/* VnKey's introduction page: shared by index.html (Vietnamese) and en/index.html. */
:root {
  --paper: #FBF7F2;
  --paper-2: #F4EDE4;
  --card: #FFFFFF;
  --ink: #1D1815;
  --ink-2: #5E544C;
  --ink-3: #8A7F76;
  --line: #E7DCCF;
  --red: #C8102E;
  --red-hi: #FF5640;
  --red-text: #B00E28;
  --gold: #F29F05;
  --gold-text: #9A6200;
  --kbd-bg: #FFFFFF;
  --kbd-edge: #D9CCBD;
  --shadow: 0 1px 2px rgba(60, 30, 10, .06), 0 8px 24px -12px rgba(60, 30, 10, .18);
  --radius: 16px;
  --sans: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #15110F;
    --paper-2: #1C1714;
    --card: #211B18;
    --ink: #F4ECE3;
    --ink-2: #BDB0A4;
    --ink-3: #8C8077;
    --line: #342B26;
    --red-text: #FF7A66;
    --gold-text: #F5B23A;
    --kbd-bg: #2B2420;
    --kbd-edge: #120E0C;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 30px -14px rgba(0, 0, 0, .7);
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--red-text); text-underline-offset: .18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--red-hi); outline-offset: 3px; border-radius: 4px; }
code, kbd, pre { font-family: var(--mono); }
code { font-size: .88em; padding: .1em .35em; border-radius: 6px; background: var(--paper-2); border: 1px solid var(--line); white-space: nowrap; }
.wrap { width: min(1120px, 100% - 32px); margin-inline: auto; }
.vh { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* Header */
.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 70%, transparent);
}
.top .wrap { display: flex; align-items: center; gap: 24px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 800; font-size: 19px; letter-spacing: -.01em; }
.brand img { width: 30px; height: 30px; }
.top nav { display: flex; gap: 22px; margin-left: auto; font-size: 15px; font-weight: 500; }
.top nav a { color: var(--ink-2); text-decoration: none; }
.top nav a:hover { color: var(--ink); }
@media (max-width: 720px) { .top nav a:not(.gh) { display: none; } }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  min-height: 48px; padding: 0 22px; border-radius: 999px;
  font: 600 16px/1 var(--sans); text-decoration: none; white-space: nowrap;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn svg { width: 18px; height: 18px; flex: none; }
.btn-primary { background: var(--red); color: #fff; box-shadow: 0 6px 18px -6px rgba(200, 16, 46, .55); }
.btn-primary:hover { background: #B30D28; transform: translateY(-1px); text-decoration: none; }
.btn-ghost { color: var(--ink); border: 1px solid var(--line); background: var(--card); }
.btn-ghost:hover { border-color: var(--ink-3); text-decoration: none; }

/* Hero */
.hero { padding: 56px 0 72px; overflow: hidden; }
.hero .wrap { display: grid; grid-template-columns: 1.08fr .92fr; gap: 48px; align-items: center; }
@media (max-width: 900px) { .hero .wrap { grid-template-columns: 1fr; gap: 40px; } .hero { padding-top: 36px; } }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 600; color: var(--ink-2);
  padding: 6px 12px 6px 8px; border-radius: 999px; background: var(--card); border: 1px solid var(--line);
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--gold); box-shadow: 0 0 0 3px color-mix(in srgb, var(--gold) 25%, transparent); }
h1 {
  margin: 20px 0 18px;
  font-size: clamp(38px, 5.6vw, 64px); line-height: 1.12; letter-spacing: -.03em; font-weight: 800;
  text-wrap: balance;
}
h1 .hl { color: var(--red-text); }
.lede { font-size: clamp(17px, 1.6vw, 20px); color: var(--ink-2); max-width: 34em; margin: 0 0 28px; text-wrap: pretty; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.meta { margin: 18px 0 0; font-size: 14px; color: var(--ink-3); }
.meta a { color: inherit; white-space: nowrap; }

