro {
    opacity: .3
}

.prompt-cell.active .ro {
    color: var(--k-ra-tx);
    font-weight: 700;
    text-shadow: 0 0 18px var(--glow-pink-soft)
}

/* Typing Game — unified grid */
.tg-grid {
    display: flex;
    justify-content: center;
    gap: 16px
}

.tg-col {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px
}

.tg-k {
    font-size: clamp(28px, 4vw, 48px);
    font-weight: 700;
    color: var(--ink-muted);
    transition: all 200ms ease
}

.tg-k.done {
    opacity: .3
}

.tg-k.active {
    color: var(--ink-white);
    font-weight: 700
}

.tg-r-cell {
    display: flex;
    gap: 2px;
    justify-content: center;
    font-family: "Outfit", sans-serif;
    font-size: clamp(18px, 2vw, 26px);
    letter-spacing: .03em
}

.tg-r {
    color: var(--ink-muted)
}

.tg-r.done {
    opacity: .4
}

/* Active romaji: vowel = pink (right hand), consonant = blue (left hand) */
.tg-r.tg-rv {
    color: hsl(345 58% 55%);
    font-weight: 700
}

.tg-r.tg-rc {
    color: var(--accent);
    font-weight: 700
}

.tg-prog {
    font-size: 14px;
    color: var(--ink-muted);
    margin-top: 4px
}

.tg-done {
    color: var(--accent);
    font-size: clamp(16px, 2vw, 22px);
    line-height: 1.7
}

.key.tg-hl {
    animation: tg-pulse-l 1.2s ease-in-out infinite
}

.key.tg-hr {
    animation: tg-pulse-r 1.2s ease-in-out infinite
}

@keyframes tg-pulse-l {

    0%,
    100% {
        box-shadow: 0 0 4px var(--glow-blue)
    }

    50% {
        box-shadow: 0 0 14px var(--glow-blue-soft);
        transform: scale(1.05)
    }
}

@keyframes tg-pulse-r {

    0%,
    100% {
        box-shadow: 0 0 4px var(--glow-pink)
    }

    50% {
        box-shadow: 0 0 14px var(--glow-pink-soft);
        transform: scale(1.05)
    }
}

/* resources */
.res-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-width: 600px;
    margin: 0 auto
}

.res-item {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 0;
    background: none;
    border: none;
    text-decoration: none;
    color: var(--ink);
    transition: color 160ms ease
}

.res-item:hover {
    color: var(--accent)
}

.res-icon {
    font-size: 18px;
    flex-shrink: 0;
    opacity: .6
}

.res-body {
    display: flex;
    flex-direction: column;
    gap: 4px
}

.res-title {
    font-size: 14px;
    font-weight: 600
}

.res-meta {
    font-size: 14px;
    font-weight: 300;
    color: var(--soft);
    opacity: .6
}

/* FAQ */
.faq-section {
    max-width: 600px;
    margin: 20px auto 0;
    padding-top: 0
}

.faq-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--soft);
    margin-bottom: 12px;
    letter-spacing: .04em
}

.faq-item {
    padding: 0;
    background: none;
    border: none
}

.faq-item+.faq-item {
    margin-top: 16px
}

.faq-q {
    font-size: 14px;
    font-weight: 600;
    color: var(--ink);
    margin-bottom: 8px
}

.faq-a {
    font-size: 14px;
    font-weight: 300;
    color: var(--soft);
    line-height: 1.7
}

/* footer */
.footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 16px;
    border-top: 1px solid var(--line)
}

.nav-hint {
    display: flex;
    gap: 16px;
    font-size: 16px;
    font-weight: 300;
    color: var(--soft);
    opacity: .45
}

.nav-hint kbd {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 18px;
    padding: 0 4px;
    border: 1px solid var(--border-subtle);
    border-radius: 3px;
    font-size: 16px;
    color: var(--soft);
    background: var(--prog-track);
    margin-right: 4px
}

