/* Kn°End project site: the web app's look (web/style.css), a field manual for a small instrument.
   Warm graphite or paper, hairline rules, numbered sections, mono labels, one signal colour. */

:root {
  --bg: #f2efe8; --raise: #fbf9f4; --text: #171513; --muted: #6f6a62; --faint: #a8a296;
  --line: #d9d3c6; --ink: #171513; --ink-text: #fbf9f4;
  --signal: #ff5a1f; --signal-soft: rgb(255 90 31 / .12); --ok: #2f8f5b;
  --key: #2a2f33; --key-text: #ece8df;
  --sans: "Instrument Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --ease: cubic-bezier(.2, .7, .2, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d0e0f; --raise: #141617; --text: #ece8df; --muted: #8d897f; --faint: #57544d;
    --line: #26292b; --ink: #ece8df; --ink-text: #0d0e0f;
    --signal: #ff6a33; --signal-soft: rgb(255 106 51 / .14); --ok: #63d38f;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0d0e0f; --raise: #141617; --text: #ece8df; --muted: #8d897f; --faint: #57544d;
  --line: #26292b; --ink: #ece8df; --ink-text: #0d0e0f;
  --signal: #ff6a33; --signal-soft: rgb(255 106 51 / .14); --ok: #63d38f;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.6 var(--sans); -webkit-font-smoothing: antialiased; overflow-x: hidden;
}
body::before {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px; opacity: .28;
  mask-image: radial-gradient(ellipse at 50% 0%, #000 0%, transparent 70%);
}
a { color: var(--text); text-decoration-color: var(--signal); text-underline-offset: 3px; }
::selection { background: var(--signal); color: #fff; }
:focus-visible { outline: 2px solid var(--signal); outline-offset: 2px; border-radius: 6px; }
code { font: .88em var(--mono); background: var(--raise); border: 1px solid var(--line); border-radius: 6px; padding: 1px 5px; }
.muted { color: var(--muted); }
.small { font-size: 13px; font-weight: 400; }

/* ---- header ---- */
.top {
  position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 24px;
  padding: 14px clamp(16px, 4vw, 40px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(1.2); border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.word { font-weight: 600; font-size: 21px; letter-spacing: -.03em; display: inline-flex; align-items: flex-start; }
.degree {
  width: .36em; height: .36em; margin: .14em .06em 0 .04em; border-radius: 50%;
  border: .085em solid var(--signal); background: var(--signal);
  box-shadow: 0 0 0 4px var(--signal-soft), 0 0 14px var(--signal);
}
.loop { width: 46px; height: 16px; overflow: visible; }
.loop path { fill: none; stroke: var(--signal); stroke-width: 1.4; stroke-linecap: round;
  stroke-dasharray: 60 260; animation: no-end 7s linear infinite; }
@keyframes no-end { to { stroke-dashoffset: -320; } }
.tabs { display: flex; gap: 2px; padding: 3px; border: 1px solid var(--line); border-radius: 999px; background: var(--raise); margin-left: auto; }
.tabs a { color: var(--muted); font: 500 14px/1 var(--sans); padding: 8px 14px; border-radius: 999px; text-decoration: none; transition: color .2s, background .25s var(--ease); }
.tabs a:hover { color: var(--ink-text); background: var(--ink); }
.scheme { display: flex; border: 1px solid var(--line); border-radius: 999px; padding: 2px; }
.scheme button { border: 0; background: none; color: var(--faint); font: 500 10px/1 var(--mono); letter-spacing: .08em;
  text-transform: uppercase; padding: 6px 9px; border-radius: 999px; cursor: pointer; }
.scheme button:hover { color: var(--text); }
.scheme button[aria-pressed="true"] { color: var(--text); background: var(--line); }
@media (max-width: 900px) { .tabs { display: none; } .scheme { margin-left: auto; } }

/* ---- page ---- */
main { max-width: 1120px; margin: 0 auto; padding: clamp(24px, 5vw, 56px) clamp(16px, 4vw, 40px) 80px; counter-reset: section; }
.card { padding: 28px 0 40px; border-top: 1px solid var(--line); min-width: 0; }
.card h2 {
  counter-increment: section; display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap;
  margin: 0 0 22px; font: 600 clamp(20px, 2.4vw, 26px)/1.25 var(--sans); letter-spacing: -.02em;
}
.card h2::before { content: counter(section, decimal-leading-zero); font: 500 12px/1 var(--mono); color: var(--signal); letter-spacing: .06em; }
h3 { font: 600 16px/1.3 var(--sans); margin: 0 0 6px; letter-spacing: -.01em; }
p { margin: 0 0 12px; }

