:root {
  color-scheme: dark;
  --canvas: #0c0f12;
  --surface: #14181c;
  --raised: #1e2429;
  --ink: #f2f5f7;
  --muted: #aab2b9;
  --divider: #2a3238;
  --accent: #3b8258;
  --accent-light: #93c8a5;
  --font: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans CJK SC", "Microsoft YaHei UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 108px; }
body { margin: 0; background: var(--canvas); color: var(--ink); font-family: var(--font); -webkit-font-smoothing: antialiased; }
body.modal-open { overflow: hidden; }
button, a, summary { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
button, a { touch-action: manipulation; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }
button, summary, a { outline-offset: 6px; }
:focus-visible { outline: 2px solid var(--accent-light); }
button { cursor: pointer; }
img { display: block; max-width: 100%; }
svg { flex-shrink: 0; }
h1, h2, h3, p { margin: 0; }
::selection { background: var(--accent); color: white; }
.icon-definitions { position: absolute; width: 0; height: 0; overflow: hidden; }
.icon { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.icon-small { width: 18px; height: 18px; }
.shell { width: min(1200px, calc(100% - 96px)); margin-inline: auto; }
.section { padding-block: 112px; }
.skip-link { position: fixed; top: -100px; left: 24px; z-index: 100; padding: 14px 24px; background: var(--accent); border-radius: 12px; }
.skip-link:focus { top: 12px; }

.site-header { position: relative; z-index: 20; border-bottom: 1px solid rgba(170,178,185,.1); }
.header-inner { min-height: 88px; display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 10px; flex-shrink: 0; }
.brand > img { width: 36px; height: 36px; border-radius: 11px; }
.brand > span { font-size: 29px; font-weight: 740; letter-spacing: -1.5px; line-height: 1; }
.brand-dot { color: var(--accent-light); }
.main-nav { display: flex; align-items: center; gap: 34px; font-size: 13px; font-weight: 550; }
.main-nav a { display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 48px; color: var(--muted); transition: color 160ms ease-out; }
.main-nav a:hover { color: var(--ink); }
.main-nav .nav-download { color: var(--ink); border: 1px solid var(--divider); border-radius: 12px; padding: 0 19px; gap: 12px; }
.main-nav .nav-download:hover { background: var(--raised); border-color: #485750; }
.menu-toggle { display: none; align-items: center; justify-content: center; width: 48px; height: 48px; background: transparent; border: 1px solid var(--divider); border-radius: 12px; }