.brand {
    font-size: 16px;
    font-weight: 400;
    letter-spacing: .04em;
    color: var(--soft);
    opacity: .6
}

.brand em {
    font-style: normal;
    color: var(--soft)
}

/* ---- typing compare slide ---- */
.tc-wrap {
    display: flex;
    gap: 32px;
    width: 100%;
    justify-content: center
}

.tc-panel {
    flex: 1;
    max-width: 480px;
    display: flex;
    flex-direction: column
}

.tc-panel .tc-title {
    font-size: 18px;
    font-weight: 600;
    letter-spacing: .03em;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 28px
}

.tc-panel.tc-q .tc-title {
    color: var(--k-q-tx)
}

.tc-panel.tc-y .tc-title {
    color: var(--accent)
}

.tc-kb-wrap {
    position: relative;
    padding: 4px;
    margin-top: auto
}

.tc-kb {
    display: grid;
    gap: 3px
}

.tc-kb .row {
    display: flex;
    justify-content: center;
    gap: 2px
}

.tc-kb .row:nth-child(2) {
    padding-left: 10px
}

.tc-kb .row:nth-child(3) {
    padding-left: 20px
}

.tc-key {
    width: clamp(24px, 2.8vw, 34px);
    height: clamp(26px, 3vw, 36px);
    border-radius: 4px;
    display: grid;
    place-items: center;
    position: relative;
    font-size: clamp(9px, 1vw, 12px);
    font-weight: 400;
    border: none;
    box-shadow: none;
    transition: all .1s ease
}

.tc-y .tc-key {
    background: var(--k-n-bg);
    color: var(--k-n-tx)
}

.tc-q .tc-key {
    background: var(--k-n-bg);
    color: var(--k-n-tx)
}

.tc-key.home::after {
    content: "";
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: 7px;
    height: 1.5px;
    border-radius: 1px;
    background: rgba(255, 255, 255, .18)
}

.tc-y .tc-key.tc-pressing {
    background: var(--tc-y-press-bg);
    color: var(--tc-y-press-tx);
    box-shadow: 0 0 8px rgba(255, 255, 255, .06);
    transform: scale(1.08)
}

.tc-y .tc-key.tc-pressed {
    /* color set by JS inline style (saturation animation) */
}

.tc-q .tc-key.tc-pressing {
    background: var(--k-q-bg);
    color: var(--k-q-tx);
    box-shadow: 0 0 8px var(--glow-amber);
    transform: scale(1.08)
}

.tc-q .tc-key.tc-pressed {
    /* color set by JS inline style (saturation animation) */
}

.tc-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 5;
    overflow: visible
}

.tc-path {
    stroke-linecap: round;
    stroke-width: 1.5;
    fill: none;
    opacity: 0;
    animation: tcFade .15s ease forwards
}

@keyframes tcFade {
    to {
        opacity: .5
    }
}

.tc-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    position: absolute;
    pointer-events: none;
    z-index: 1;
    opacity: .15;
    transition: none
}

.tc-y .tc-dot.tc-lh,
.tc-y .tc-dot.tc-rh {
    background: var(--accent);
    box-shadow: 0 0 4px var(--glow-blue-soft)
}

.tc-q .tc-dot.tc-lh,
.tc-q .tc-dot.tc-rh {
    background: var(--k-q-tx);
    box-shadow: 0 0 4px var(--glow-amber-soft)
}

.tc-dot.tc-active {
    opacity: .35;
    transform: scale(1.3);
    transition: left .12s cubic-bezier(.4, 0, .2, 1), top .12s cubic-bezier(.4, 0, .2, 1), opacity .1s, transform .1s
}

.tc-phrase {
    font-size: clamp(16px, 2vw, 22px);
    text-align: center;
    margin-bottom: 4px;
    letter-spacing: .03em;
    min-height: 1.2em
}

/* per-panel typing roma display */
.tc-typing-inline {
    display: flex;
    gap: 1px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 6px;
    min-height: 22px
}