/* The phone */
.device { position: relative; justify-self: center; width: min(340px, 100%); }
.device::before {
  content: ""; position: absolute; inset: 8% -30% 4%; z-index: -1;
  background: radial-gradient(closest-side, color-mix(in srgb, var(--red-hi) 22%, transparent), transparent);
  filter: blur(10px);
}
.phone {
  padding: 18px 14px 20px;
  border-radius: 30px 30px 40px 40px;
  background: linear-gradient(165deg, #61656b 0%, #34373b 30%, #1d1f22 70%, #2a2c30 100%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, .28),
    inset 0 0 0 1px rgba(255, 255, 255, .07),
    inset 0 -2px 6px rgba(0, 0, 0, .5),
    0 40px 60px -30px rgba(50, 10, 10, .55),
    0 14px 28px -14px rgba(0, 0, 0, .45);
}
.earpiece { width: 58px; height: 5px; margin: 0 auto 12px; border-radius: 3px; background: #0b0c0d; box-shadow: inset 0 1px 2px #000, 0 1px 0 rgba(255, 255, 255, .1); }
.bezel { padding: 7px; border-radius: 8px; background: #060607; box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .06); }
.screen {
  container-type: inline-size;
  aspect-ratio: 4 / 3; overflow: hidden; border-radius: 2px; background: #000;
}
.s60 {
  height: 100%; display: flex; flex-direction: column;
  font: 500 calc(100cqw / 320 * 14) / 1.3 var(--sans);
  color: #fff;
}
.s60 .sp, .s60 .cp {
  display: flex; align-items: center; gap: .45em; padding: 0 .5em; flex: none;
  background: linear-gradient(#2a508f, #142b55);
  box-shadow: inset 0 -1px 0 rgba(255, 255, 255, .12);
}
.s60 .sp { height: 2.05em; }
.s60 .cp { height: 1.95em; background: linear-gradient(#183463, #0c1b38); box-shadow: inset 0 1px 0 rgba(255, 255, 255, .14); justify-content: space-between; font-weight: 600; }
.s60 .sig, .s60 .bat { display: flex; align-items: flex-end; gap: .1em; height: 1em; }
.s60 .sig i, .s60 .bat i { width: .2em; background: #fff; border-radius: .04em; }
.s60 .sig i:nth-child(1) { height: 30%; } .s60 .sig i:nth-child(2) { height: 48%; }
.s60 .sig i:nth-child(3) { height: 66%; } .s60 .sig i:nth-child(4) { height: 83%; }
.s60 .sig i:nth-child(5) { height: 100%; }
.s60 .bat { margin-left: auto; align-items: center; }
.s60 .bat i { height: .95em; width: .26em; }
.s60 .bat b { width: .14em; height: .45em; background: #fff; border-radius: 0 .05em .05em 0; }
.s60 .title { font-weight: 700; font-size: .95em; letter-spacing: .01em; }
.s60 .ed { flex: 1; min-height: 0; padding: .45em .6em; background: linear-gradient(#ffffff, #eef2f8); color: #12161d; display: flex; flex-direction: column; gap: .4em; }
.s60 .to { display: flex; gap: .45em; padding: .12em .45em; font-size: .86em; color: #31466b; background: #fff; border: 1px solid #a9bbd6; border-radius: .25em; }
.s60 .to b { font-weight: 600; color: #12161d; }
.s60 .msg { font-size: 1.02em; line-height: 1.42; overflow-wrap: anywhere; transition: opacity .35s ease, transform .35s ease; }
.s60 .msg.away { opacity: 0; transform: translateY(-.6em); }
.s60 .caret { display: inline-block; width: .09em; min-width: 1px; height: 1.15em; margin-left: .03em; vertical-align: -.22em; background: #1b4fa8; animation: blink 1.05s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.s60 .mid { display: flex; align-items: center; gap: .4em; font-weight: 500; font-size: .92em; }
.s60 .mid svg { width: calc(100cqw / 320 * 13); height: auto; }
.s60 .wlan { width: calc(100cqw / 320 * 12) !important; }

.navkeys { display: grid; grid-template-columns: 1fr 1fr auto 1fr 1fr; align-items: center; gap: 8px; padding: 14px 4px 12px; }
.nk { height: 13px; border-radius: 7px; background: linear-gradient(#3f4247, #222428); box-shadow: inset 0 1px 0 rgba(255, 255, 255, .13), 0 1px 1px rgba(0, 0, 0, .6); position: relative; }
.nk.call::after, .nk.end::after { content: ""; position: absolute; left: 50%; top: 50%; width: 12px; height: 3px; margin: -1.5px 0 0 -6px; border-radius: 2px; }
.nk.call::after { background: #3fbf5f; }
.nk.end::after { background: #e5484d; }
.dpad { width: 50px; height: 50px; border-radius: 50%; background: radial-gradient(circle at 50% 35%, #50545a, #232528 72%); box-shadow: inset 0 1px 0 rgba(255, 255, 255, .18), 0 2px 4px rgba(0, 0, 0, .55); display: grid; place-items: center; }
.dpad::after { content: ""; width: 20px; height: 20px; border-radius: 50%; background: radial-gradient(circle at 40% 35%, #a9adb3, #5d6167 70%); box-shadow: 0 1px 2px rgba(0, 0, 0, .6); }