.hero { position: relative; min-height: 682px; display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 16px; padding-top: 28px; padding-bottom: 28px; }
.hero-copy { position: relative; z-index: 3; padding-bottom: 12px; }
.hero-kicker { display: flex; align-items: center; gap: 12px; color: var(--accent-light); font-size: 13px; font-weight: 550; letter-spacing: .12em; margin-bottom: 28px; }
.tiny-wave { height: 18px; display: inline-flex; align-items: center; gap: 3px; }
.tiny-wave i { width: 2px; height: 8px; border-radius: 2px; background: var(--accent-light); }
.tiny-wave i:nth-child(2), .tiny-wave i:nth-child(4) { height: 14px; }
.tiny-wave i:nth-child(3) { height: 20px; }
h1 { font-size: clamp(44px, 4.5vw, 65px); font-weight: 730; letter-spacing: -.055em; line-height: 1.27; }
h1 span { color: var(--accent-light); }
.hero-description { max-width: 490px; margin-top: 26px; font-size: 16px; line-height: 1.95; color: var(--muted); }
.hero-actions { display: flex; align-items: center; gap: 28px; margin-top: 36px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 11px; min-height: 54px; border-radius: 12px; padding: 0 23px; font-size: 14px; font-weight: 620; transition: background 160ms ease-out, transform 160ms ease-out; }
.button-primary { background: var(--accent); color: #fff; border: 1px solid rgba(255,255,255,.08); }
.button-primary:hover { background: #467e5c; transform: translateY(-2px); }
.button-primary:active { transform: translateY(0); }
.text-link { min-height: 48px; display: inline-flex; align-items: center; gap: 12px; font-size: 14px; }
.text-link .icon { transition: transform 160ms ease-out; }
.text-link:hover .icon { transform: translateX(4px); }
.hero-note { display: flex; align-items: center; gap: 13px; margin-top: 27px; color: #8e999f; font-size: 11px; }
.note-divider { width: 3px; height: 3px; border-radius: 100%; background: #65756c; }
.hero-stage { position: relative; height: 610px; min-width: 0; isolation: isolate; }
.sound-rings { position: absolute; width: 535px; height: 535px; top: 38px; left: 50%; transform: translateX(-50%); z-index: -1; }
.sound-rings span { position: absolute; inset: 0; border: 1px solid rgba(147,200,165,.09); border-radius: 50%; }
.sound-rings span:nth-child(2) { inset: 50px; }
.sound-rings span:nth-child(3) { inset: 100px; }
.hero-stage::before { content: ""; position: absolute; z-index: -1; width: 390px; height: 475px; top: 76px; right: 16px; background: radial-gradient(ellipse, rgba(59,130,88,.18), rgba(12,15,18,0) 70%); }
.phone { display: block; position: relative; background: #11161a; border: 1px solid #49514d; border-radius: 29px; padding: 5px; box-shadow: 0 0 0 3px #1b2224, 0 20px 50px rgba(0,0,0,.35); line-height: 0; transition: transform 220ms ease-out, border-color 220ms ease-out; }
.phone img { width: 100%; height: auto; border-radius: 23px; }
.phone:hover { border-color: var(--accent-light); }
.hero-phone { position: absolute; }
.phone-back { width: 226px; left: 31px; top: 52px; transform: rotate(-8deg); }
.phone-back:hover { transform: rotate(-6deg) translateY(-5px); }
.phone-front { width: 254px; top: 21px; right: 37px; transform: rotate(7deg); z-index: 2; }
.phone-front:hover { transform: rotate(5deg) translateY(-5px); }
.stage-label { position: absolute; bottom: 9px; left: 50%; transform: translateX(-50%); white-space: nowrap; display: flex; align-items: center; gap: 12px; color: #7e8d86; font-size: 9px; font-weight: 550; letter-spacing: .2em; }
.stage-line { width: 26px; height: 1px; background: #65756c; }
.compatibility { display: flex; justify-content: space-between; align-items: center; gap: 32px; min-height: 104px; border-block: 1px solid var(--divider); }
.compatibility-label { color: var(--muted); font-size: 12px; }
.protocols { display: flex; align-items: center; gap: 24px; color: #bec6cb; font-size: 17px; letter-spacing: -.03em; }
.protocols strong { color: var(--ink); font-size: 23px; font-weight: 650; }
.protocol-divider { height: 24px; width: 1px; background: var(--divider); }
.protocol-dot { color: #59676b; }

h2 { font-size: clamp(32px, 3.1vw, 44px); letter-spacing: -.045em; font-weight: 650; line-height: 1.4; }
.section-intro { display: flex; justify-content: space-between; align-items: flex-end; gap: 48px; margin-bottom: 48px; }
.section-intro > p { max-width: 395px; color: var(--muted); font-size: 14px; line-height: 1.95; padding-bottom: 7px; }
.listening-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.listening-story { position: relative; min-width: 0; overflow: hidden; background: var(--surface); border: 1px solid rgba(170,178,185,.09); border-radius: 24px; }
.story-copy { position: relative; z-index: 2; padding: 34px 34px 24px; }
.story-icon { width: 42px; height: 42px; display: flex; align-items: center; justify-content: center; margin-bottom: 18px; border: 1px solid rgba(147,200,165,.2); border-radius: 12px; color: var(--accent-light); }
.story-copy h3 { font-size: 28px; letter-spacing: -.035em; line-height: 1.45; font-weight: 600; }
.story-copy p { max-width: 415px; color: var(--muted); font-size: 13px; line-height: 1.9; margin-top: 13px; }
.story-media { position: relative; display: flex; flex-direction: column; align-items: center; padding: 17px 28px 26px; }
.player-media { background: radial-gradient(ellipse at 50% 60%, rgba(59,130,88,.16), rgba(20,24,28,0) 70%); }
.lyrics-media { background: radial-gradient(ellipse at 50% 60%, rgba(85,111,96,.15), rgba(20,24,28,0) 70%); }
.story-phone { width: 232px; }
.story-phone:hover { transform: translateY(-4px); }
.image-hint { display: inline-flex; align-items: center; gap: 8px; margin-top: 22px; font-size: 10px; color: #9ca6ac; }
.image-hint .icon { width: 13px; height: 13px; }