/* ---- hero ---- */
.hero { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); align-items: center;
  gap: clamp(28px, 5vw, 72px); padding: 0 0 clamp(40px, 6vw, 72px); }
@media (max-width: 800px) { .hero { grid-template-columns: 1fr; } }
.kicker { font: 500 11px/1.4 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--signal); margin: 0 0 18px; }
h1 { font-size: clamp(40px, 6.4vw, 76px); font-weight: 600; letter-spacing: -.045em; line-height: 1; margin: 0 0 22px; }
.lede { font-size: clamp(17px, 1.6vw, 19px); color: var(--muted); max-width: 34em; }
.said { font: 12px/1.5 var(--mono); color: var(--faint); margin-top: 18px; }
.actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 26px; }
.button { display: inline-block; font: 500 15px/1 var(--sans); padding: 13px 20px; border-radius: 999px; text-decoration: none;
  border: 1px solid transparent; transition: transform .15s var(--ease), border-color .2s; }
.button.primary { background: var(--ink); color: var(--ink-text); }
.button.primary:hover { transform: translateY(-1px); }
.button.secondary { color: var(--text); border-color: var(--line); }
.button.secondary:hover { border-color: var(--text); }

.device-figure { margin: 0; display: grid; justify-items: center; gap: 14px; }
.device {
  position: relative; width: min(100%, 440px); padding: 18px 18px 22px; border-radius: 22px;
  background: linear-gradient(160deg, #2b2f33, #15181a 60%);
  box-shadow: inset 0 1px 0 rgb(255 255 255 / .08), inset 0 -2px 0 rgb(0 0 0 / .5),
    0 1px 2px rgb(0 0 0 / .3), 0 24px 60px -20px rgb(0 0 0 / .55);
}
.device::before, .device::after { content: ""; position: absolute; width: 5px; height: 5px; border-radius: 50%; top: 8px;
  background: radial-gradient(circle at 35% 35%, #6b7177, #2a2e31); }
.device::before { left: 8px; } .device::after { right: 8px; }
.port { position: absolute; left: -5px; top: 50%; width: 5px; height: 26px; transform: translateY(-50%); border-radius: 3px 0 0 3px; background: #3a3f44; }
.screen { display: grid; grid-template-rows: 1fr auto; gap: 4px; aspect-ratio: 320 / 240; background: #101418;
  padding: 6px; border-radius: 6px; box-shadow: 0 0 0 1px rgb(0 0 0 / .6), 0 0 40px -8px rgb(255 255 255 / .08); }
.keys { display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(3, 1fr); gap: 5px; min-height: 0; }
.keys div { min-height: 0; overflow: hidden; border-radius: 6px; background: var(--key); color: var(--key-text);
  display: flex; align-items: center; justify-content: center; text-align: center; padding: 4px;
  font: 500 clamp(11px, 1.4vw, 14px)/1.2 var(--sans); animation: key-in .45s var(--ease) both; }
.keys div.blank { background: #181e25; }
.keys div.risky { box-shadow: inset 0 0 0 2px var(--signal); }
.keys .notes { grid-column: 1 / -1; grid-row: 1 / 3; justify-content: flex-start; align-items: flex-start; text-align: left;
  padding: 10px 12px; font: 13px/1.45 var(--sans); background: #1b2228; }
@keyframes key-in { from { opacity: 0; transform: scale(.94); } }
.bar { font: 11px/1.4 var(--mono); color: #c0c8d0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; padding: 2px 4px; }
figcaption { font: 500 11px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); display: flex; gap: 10px; align-items: center; }
.fig { color: var(--text); }
.live { color: var(--signal); display: inline-flex; align-items: center; gap: 6px; }
.live::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; animation: pulse 2.4s var(--ease) infinite; }
@keyframes pulse { 50% { transform: scale(.55); opacity: .5; } }

/* ---- sections ---- */
.cols4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 28px; }
.cols2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 28px; }
.grid3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 0 28px; }
.feat { padding: 18px 0; border-top: 1px solid var(--line); }
.tag { display: inline-block; font: 500 10px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
  padding: 5px 8px; border-radius: 999px; color: var(--signal); background: var(--signal-soft); margin: 0 0 10px; }

.flow { list-style: none; padding: 0; margin: 0 0 24px; display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 22px 28px; }
.flow li { display: flex; gap: 14px; }
.step-n { flex: none; width: 28px; height: 28px; border-radius: 50%; border: 1px solid var(--line); display: grid; place-items: center;
  font: 500 12px var(--mono); color: var(--signal); }
.code { margin: 0; overflow-x: auto; font: 13px/1.6 var(--mono); background: var(--raise); border: 1px solid var(--line);
  border-radius: 12px; padding: 18px 20px; max-width: 100%; }
.code .c { color: var(--faint); }

