:root {
  color-scheme: light dark;
  --nn-bg: #f6f8fc;
  --nn-ink: #0b1b2e;
  --nn-muted: #52606d;
  --nn-line: #d9dee4;
  --nn-group: #f2f2f7;
  --nn-surface: #fff;
  --nn-blue: #3056d3;
  --nn-on-blue: #fff;
  --nn-blue-soft: #f2f7fe;
  --nn-green: #167143;
  --nn-note: #fff7e6;
  --nn-note-ink: #6b4300;
  --nn-radius: 14px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  background: var(--nn-bg);
  color: var(--nn-ink);
}
@media (prefers-color-scheme: dark) {
  :root {
    --nn-bg: #101419;
    --nn-ink: #eef3fa;
    --nn-muted: #b2bdcb;
    --nn-line: #475360;
    --nn-group: #1b232d;
    --nn-surface: #151d26;
    --nn-blue: #82b7ff;
    --nn-on-blue: #071a33;
    --nn-blue-soft: #182d49;
    --nn-green: #7bddaa;
    --nn-note: #352b18;
    --nn-note-ink: #f7d393;
  }
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; }
[hidden] { display: none !important; }
a { color: var(--nn-blue); text-underline-offset: .2em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
img, svg { max-width: 100%; }
h1, h2, h3, h4, p { margin: 0; }
h1 { font-size: clamp(1.9rem, 5vw, 2.8rem); line-height: 1.23; letter-spacing: -.035em; word-break: keep-all; overflow-wrap: anywhere; }
h2 { font-size: 1.3rem; line-height: 1.4; letter-spacing: -.02em; }
h3 { font-size: 1.1rem; line-height: 1.45; }
code { overflow-wrap: anywhere; }
:focus-visible { outline: 3px solid var(--nn-blue); outline-offset: 4px; }
.container { width: min(100% - 40px, 1000px); margin-inline: auto; }
.site-header { border-bottom: 1px solid var(--nn-line); }
.site-header .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 0 16px; padding-block: 12px; }
.logo { color: var(--nn-ink); font-size: 1.25rem; font-weight: 800; letter-spacing: -.035em; text-decoration: none; display: inline-flex; align-items: center; min-height: 48px; }
.logo b { color: var(--nn-blue); }
.header-links, .languages { display: flex; align-items: center; flex-wrap: wrap; gap: 0 14px; }
.header-links a, .languages a, .site-footer a { display: inline-flex; align-items: center; min-height: 48px; }
.languages { font-size: 1rem; }
.languages a[aria-current] { color: var(--nn-ink); font-weight: 700; text-decoration: none; }
main { padding-block: 36px 56px; }
.hero { display: grid; gap: 28px; }
.intro, .st, .stack { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.kicker { color: var(--nn-blue); font-weight: 650; }
.muted, .tiny, .m-p { color: var(--nn-muted); }
.tiny { font-size: 1rem; }
.device-grid, .dev { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.device-card, .dev > a { display: flex; flex-direction: column; gap: 6px; min-width: 0; padding: 18px 14px; border: 1px solid var(--nn-line); border-radius: var(--nn-radius); color: var(--nn-ink); background: var(--nn-surface); text-decoration: none; overflow-wrap: anywhere; }
.device-card strong, .dev > a b { font-size: 1.12rem; }
.device-card > span { color: var(--nn-muted); font-size: 1rem; }
.device-card:hover, .dev > a:hover { border-color: var(--nn-blue); }
.device-card.is-detected, .dev > a.hot { border-color: var(--nn-blue); box-shadow: inset 0 0 0 1px var(--nn-blue); background: var(--nn-blue-soft); }
.device-card .device-hint { color: var(--nn-blue); font-weight: 650; }
.btn { min-height: 52px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 18px; border: 1px solid transparent; border-radius: 13px; font-weight: 700; color: var(--nn-ink); background: var(--nn-group); text-align: center; text-decoration: none; line-height: 1.5; }
.btn.pri, .btn.primary { background: var(--nn-blue); color: var(--nn-on-blue); }
.btn.sec, .btn.secondary { background: var(--nn-group); border-color: var(--nn-line); }
.btn:hover { text-decoration: underline; }
.btn:disabled { opacity: .6; cursor: not-allowed; }
.card { border: 1px solid var(--nn-line); border-radius: var(--nn-radius); padding: 20px; display: flex; flex-direction: column; gap: 12px; background: var(--nn-surface); min-width: 0; }
.section { margin-top: 32px; }