.library-section { padding-top: 28px; }
.library-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 96px; align-items: center; }
.library-visual { min-height: 640px; position: relative; display: flex; flex-direction: column; align-items: center; justify-content: center; isolation: isolate; }
.library-orbit { position: absolute; width: 455px; max-width: 100%; height: 455px; border: 1px solid var(--divider); border-radius: 50%; z-index: -1; }
.library-orbit::before { content: ""; position: absolute; inset: 42px; border: 1px solid rgba(147,200,165,.07); border-radius: 50%; }
.library-orbit::after { content: ""; position: absolute; inset: 90px; border: 1px solid rgba(147,200,165,.06); border-radius: 50%; }
.library-phone { width: 252px; transform: rotate(-3deg); }
.library-phone:hover { transform: rotate(0); }
.library-caption { color: var(--muted); font-size: 11px; letter-spacing: .07em; margin-top: 29px; }
.library-copy h2 { font-size: clamp(29px, 2.85vw, 39px); }
.section-description { color: var(--muted); font-size: 14px; line-height: 1.95; margin-top: 22px; }
.feature-list { margin-top: 36px; }
.feature-row { display: flex; gap: 20px; border-top: 1px solid var(--divider); padding: 25px 0; }
.feature-row > .icon { width: 22px; height: 22px; margin-top: 2px; color: var(--accent-light); }
.feature-row h3 { font-size: 16px; font-weight: 600; }
.feature-row p { font-size: 12px; line-height: 1.9; margin-top: 8px; color: var(--muted); }
.feature-row:last-child { padding-bottom: 0; }
.details-section { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--divider); border-bottom: 1px solid var(--divider); padding-block: 44px; }
.detail-item { padding-inline: 32px; border-left: 1px solid var(--divider); }
.detail-item:first-child { padding-left: 0; border-left: 0; }
.detail-item:last-child { padding-right: 0; }
.detail-item > .icon { color: var(--accent-light); margin-bottom: 17px; }
.detail-item h3 { font-weight: 600; font-size: 17px; }
.detail-item p { color: var(--muted); font-size: 12px; line-height: 1.95; margin-top: 12px; max-width: 335px; }