.kb { display: grid; grid-template-columns: repeat(10, 1fr); gap: 5px 4px; }
.key {
  position: relative; height: 25px; border-radius: 5px 5px 8px 8px;
  display: grid; place-items: center;
  font: 600 10.5px/1 var(--sans); color: #ECEDEF; text-transform: uppercase;
  background: linear-gradient(#383b40, #1e2023);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .14), 0 1px 0 rgba(0, 0, 0, .7);
  transition: background .18s ease, color .18s ease, box-shadow .18s ease, transform .08s ease;
}
.key sup { position: absolute; top: 2px; right: 3px; font-size: 7px; font-weight: 700; color: #F5B23A; }
.key.mod { font-size: 8px; color: #B7BBC1; text-transform: none; letter-spacing: .02em; }
.key.space { grid-column: span 4; }
.key.on {
  background: linear-gradient(#ff6a52, #c8102e); color: #fff; transform: translateY(1px);
  box-shadow: 0 0 0 1px rgba(255, 106, 82, .55), 0 0 16px rgba(255, 86, 64, .65);
  transition-duration: .04s;
}
.key.on sup { color: #fff; }

.demo-cap {
  display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 10px;
  margin: 22px auto 0; font-size: 15px; color: var(--ink-2); min-height: 36px;
}
.demo-cap .lbl { font-size: 12px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); }
.demo-cap kbd, .demo-cap .out {
  display: inline-block; min-width: 4.5em; padding: 5px 12px; border-radius: 9px; text-align: center;
  font-size: 16px; font-weight: 700;
}
.demo-cap kbd { font-family: var(--mono); background: var(--kbd-bg); color: var(--ink); border: 1px solid var(--line); box-shadow: 0 2px 0 var(--kbd-edge); }
.demo-cap .out { font-family: var(--sans); background: var(--red); color: #fff; }
.demo-cap .arrow { color: var(--ink-3); }

/* Sections */
section { padding: 84px 0; }
section.alt { background: var(--paper-2); border-block: 1px solid var(--line); }
.kicker { font-size: 13px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--red-text); margin: 0 0 10px; }
h2 { font-size: clamp(28px, 3.6vw, 42px); line-height: 1.18; letter-spacing: -.025em; font-weight: 800; margin: 0 0 14px; text-wrap: balance; }
.sub { color: var(--ink-2); max-width: 40em; margin: 0 0 40px; font-size: 18px; text-wrap: pretty; }
h3 { font-size: 19px; line-height: 1.3; letter-spacing: -.01em; margin: 0 0 8px; font-weight: 700; }

.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 960px) { .grid3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 620px) { .grid3 { grid-template-columns: 1fr; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.card p { margin: 0; color: var(--ink-2); font-size: 16px; }
.sample {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  margin: 0 0 18px; min-height: 40px;
}
.sample .to { color: var(--ink-3); }
.sample .res { font-weight: 700; font-size: 19px; }
.sample .mk { display: inline-flex; padding: 3px; border-radius: 6px; background: #142b55; }
.sample .mk svg { width: 20px; height: auto; }
.sample .tag { font-size: 12px; font-weight: 600; color: var(--ink-3); }

kbd.k {
  display: inline-block; min-width: 1.9em; padding: 3px 8px; border-radius: 7px; text-align: center;
  font: 700 15px/1.3 var(--mono); color: var(--ink);
  background: var(--kbd-bg); border: 1px solid var(--line); box-shadow: 0 2px 0 var(--kbd-edge);
}

/* How it works */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; counter-reset: s; margin: 0; padding: 0; list-style: none; }
@media (max-width: 820px) { .steps { grid-template-columns: 1fr; } }
.steps li { position: relative; padding: 22px 22px 22px 66px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); color: var(--ink-2); font-size: 16px; }
.steps li::before {
  counter-increment: s; content: counter(s);
  position: absolute; left: 20px; top: 20px; width: 32px; height: 32px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 800; font-size: 15px; color: #fff; background: var(--red);
}
.steps strong { display: block; color: var(--ink); font-size: 17px; margin-bottom: 4px; }