.set { display: flex; flex-direction: column; gap: 6px; padding: 8px; border-radius: 12px; background: var(--nn-group); }
.set .row { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 12px; border-radius: 9px; background: var(--nn-surface); min-height: 52px; overflow-wrap: anywhere; }
.set .row em { font-style: normal; color: var(--nn-muted); }
.set .row.hl { outline: 2px solid var(--nn-blue); outline-offset: -2px; }
.prog { display: flex; gap: 4px; margin: 0; padding: 0; list-style: none; }
.prog > * { flex: 1; height: 5px; border-radius: 3px; background: var(--nn-line); }
.prog .on, .prog [aria-current="step"] { background: var(--nn-blue); }
.prog .done { background: var(--nn-green); }
.stepl { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; color: var(--nn-muted); }
.strow { display: flex; gap: 12px; align-items: center; padding: 12px; border-radius: 10px; background: var(--nn-group); }
.strow i { width: 28px; height: 28px; flex: none; display: grid; place-items: center; border-radius: 50%; font-style: normal; font-weight: 700; background: var(--nn-muted); color: var(--nn-bg); }
.strow.done i { background: var(--nn-green); }
.strow.now { outline: 2px solid var(--nn-blue); background: var(--nn-blue-soft); }
.strow.now i { background: var(--nn-blue); color: var(--nn-on-blue); }
.note { padding: 14px 16px; border-radius: 10px; color: var(--nn-note-ink); background: var(--nn-note); }
.resume { margin-bottom: 28px; background: var(--nn-blue-soft); }
[id^="step-"] { scroll-margin-top: 24px; }
.share { display: grid; gap: 12px; }
.share label { display: block; }
.share input { width: 100%; min-height: 52px; padding: 10px 12px; border: 1px solid var(--nn-line); border-radius: 8px; color: var(--nn-ink); background: var(--nn-bg); }
.site-footer { border-top: 1px solid var(--nn-line); padding-block: 20px; color: var(--nn-muted); }
.site-footer .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 24px; }
.skip-link { position: absolute; left: 20px; top: -100px; z-index: 10; padding: 12px; color: var(--nn-on-blue); background: var(--nn-blue); }
.skip-link:focus { top: 8px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
@media (min-width: 760px) {
  main { padding-block: 64px; }
  .hero { grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
  .intro { gap: 20px; }
  .device-card { padding: 22px 20px; }
  .section { margin-top: 40px; }
  .share { grid-template-columns: 1fr auto; align-items: end; }
  .share > p { grid-column: 1 / -1; }
  .guide { max-width: 740px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}


/* Shared landing-page chrome; guide copy and OS illustrations remain separate. */
:root[data-theme="light"] {
  color-scheme: light;
  --nn-bg: #f6f8fc;
  --nn-ink: #111827;
  --nn-muted: #536070;
  --nn-line: #d9e2ef;
  --nn-group: #eef2fa;
  --nn-surface: #fff;
  --nn-blue: #3056d3;
  --nn-on-blue: #fff;
  --nn-blue-soft: #edf1ff;
  --nn-green: #167143;
  --nn-note: #fff7e6;
  --nn-note-ink: #6b4300;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --nn-bg: #060608;
  --nn-ink: #fff;
  --nn-muted: #b2bdcb;
  --nn-line: #34343e;
  --nn-group: #17171f;
  --nn-surface: #101016;
  --nn-blue: #3056d3;
  --nn-on-blue: #fff;
  --nn-blue-soft: #182343;
  --nn-green: #7bddaa;
  --nn-note: #352b18;
  --nn-note-ink: #f7d393;
}
:root { --nn-radius: 16px; --nn-link: #3056d3; }
:root[data-theme="dark"] { --nn-link: #a7bcff; }
body { background: var(--nn-bg); color: var(--nn-ink); }
a { color: var(--nn-link); }
:focus-visible { outline-color: var(--nn-link); }
.container { width: min(100% - 40px, 1120px); }
h1 { font-size: clamp(32px, 4vw, 46px); font-weight: 800; }
.kicker { align-self: flex-start; color: var(--nn-link); padding: 6px 13px; border: 1px solid var(--nn-line); border-radius: 8px; background: var(--nn-blue-soft); font-size: 16px; }
main { padding-block: 48px 72px; }
.guide { max-width: 820px; }
.hero { gap: 36px; }
.intro { gap: 22px; }
.btn { border-radius: 8px; padding-inline: 22px; }
.btn.pri:hover, .btn.primary:hover { background: #2443a8; text-decoration: none; }