.download-section { display: grid; grid-template-columns: 1fr 1fr; gap: 112px; padding-block: 112px 108px; }
.download-logo { width: 64px; height: 64px; border-radius: 19px; margin-bottom: 24px; }
.download-copy h2 { font-size: 46px; line-height: 1.3; }
.download-copy > p:first-of-type { font-size: 14px; color: var(--muted); line-height: 1.8; margin-top: 21px; margin-bottom: 28px; }
.download-copy .button { gap: 12px; min-height: 56px; padding-inline: 23px; }
.download-copy .button > .icon:last-child { margin-left: 12px; }
.release-link { display: flex; align-items: center; gap: 9px; font-size: 12px; color: #c4cdca; min-height: 48px; margin-top: 6px; width: fit-content; }
.release-link:hover { color: var(--accent-light); }
.platform-note { color: #8e999f; font-size: 10px; line-height: 1.95; margin-top: 9px; }
.getting-started { padding-top: 10px; align-self: center; }
.getting-started > h3 { font-size: 18px; font-weight: 600; margin-bottom: 22px; }
details { border-top: 1px solid var(--divider); }
details summary { min-height: 69px; display: flex; align-items: center; justify-content: space-between; gap: 18px; font-size: 13px; font-weight: 500; cursor: pointer; list-style: none; }
details summary::-webkit-details-marker { display: none; }
.details-plus { flex-shrink: 0; position: relative; width: 14px; height: 14px; color: #9ba8a0; }
.details-plus::before, .details-plus::after { content: ""; position: absolute; background: currentColor; top: 6px; left: 1px; width: 12px; height: 1px; }
.details-plus::after { transform: rotate(90deg); transition: transform 160ms ease-out; }
details[open] .details-plus::after { transform: rotate(0); }
details p { padding: 0 24px 24px 0; color: var(--muted); font-size: 12px; line-height: 1.95; }
details p a { color: var(--accent-light); text-decoration: underline; text-underline-offset: 3px; }
.guide-link { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 18px 20px; background: var(--surface); border: 1px solid var(--divider); border-radius: 12px; color: #c7d2cb; font-size: 12px; margin-top: 18px; transition: border-color 160ms ease-out; }
.guide-link:hover { border-color: var(--accent); }
.site-footer { border-top: 1px solid var(--divider); padding-top: 35px; padding-bottom: 28px; }
.footer-top { display: flex; align-items: center; gap: 24px; }
.footer-top .brand > img { width: 30px; height: 30px; border-radius: 9px; }
.footer-top .brand > span { font-size: 25px; }
.footer-top p { color: var(--muted); font-size: 11px; padding-top: 2px; }
.footer-github { display: inline-flex; align-items: center; gap: 8px; margin-left: auto; color: #c0c9ce; font-size: 12px; min-height: 48px; }
.footer-github:hover { color: var(--accent-light); }
.footer-github > .icon:first-child { width: 19px; height: 19px; }
.footer-bottom { display: flex; justify-content: space-between; gap: 24px; color: #89939b; font-size: 10px; margin-top: 30px; }
.footer-bottom a:hover { color: var(--ink); }

.screenshot-dialog { max-width: min(560px, calc(100vw - 32px)); max-height: calc(100dvh - 28px); border: 1px solid #3c4841; padding: 16px 22px 18px; border-radius: 24px; background: var(--surface); color: var(--ink); box-shadow: 0 24px 96px rgba(0,0,0,.5); }
.screenshot-dialog::backdrop { background: rgba(8,10,13,.92); }
.dialog-header { display: flex; align-items: center; justify-content: space-between; gap: 40px; font-size: 11px; color: var(--muted); margin-bottom: 12px; }
.dialog-close { display: flex; align-items: center; justify-content: center; width: 44px; height: 44px; background: var(--raised); border: 1px solid var(--divider); border-radius: 12px; }
.dialog-close:hover { border-color: var(--accent-light); }
.dialog-image { max-height: calc(100dvh - 176px); max-width: 100%; width: auto; height: auto; margin: auto; border-radius: 13px; object-fit: contain; }
#screenshot-caption { margin-top: 17px; color: #c0cbc4; font-size: 11px; text-align: center; line-height: 1.7; }

@media (min-width: 1500px) {
  .hero { min-height: 738px; }
  .hero-stage { transform: scale(1.04); transform-origin: 50% 50%; }
}

@media (max-width: 1150px) {
  .shell { width: calc(100% - 64px); }
  .hero { min-height: 650px; gap: 8px; }
  .hero-stage { height: 570px; }
  .phone-back { width: 196px; left: 19px; top: 74px; }
  .phone-front { width: 224px; right: 18px; top: 37px; }
  .sound-rings { width: 430px; height: 430px; top: 86px; }
  .hero-description { font-size: 14px; }
  .hero-actions { gap: 22px; }
  .hero-actions .button { padding-inline: 18px; }
  .library-layout { gap: 48px; }
  .download-section { gap: 70px; }
}