.tc-word-gap {
    width: 6px
}

.tc-line-break {
    width: 100%;
    height: 0
}

.tc-roma {
    font-size: clamp(11px, 1.2vw, 15px);
    min-width: 9px;
    text-align: center;
    transition: all .12s;
    letter-spacing: .02em
}

/* Shared typing display roma colors (synced to Yamato) */
.tc-mock-box .tc-roma {
    color: hsl(210 15% 28%)
}

.tc-mock-box .tc-roma.tc-r-active {
    color: var(--accent);
    font-weight: 700
}

.tc-mock-box .tc-roma.tc-r-done {
    color: hsl(210 10% 16%)
}

/* Onishi roma colors */
.tc-o .tc-roma {
    color: hsl(148 15% 28%)
}

.tc-o .tc-roma.tc-r-active {
    color: var(--k-o-tx);
    font-weight: 700
}

.tc-o .tc-roma.tc-r-done {
    color: hsl(148 10% 16%)
}

.tc-mock-box {
    min-height: calc(3 * clamp(50px, 5vw, 68px) + 40px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 6px;
    padding-bottom: 20px;
    animation: tcBoxIn .15s ease
}

@keyframes tcBoxIn {
    from {
        opacity: 0
    }

    to {
        opacity: 1
    }
}

.tc-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 14px;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: .02em;
    margin-bottom: 6px;
    height: 28px
}

.tc-stats .tc-sep {
    margin: 0 8px;
    opacity: .25
}

.tc-q .tc-stats {
    color: var(--k-q-tx);
    opacity: .6
}

.tc-y .tc-stats {
    color: var(--accent);
    opacity: .6
}

/* Onishi (orange) panel */
.tc-panel.tc-o .tc-title {
    color: var(--k-o-tx)
}

.tc-o .tc-key {
    background: var(--k-n-bg);
    color: var(--k-n-tx)
}

.tc-o .tc-key.tc-pressing {
    background: var(--k-o-press-bg);
    color: var(--k-o-press-tx);
    box-shadow: 0 0 8px var(--glow-green);
    transform: scale(1.08)
}

.tc-o .tc-key.tc-pressed {
    /* color set by JS inline style (saturation animation) */
}

.tc-o .tc-dot.tc-lh,
.tc-o .tc-dot.tc-rh {
    background: var(--k-o-tx);
    box-shadow: 0 0 4px var(--glow-green-soft)
}

.tc-o .tc-stats {
    color: var(--k-o-tx);
    opacity: .6
}

@media(max-width:860px) {
    .kb .row {
        gap: 4px
    }

    .kb {
        gap: 5px
    }

    .kb .row:nth-child(2) {
        padding-left: 14px
    }

    .kb .row:nth-child(3) {
        padding-left: 28px
    }

    .kb.split .row .gap-sp {
        width: clamp(12px, 2vw, 24px)
    }

    .tc-wrap {
        flex-direction: column;
        align-items: center
    }

    .tc-panel {
        max-width: 100%
    }

    .tc-key {
        width: clamp(28px, 7vw, 38px);
        height: clamp(30px, 7.5vw, 40px);
        font-size: clamp(10px, 2.5vw, 13px)
    }
}

/* ── Mobile ── */
@media(max-width:600px) {
    .page {
        padding: 16px 12px 16px;
        width: 100%
    }

    /* Header: stack vertically */
    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 2px;
        padding-bottom: 16px;
        flex-shrink: 0
    }

    .progress-nav {
        flex-shrink: 0
    }

    .quest {
        font-size: 14px
    }

    .tagline {
        font-size: 14px
    }

    /* Progress nav labels */
    .prog-label {
        font-size: 14px
    }

    /* Content area: flex column, top-aligned with padding */
    .content-area {
        display: flex;
        flex-direction: column;
        flex: 1;
        min-height: 0;
        gap: 12px;
        padding-top: 4vh
    }

    /* Text zone: fixed height to prevent shift */
    .text-zone {
        flex: 0 0 156px;
        height: 156px;
        min-height: unset;
        display: grid;
        place-content: center;
        overflow: hidden
    }