.btn.sec:hover, .btn.secondary:hover { border-color: var(--nn-link); text-decoration: none; }
.card { padding: 26px; box-shadow: 0 8px 26px rgba(0,0,0,.035); }
.device-grid { gap: 16px; }
.device-card { padding: 24px 20px; gap: 12px; box-shadow: 0 8px 24px rgba(0,0,0,.035); }
.device-card strong { font-size: 23px; }
.device-card.is-detected { background: var(--nn-surface); }
.device-card .device-hint { color: var(--nn-link); }
.nn-step { border: 1px solid var(--nn-line); border-radius: var(--nn-radius); padding: 28px; background: var(--nn-surface); }
.nn-step h2 { font-size: 25px; }
.nn-steps { padding: 16px 0 !important; border-block: 1px solid var(--nn-line); }
.nn-steps a { font-weight: 600; }
.stepl { font-size: 16px; }
.prog { gap: 6px; }
.prog > * { height: 6px; }
.section { margin-top: 40px; }
.nn-preview { --nn-group: #f2f2f7; --nn-surface: #fff; }
:root[data-theme="dark"] .nn-preview { --nn-group: #1c1c1e; --nn-surface: #2c2c2e; }
.nn-preview .set { border: 1px solid var(--nn-line); padding: 10px; }
.site-header { background: var(--nn-surface); position: relative; z-index: 5; }
.site-header .header-layout { display: grid; grid-template-columns: auto minmax(0,1fr) auto auto; grid-template-areas: "logo menu theme languages"; gap: 16px; padding-block: 18px; }
.logo { grid-area: logo; min-height: 48px; }
.logo img { width: 118px; height: auto; }
.logo-on-dark { display: none; }
:root[data-theme="dark"] .logo-on-dark { display: block; }
:root[data-theme="dark"] .logo-on-light { display: none; }
.languages { grid-area: languages; flex-wrap: nowrap; gap: 2px; }
.languages a { font-size: 14px; padding-inline: 7px; text-decoration: none; border-radius: 8px; }
.languages a[aria-current] { background: var(--nn-blue-soft); color: var(--nn-link); }
.theme-switch { grid-area: theme; display: inline-flex; padding: 3px; gap: 2px; border: 1px solid var(--nn-line); border-radius: 28px; background: var(--nn-group); }
.theme-switch button { width: 34px; min-height: 48px; padding: 0; border: 0; border-radius: 24px; color: var(--nn-muted); background: transparent; font-size: 23px; line-height: 1; }
.theme-switch [aria-pressed="true"] { background: var(--nn-blue); color: #fff; }
:root[data-theme="dark"] .theme-switch [aria-pressed="true"] { background: #fff; color: #111827; }
.site-menu { grid-area: menu; min-width: 0; }
.site-menu > summary { display: none; }
.menu-panel { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.primary-links, .account-links { display: flex; align-items: center; gap: 16px; }
.primary-links a, .header-login { display: inline-flex; align-items: center; min-height: 48px; color: var(--nn-ink); font-size: 14px; text-decoration: none; white-space: nowrap; }
.primary-links a:hover, .header-login:hover { color: var(--nn-link); text-decoration: underline; }
.account-links { gap: 10px; }
.header-start { background: #22c55e; color: #052e16; font-weight: 700; font-size: 14px; white-space: nowrap; min-height: 48px; padding: 10px 14px; }
.header-start:is(:hover, :focus, :focus-visible) { background: #22c55e; color: #052e16; text-decoration: none; }
.site-footer { background: var(--nn-surface); padding-block: 44px; }
.site-footer .footer-layout { align-items: flex-start; gap: 32px; }
.footer-brand { display: grid; gap: 16px; max-width: 340px; font-size: 16px; }
.footer-brand .logo { grid-area: auto; justify-self: start; }
.nn-footer-links { display: flex; flex-wrap: wrap; gap: 0 20px; max-width: 580px; }
.nn-footer-links a { font-size: 16px; color: var(--nn-muted); text-decoration: none; }
.nn-footer-links a:hover { color: var(--nn-link); text-decoration: underline; }
body .nn-contact { min-height: 48px; }
@media (max-width: 1100px) {
  .site-header .header-layout { grid-template-columns: minmax(0,1fr) auto auto; grid-template-areas: "logo theme menu" "languages languages languages"; gap: 4px 12px; padding-block: 10px; }
  .languages { justify-content: center; }
  .languages a { padding-inline: 16px; font-size: 16px; }