@media (max-width: 900px) {
  .main-nav { gap: 20px; }
  .hero { min-height: 610px; }
  h1 { font-size: 43px; }
  .hero-stage { height: 540px; }
  .phone-back { width: 167px; left: 8px; top: 84px; }
  .phone-front { width: 193px; right: 4px; top: 54px; }
  .sound-rings { width: 340px; height: 340px; top: 100px; }
  .hero-stage::before { width: 290px; }
  .stage-label { font-size: 7px; bottom: 38px; gap: 8px; }
  .hero-description { font-size: 13px; }
  .hero-actions { gap: 16px; flex-wrap: wrap; margin-top: 28px; }
  .hero-actions .button { font-size: 12px; padding-inline: 16px; }
  .hero-actions .text-link { font-size: 12px; gap: 7px; }
  .hero-note { font-size: 9px; gap: 9px; }
  .compatibility { flex-direction: column; justify-content: center; min-height: 122px; gap: 15px; }
  .section { padding-block: 86px; }
  .section-intro { align-items: start; gap: 30px; }
  .section-intro > p { max-width: 310px; font-size: 12px; padding-top: 8px; }
  .story-copy { padding-inline: 26px; }
  .story-copy h3 { font-size: 26px; }
  .story-copy p { font-size: 12px; }
  .story-phone { width: 214px; }
  .library-layout { gap: 38px; }
  .library-section { padding-top: 12px; }
  .library-phone { width: 224px; }
  .library-visual { min-height: 580px; }
  .library-orbit { height: 330px; width: 330px; }
  .library-copy h2 { font-size: 28px; }
  .section-description { font-size: 12px; }
  .feature-row { gap: 15px; padding-block: 20px; }
  .feature-row h3 { font-size: 14px; }
  .feature-row p { font-size: 11px; }
  .feature-list { margin-top: 27px; }
  .detail-item { padding-inline: 23px; }
  .detail-item h3 { font-size: 15px; }
  .detail-item p { font-size: 11px; }
  .download-section { gap: 44px; }
  .download-copy h2 { font-size: 40px; }
  .download-copy > p:first-of-type { font-size: 12px; }
  .getting-started > h3 { font-size: 16px; }
  .getting-started summary { font-size: 12px; }
}