.rules { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px 28px; }
.rules li { padding-left: 18px; position: relative; }
.rules li::before { content: ""; position: absolute; left: 0; top: .6em; width: 7px; height: 7px; border-radius: 50%; background: var(--signal); }

.table-wrap { overflow-x: auto; margin-top: 8px; }
table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 560px; }
th { text-align: left; font: 500 11px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); padding: 10px 12px 10px 0; border-bottom: 1px solid var(--line); }
td { padding: 12px 12px 12px 0; border-bottom: 1px solid color-mix(in srgb, var(--line) 60%, transparent); }
.st { font: 500 10px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); padding: 4px 8px; border: 1px solid var(--line); border-radius: 999px; white-space: nowrap; }
.st.ok { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 40%, transparent); }

.steps { margin: 0; padding: 0; list-style: none; counter-reset: step; display: grid; gap: 14px; max-width: 760px; }
.steps li { counter-increment: step; position: relative; padding-left: 36px; overflow-wrap: anywhere; }
.steps li::before { content: counter(step, decimal-leading-zero); position: absolute; left: 0; font: 500 12px/2.1 var(--mono); color: var(--signal); }

.kb { gap: 12px 28px; margin-top: 8px; }
.kb-item { display: flex; flex-direction: column; gap: 2px; padding: 16px 0; border-top: 1px solid var(--line); text-decoration: none; transition: padding .2s var(--ease); }
.kb-item .tag { align-self: flex-start; }
.kb-item strong { font-weight: 600; }
.kb-item:hover strong { text-decoration: underline; text-decoration-color: var(--signal); text-underline-offset: 3px; }
.kb-item .muted { font-size: 14px; }
.faq-title { margin-top: 28px; }
.faq details { border-top: 1px solid var(--line); padding: 12px 0; max-width: 820px; }
.faq summary { cursor: pointer; font-weight: 500; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font: 500 16px var(--mono); color: var(--signal); }
.faq details[open] summary::after { content: "−"; }
.faq details p { color: var(--muted); margin: 10px 0 0; }

/* ---- video gallery ---- */
.gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.gallery .video:first-child { grid-column: 1 / -1; }
.photo { margin: 0; display: grid; gap: 12px; }
.photo img { display: block; width: 100%; max-height: 80vh; object-fit: cover; object-position: center 62%; border-radius: 14px; border: 1px solid var(--line); }
@media (max-width: 760px) { .gallery { grid-template-columns: 1fr; } .gallery .video:first-child { grid-row: auto; } }
.video { margin: 0; display: grid; gap: 10px; }
.frame { position: relative; aspect-ratio: 16 / 9; border-radius: 14px; overflow: hidden; border: 1px solid var(--line);
  background: repeating-linear-gradient(135deg, var(--raise) 0 12px, color-mix(in srgb, var(--line) 45%, var(--raise)) 12px 13px); }
.frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.frame img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.play { position: absolute; inset: 0; display: grid; place-items: center; align-content: center; gap: 12px; width: 100%;
  border: 0; background: transparent; color: var(--text); cursor: pointer; font: 500 11px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.play:disabled { cursor: default; color: var(--muted); }
.play .disc { width: 64px; height: 64px; border-radius: 50%; background: var(--ink); display: grid; place-items: center; transition: transform .2s var(--ease); }
.play .disc::after { content: ""; margin-left: 5px; border-left: 18px solid var(--ink-text); border-top: 11px solid transparent; border-bottom: 11px solid transparent; }
.play:not(:disabled):hover .disc { transform: scale(1.06); background: var(--signal); }
.play:not(:disabled) .label { color: #fff; text-shadow: 0 1px 3px rgb(0 0 0 / .6); }
.video figcaption { text-transform: none; letter-spacing: 0; font: 14px/1.4 var(--sans); color: var(--text); display: block; }
.video figcaption .fig { font: 500 11px var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--signal); margin-right: 8px; }

.foot { max-width: 1120px; margin: 0 auto; padding: 24px clamp(16px, 4vw, 40px) 48px; border-top: 1px solid var(--line);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; font-size: 14px; }

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

/* ---- the name: நோண்டு ---- */
[lang="ta"] { font-family: "Noto Sans Tamil", var(--sans); }
.name-grid { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: clamp(20px, 5vw, 56px); align-items: center; max-width: 900px; }
@media (max-width: 640px) { .name-grid { grid-template-columns: 1fr; } }
.tamil { margin: 0; font-size: clamp(52px, 9vw, 96px); font-weight: 600; line-height: 1.1; color: var(--signal); letter-spacing: -.01em; }
.pron { font: 500 12px/1.5 var(--mono); letter-spacing: .04em; color: var(--muted); }