    /* Intro slide: fixed-height regions so keyboard never shifts */
    .intro-slide {
        --slide-heading-h: 44px;
        --slide-body-h: 100px
    }

    .slide-heading {
        height: var(--slide-heading-h);
        padding-bottom: 0;
        flex-shrink: 0
    }

    .slide-heading .h3 {
        font-size: 24px
    }

    .slide-heading .title {
        font-size: 28px
    }

    .slide-body {
        height: var(--slide-body-h);
        overflow: hidden;
        font-size: 16px;
        line-height: 1.65;
        flex-shrink: 0
    }

    /* Hide <br> inside slide-body on mobile */
    .slide-body br {
        display: none
    }

    /* Keyboard zone: directly under text, no bottom-pinning */
    .kb-zone {
        height: auto;
        min-height: calc(3 * clamp(38px, 10vw, 50px) + 40px);
        flex-shrink: 0;
        pointer-events: none;
        -webkit-tap-highlight-color: transparent
    }

    .footer {
        flex-shrink: 0
    }

    /* Keys: square aspect ratio */
    .key {
        width: clamp(25px, 6.8vw, 46px);
        height: clamp(25px, 6.8vw, 46px);
        border-radius: 6px
    }

    /* Home position mark: reposition for smaller keys */
    .key.home::after {
        bottom: 3px;
        width: 8px;
        height: 1.5px
    }

    .key .ym {
        font-size: clamp(11px, 3vw, 16px)
    }

    .kb .row {
        gap: 2px
    }

    .kb {
        gap: 3px
    }

    .kb .row:nth-child(2) {
        padding-left: 8px
    }

    .kb .row:nth-child(3) {
        padding-left: 16px
    }

    /* Disable split layout on mobile */
    .kb.split .row .gap-sp {
        display: none
    }

    .kb.split .lg,
    .kb.split .rg {
        display: contents
    }

    /* Prompt cells */
    .prompt-cell {
        min-width: clamp(32px, 8vw, 48px)
    }

    .prompt-cell .ja {
        font-size: clamp(20px, 5.5vw, 32px)
    }

    .prompt-cell .ro {
        font-size: clamp(12px, 3vw, 16px)
    }

    /* Footer: stack and hide nav hint */
    .footer {
        flex-direction: column;
        align-items: center;
        gap: 8px;
        padding-top: 12px
    }

    .nav-hint {
        display: none
    }

    .brand {
        font-size: 13px
    }

    /* Typing compare */
    .tc-wrap {
        gap: 16px
    }

    .tc-key {
        width: clamp(20px, 6vw, 32px);
        height: clamp(22px, 6.5vw, 34px);
        font-size: clamp(8px, 2vw, 11px)
    }

    .tc-kb .row {
        gap: 1px
    }

    .tc-kb {
        gap: 2px
    }

    .tc-kb .row:nth-child(2) {
        padding-left: 5px
    }

    .tc-kb .row:nth-child(3) {
        padding-left: 10px
    }

    .tc-panel .tc-title {
        font-size: 14px;
        margin-bottom: 4px;
        height: 22px
    }

    .tc-phrase {
        font-size: clamp(13px, 3.5vw, 18px)
    }

    .tc-typing-inline {
        margin-bottom: 4px;
        min-height: 18px
    }

    .tc-roma {
        font-size: 10px;
        min-width: 7px
    }

    .tc-stats {
        font-size: 11px;
        height: 20px
    }

    .tc-mock-box {
        min-height: calc(3 * clamp(38px, 10vw, 50px) + 20px)
    }

    /* Resources / FAQ */
    .res-list {
        max-width: 100%
    }

    .faq-section {
        max-width: 100%
    }

    .res-title {
        font-size: 13px
    }

    .res-meta {
        font-size: 12px
    }

    .faq-q {
        font-size: 13px
    }

    .faq-a {
        font-size: 13px
    }
}