@media (max-width: 700px) {
  html { scroll-padding-top: 28px; }
  .shell { width: calc(100% - 40px); }
  .section { padding-block: 68px; }
  .header-inner { min-height: 76px; }
  .brand > span { font-size: 27px; }
  .brand > img { width: 33px; height: 33px; }
  .menu-toggle { display: flex; }
  .main-nav { position: absolute; top: calc(100% - 1px); right: 20px; left: 20px; padding: 16px; background: var(--surface); border: 1px solid var(--divider); border-radius: 0 0 16px 16px; flex-direction: column; align-items: stretch; gap: 4px; box-shadow: 0 24px 35px rgba(0,0,0,.3); }
  .main-nav:not(.is-open) { display: none; }
  .main-nav > a { min-height: 48px; justify-content: flex-start; padding-inline: 14px; }
  .main-nav .nav-download { margin-top: 5px; padding-inline: 14px; }
  .hero { display: flex; flex-direction: column; align-items: stretch; gap: 0; padding-top: 42px; padding-bottom: 30px; min-height: 0; }
  .hero-copy { padding-bottom: 0; }
  .hero-kicker { font-size: 11px; gap: 10px; margin-bottom: 23px; }
  h1 { font-size: clamp(39px, 9vw, 60px); line-height: 1.32; letter-spacing: -.055em; }
  .hero-description { margin-top: 20px; font-size: 13px; line-height: 1.95; }
  .hero-actions { margin-top: 25px; gap: 25px; }
  .hero-actions .button { font-size: 13px; padding-inline: 18px; min-height: 52px; }
  .hero-actions .text-link { font-size: 13px; }
  .hero-note { font-size: 10px; margin-top: 21px; gap: 12px; }
  .hero-stage { height: 525px; width: 390px; max-width: 100%; margin: 32px auto 0; }
  .phone-back { width: 180px; left: 26px; top: 56px; }
  .phone-front { width: 205px; right: 24px; top: 19px; }
  .sound-rings { width: 350px; height: 350px; max-width: 103%; top: 68px; }
  .hero-stage::before { right: 18px; top: 20px; height: 420px; }
  .stage-label { font-size: 8px; bottom: 13px; }
  .compatibility { padding-block: 25px; gap: 18px; min-height: 0; }
  .compatibility-label { font-size: 10px; }
  .protocols { gap: 13px; font-size: 13px; }
  .protocols strong { font-size: 19px; }
  .protocol-divider { height: 18px; }
  h2 { font-size: 31px; }
  .section-intro { display: block; margin-bottom: 30px; }
  .section-intro > p { max-width: none; margin-top: 20px; font-size: 13px; padding: 0; }
  .listening-grid { grid-template-columns: 1fr; gap: 20px; }
  .story-copy { padding: 28px 27px 22px; }
  .story-copy h3 { font-size: 27px; }
  .story-copy p { font-size: 13px; line-height: 1.9; }
  .story-icon { margin-bottom: 17px; }
  .story-media { padding-top: 13px; padding-bottom: 25px; }
  .story-phone { width: 225px; }
  .image-hint { font-size: 10px; }
  .library-section { padding-top: 4px; }
  .library-layout { display: flex; flex-direction: column-reverse; gap: 42px; align-items: stretch; }
  .library-copy h2 { font-size: 30px; }
  .section-description { font-size: 13px; margin-top: 18px; }
  .feature-list { margin-top: 28px; }
  .feature-row { gap: 19px; padding-block: 23px; }
  .feature-row h3 { font-size: 15px; }
  .feature-row p { font-size: 12px; margin-top: 9px; }
  .library-visual { min-height: 0; padding-block: 10px; }
  .library-phone { width: 225px; }
  .library-orbit { width: 335px; max-width: 100%; height: auto; aspect-ratio: 1; }
  .library-caption { font-size: 11px; }
  .details-section { grid-template-columns: 1fr; padding-block: 8px; }
  .detail-item { display: grid; grid-template-columns: 24px 1fr; column-gap: 19px; padding: 27px 0; border-left: 0; border-top: 1px solid var(--divider); }
  .detail-item:first-child { border-top: 0; }
  .detail-item > .icon { margin-bottom: 0; margin-top: 1px; grid-row: 1 / 3; }
  .detail-item h3 { font-size: 15px; }
  .detail-item p { font-size: 12px; max-width: none; margin-top: 8px; }
  .download-section { grid-template-columns: 1fr; gap: 49px; padding-block: 66px; }
  .download-logo { width: 58px; height: 58px; border-radius: 17px; margin-bottom: 22px; }
  .download-copy h2 { font-size: 40px; }
  .download-copy > p:first-of-type { font-size: 13px; }
  .download-copy .button { font-size: 13px; }
  .platform-note { font-size: 11px; }
  .getting-started { padding-top: 0; }
  .getting-started > h3 { font-size: 18px; }
  .getting-started summary { font-size: 13px; }
  details p { font-size: 12px; }
  .guide-link { font-size: 12px; }
  .footer-top { gap: 14px; flex-wrap: wrap; }
  .footer-top p { flex-basis: calc(100% - 140px); font-size: 10px; }
  .footer-github { margin-left: 0; margin-top: 5px; font-size: 12px; }
  .footer-bottom { flex-direction: column; gap: 11px; margin-top: 17px; font-size: 9px; }
  .site-footer { padding-block: 27px; }
  .dialog-header { gap: 20px; }
}