  .site-menu > summary { display: flex; align-items: center; justify-content: center; width: 48px; min-height: 48px; padding: 0; font-size: 26px; border-radius: 8px; border: 1px solid var(--nn-line); list-style: none; cursor: pointer; }
  .site-menu > summary::-webkit-details-marker { display: none; }
  .menu-panel { position: absolute; inset: 100% 20px auto; display: grid; padding: 18px 22px; border: 1px solid var(--nn-line); border-radius: 12px; background: var(--nn-surface); box-shadow: 0 16px 32px rgba(0,0,0,.16); }
  .primary-links { display: grid; gap: 0; }
  .primary-links a { font-size: 16px; border-bottom: 1px solid var(--nn-line); }
  .account-links { display: grid; grid-template-columns: 1fr 1fr; }
  .header-login { font-size: 16px; justify-content: center; }
  .header-start { font-size: 16px; }
}
@media (max-width: 759px) {
  main { padding-block: 32px 56px; }
  .hero { gap: 28px; }
  .card, .nn-step { padding: 20px; }
  .nn-step h2 { font-size: 23px; }
  .section { margin-top: 32px; }
  .site-footer { padding-bottom: 100px; }
}
@media (max-width: 399px) {
  .logo img { width: 100px; }
  .device-grid { grid-template-columns: 1fr; }
}

.nn-q2 .nn-steps { display: flex; flex-wrap: wrap; gap: 4px 12px; margin: 0; list-style: none; }
.nn-q2 .nn-steps a { display: inline-flex; align-items: center; min-width: 44px; min-height: 48px; }
.nn-q2 .nn-step { margin-top: 12px; padding: 24px; }
.nn-q2 .nn-q2-action { line-height: 1.6; word-break: normal; overflow-wrap: anywhere; }
.nn-q2 .nn-q2-number { color: var(--nn-muted); font-weight: 700; font-size: 14px; }
.nn-q2 .tiny { font-size: 14px; line-height: 1.6; }
.nn-q2 .nn-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.nn-q2 .nn-actions .btn { flex: 1; min-width: 120px; }
.nn-q2 .nn-q2-details { border: 1px solid var(--nn-line); border-radius: 12px; background: var(--nn-surface); padding: 0 16px; }
.nn-q2 .nn-q2-details > summary { min-height: 48px; padding: 12px 0; cursor: pointer; font-weight: 600; line-height: 1.5; overflow-wrap: anywhere; }
.nn-q2 .nn-q2-details > .stack { padding: 4px 0 16px; }
.nn-q2 .nn-q2-details:not([open]) > .stack { display: none; }
.nn-q2 .nn-table { width: 100%; border-collapse: collapse; table-layout: fixed; }
.nn-q2 .nn-table th, .nn-q2 .nn-table td { padding: 12px 8px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--nn-line); overflow-wrap: anywhere; }
.nn-q2 .nn-table caption { text-align: left; color: var(--nn-muted); padding-bottom: 12px; }
.nn-q2 .theme-switch button { width: 44px; }
.nn-q2 .languages a { min-width: 44px; }
.nn-q2 main a:not(.btn):not(.device-card) { display: inline-flex; align-items: center; min-height: 44px; }
.nn-q2 .device-card.is-detected { border-color: var(--nn-line); box-shadow: none; background: var(--nn-blue-soft); }
.nn-q2 .device-card:hover { border-color: var(--nn-line); }
@media (max-width: 759px) {
  .nn-q2 .nn-step { padding: 18px; }
  .nn-q2 .nn-contact { position: static; width: max-content; margin: 12px 16px 16px auto; }
  .nn-q2 .site-header .header-layout { gap: 4px 8px; }
  .nn-q2 .theme-switch { padding: 2px; gap: 0; }
  .nn-q2 .nn-error-table thead { display: none; }
  .nn-q2 .nn-error-table tr { display: block; padding: 10px 0; }
  .nn-q2 .nn-error-table th, .nn-q2 .nn-error-table td { display: block; width: auto; padding: 4px 0; border: 0; }
}

/* Faint 64px grid at the top of the page, fading out (same as home hero). */
body { position: relative; isolation: isolate; }
body::before { content: ""; position: absolute; inset: 0 0 auto 0; height: 640px; z-index: -1; pointer-events: none;
  background-image: linear-gradient(to right, rgba(9,9,11,.05) 1px, transparent 1px), linear-gradient(rgba(9,9,11,.05) 1px, transparent 1px);
  background-size: 64px 64px; -webkit-mask-image: linear-gradient(#000 0%, transparent 100%); mask-image: linear-gradient(#000 0%, transparent 100%); }
html[data-theme="dark"] body::before { background-image: linear-gradient(to right, rgba(255,255,255,.1) 1px, transparent 1px), linear-gradient(rgba(255,255,255,.1) 1px, transparent 1px); }