/* Telex */
.telex { display: grid; grid-template-columns: 1fr 1fr 1.15fr; gap: 18px; align-items: start; }
@media (max-width: 960px) { .telex { grid-template-columns: 1fr 1fr; } .telex .tricks { grid-column: 1 / -1; } }
@media (max-width: 620px) { .telex { grid-template-columns: 1fr; } }
.tbl { width: 100%; border-collapse: collapse; font-size: 16px; }
.tbl th { text-align: left; font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); padding: 0 0 10px; }
.tbl td { padding: 7px 0; border-top: 1px solid var(--line); vertical-align: middle; }
.tbl td:last-child { text-align: right; color: var(--ink-3); font-size: 14px; }
.tbl .r { font-weight: 700; font-size: 20px; padding-left: 10px; }
.tbl .r::before { content: "→"; color: var(--ink-3); font-weight: 400; font-size: 15px; margin-right: 10px; }
.note { margin: 26px 0 0; font-size: 14px; color: var(--ink-3); }

/* Install */
.install { display: grid; grid-template-columns: 1.15fr .85fr; gap: 28px; align-items: start; }
@media (max-width: 900px) { .install { grid-template-columns: 1fr; } }
.req { border-left: 4px solid var(--gold); }
.req ul, .good ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 14px; }
.req li, .good li { color: var(--ink-2); font-size: 16px; }
.req li strong, .good li strong { color: var(--ink); }
.howto { margin: 0; padding: 0; list-style: none; counter-reset: i; display: grid; gap: 4px; }
.howto li { position: relative; padding: 16px 0 16px 52px; border-top: 1px solid var(--line); color: var(--ink-2); }
.howto li:first-child { border-top: 0; padding-top: 4px; }
.howto li:first-child::before { top: 4px; }
.howto li::before {
  counter-increment: i; content: counter(i);
  position: absolute; left: 0; top: 16px; width: 34px; height: 34px; border-radius: 10px;
  display: grid; place-items: center; font-weight: 800; color: var(--red-text);
  background: color-mix(in srgb, var(--red) 10%, var(--card)); border: 1px solid color-mix(in srgb, var(--red) 25%, var(--line));
}
.howto strong { color: var(--ink); }
.vi { font-style: normal; font-weight: 600; color: var(--ink); }
.good { margin-top: 18px; }

/* Build */
.build { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; align-items: center; }
@media (max-width: 900px) { .build { grid-template-columns: 1fr; } }
pre {
  margin: 0; padding: 20px 22px; overflow-x: auto; border-radius: var(--radius);
  background: #17120F; color: #EDE5DB; font-size: 14px; line-height: 1.7;
  border: 1px solid #2E2622; box-shadow: var(--shadow);
}
pre code { padding: 0; border: 0; border-radius: 0; background: none; color: inherit; font-size: inherit; white-space: pre; }
pre .c { color: #8C7F75; }
pre .p { color: var(--red-hi); user-select: none; }
.build p { color: var(--ink-2); margin: 0 0 14px; }

/* Footer */
footer { padding: 40px 0 56px; color: var(--ink-3); font-size: 14px; border-top: 1px solid var(--line); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 28px; justify-content: space-between; align-items: center; }
footer .brand { font-size: 16px; }
footer .brand img { width: 24px; height: 24px; }
footer p { margin: 0; max-width: 46em; }

@media (max-width: 520px) {
  body { font-size: 16px; }
  section { padding: 64px 0; }
  .btn { width: 100%; justify-content: center; }
  .card { padding: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  .s60 .caret { animation: none; }
  .btn, .key, .s60 .msg { transition: none; }
}

/* Language switch */
.lang { display: inline-flex; flex: none; padding: 3px; border: 1px solid var(--line); border-radius: 999px; background: var(--card); font-size: 13px; font-weight: 700; line-height: 1; }
.lang a { padding: 6px 10px; border-radius: 999px; color: var(--ink-2); text-decoration: none; }
.lang a:hover { color: var(--ink); }
.lang a[aria-current] { background: var(--ink); color: var(--paper); }