@media (max-width: 370px) {
  .shell { width: calc(100% - 32px); }
  h1 { font-size: 36px; }
  .hero-actions { gap: 17px; }
  .hero-actions .button { font-size: 12px; padding-inline: 15px; }
  .hero-actions .text-link { font-size: 12px; }
  .hero-stage { height: 475px; }
  .phone-back { width: 159px; left: 19px; }
  .phone-front { width: 183px; right: 14px; }
  .stage-label { font-size: 7px; bottom: 9px; }
  .protocols { gap: 10px; font-size: 12px; }
  .protocols strong { font-size: 17px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

/* Shared language and accessibility refinements. */
:root { --accent: #34774e; }
html { scrollbar-color: #65756c var(--canvas); }
body { line-height: 1.6; }
h1, h2, h3 { text-wrap: balance; letter-spacing: -.04em; }
p, h1, h2, h3, a, summary { overflow-wrap: break-word; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
[tabindex="-1"]:focus { outline: none; }
.brand { min-height: 48px; }
.main-nav { gap: clamp(16px, 2.3vw, 34px); font-size: .875rem; }
.main-nav .language-link { color: var(--accent-light); min-width: 48px; text-decoration: underline; text-underline-offset: 5px; }
.hero-actions, .hero-note { flex-wrap: wrap; }
.hero-description, .section-intro > p, .story-copy p, .section-description,
.feature-row p, .detail-item p, .download-copy > p:first-of-type, details p { font-size: 1rem; }
.hero-kicker, .hero-note, .compatibility-label, .image-hint, .library-caption,
.release-link, .platform-note, .guide-link, .footer-top p, .footer-github,
.footer-bottom, #screenshot-caption, .dialog-status { font-size: .875rem; }
.hero-note { column-gap: 12px; row-gap: 4px; }
.hero-kicker { letter-spacing: .06em; }
.hero-actions .button, .hero-actions .text-link, .download-copy .button,
.getting-started summary { font-size: 1rem; }
.hero-actions .button, .download-copy .button { padding-block: 12px; }
.feature-row h3, .detail-item h3 { font-size: 1.125rem; }
.stage-label { color: #a2b0a8; font-size: .6875rem; letter-spacing: .12em; }
.hero-note, .platform-note, .footer-bottom { color: #a2adb5; }
.story-copy p { max-width: 48ch; }
.image-hint, .library-caption { text-align: center; }
.phone { max-width: 100%; }
.phone:focus-visible { outline: 3px solid var(--accent-light); outline-offset: 7px; z-index: 4; }
.button-primary:hover { background: #397f54; }
.button-primary:focus-visible { outline-color: var(--ink); }
.protocols { flex-wrap: wrap; justify-content: center; row-gap: 10px; }
.compatibility-label { text-align: center; }
.section-intro > *, .library-layout > *, .download-section > *, .feature-row > div { min-width: 0; }
.footer-bottom { align-items: center; }
.footer-bottom > a { display: inline-flex; align-items: center; min-height: 44px; }
.getting-started summary { padding-block: 18px; }
details p a { display: inline; text-decoration-thickness: 1px; }
details p a:hover { text-decoration-thickness: 2px; }
.screenshot-dialog { overflow: auto; }
.screenshot-dialog:not([open]) { display: none; }
.dialog-header h2 { font-size: 1rem; font-weight: 600; letter-spacing: 0; text-wrap: initial; }
.dialog-close { flex: 0 0 44px; }
.dialog-status { color: var(--accent-light); text-align: center; }
.dialog-status:not(:empty) { margin-top: 12px; }
html:lang(en) h1 { font-size: clamp(2.125rem, 4.5vw, 4rem); letter-spacing: -.04em; line-height: 1.2; }
html:lang(en) .hero-description { max-width: 48ch; }
html:lang(en) .hero-kicker { letter-spacing: .025em; }
html:lang(en) .section-intro > p { max-width: 41ch; }
html:lang(en) .story-copy h3 { line-height: 1.25; }
html:lang(en) .library-caption { letter-spacing: 0; }

@media (max-width: 900px) {
  /* Without JS the full menu remains visible in normal document flow. */
  .header-inner { flex-wrap: wrap; gap: 0 20px; padding-block: 14px; }
  .menu-toggle { display: none; }
  .main-nav, .main-nav:not(.is-open) { display: flex; position: static; width: 100%; flex-direction: column; align-items: stretch; padding: 12px 0 0; gap: 4px; background: transparent; border: 0; border-radius: 0; box-shadow: none; }
  .main-nav > a { min-height: 48px; justify-content: flex-start; padding-inline: 14px; }
  .main-nav .nav-download { padding-inline: 14px; margin-top: 5px; }
  .nav-enhanced .header-inner { flex-wrap: nowrap; }
  .nav-enhanced .menu-toggle { display: flex; flex: 0 0 48px; }
  .nav-enhanced .main-nav { position: absolute; inset: calc(100% - 1px) 20px auto; width: auto; padding: 16px; background: var(--surface); border: 1px solid var(--divider); border-radius: 0 0 16px 16px; box-shadow: 0 24px 35px rgba(0,0,0,.3); }
  .nav-enhanced .main-nav:not(.is-open) { display: none; }
  .section-intro { align-items: center; }
  .section-intro > p { max-width: 46%; }
  .hero-note .note-divider { display: none; }
  .hero-note > span { flex-basis: 100%; }
  .stage-label { font-size: .625rem; letter-spacing: .06em; gap: 8px; }
  .stage-line { width: 18px; }
}

@media (max-width: 700px) {
  .hero-description .desktop-break { display: none; }
  .hero-actions { gap: 12px 24px; }
  .hero-actions .button { padding-inline: 18px; }
  .hero-kicker { font-size: .875rem; }
  .hero-note { margin-top: 22px; }
  .hero-note > span { flex-basis: auto; }
  .section-intro > p { max-width: none; }
  .story-copy { padding-inline: 24px; }
  .story-copy h3 { font-size: 1.75rem; }
  .story-media { padding-inline: 24px; }
  .image-hint { gap: 6px; }
  .download-copy h2 { font-size: clamp(2rem, 9vw, 2.75rem); }
  .download-copy .button { padding-inline: 18px; gap: 8px; }
  .download-copy .button > .icon:last-child { margin-left: 0; }
  .footer-top p { flex-basis: 100%; }
  .footer-bottom { align-items: flex-start; gap: 4px; }
  .footer-bottom > a { padding-block: 10px; }
  html:lang(en) h1 { font-size: clamp(2.125rem, 8.5vw, 3.75rem); }
  .protocols { column-gap: 10px; font-size: .875rem; }
  .protocols strong { font-size: 1.125rem; }
  .compatibility { padding-inline: 0; }
  .screenshot-dialog { padding-inline: 14px; }
  .dialog-header { gap: 16px; }
}

@media (forced-colors: active) {
  .phone, .button, .main-nav .nav-download, .menu-toggle, .guide-link,
  .dialog-close, .listening-story, .screenshot-dialog { border-color: ButtonText; }
  a, .main-nav a, .main-nav .language-link { color: LinkText; }
  .button-primary, .skip-link { background: ButtonFace; color: ButtonText; border: 1px solid ButtonText; }
  :focus-visible, .button-primary:focus-visible, .phone:focus-visible { outline: 3px solid Highlight; }
  .sound-rings, .library-orbit, .hero-stage::before { display: none; }
  .details-plus { color: ButtonText; }
  .details-plus::before, .details-plus::after { forced-color-adjust: none; background: ButtonText; }
  .screenshot-dialog::backdrop { background: Canvas; opacity: .9; }
}

@media (prefers-reduced-motion: reduce) {
  .phone:hover, .button-primary:hover, .text-link:hover .icon { transform: none; }
  .phone-back, .phone-front, .library-phone, .hero-stage { transform: none; }
}