/* Keru OS website — Ryoku-style.
   Pure-black paper, warm bone ink, one vermillion accent.
   Radius 0. No shadow. Flat hairline surfaces. Monospace tech labels.
   Animations are loud enough to feel alive, flat enough to stay cool. */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  --paper: #000000;        /* pure black paper */
  --paper-2: #0d0d0d;      /* raised surface */
  --paper-3: #131313;      /* cards */
  --hair: #262626;         /* hairline borders */
  --ink: #cdc4ba;          /* warm bone ink — body */
  --ink-dim: #8b8275;      /* subdued ink */
  --ink-faint: #5b5348;    /* farthest faded */
  --bone: #f2ede4;         /* bright ink, emphasis */
  --accent: #ff3b1f;       /* vermillion — the single accent */
  --ok: #58e1c2;
  --warn: #f0a35e;
  --danger: #ff3b1f;
  --mono: 'JetBrains Mono', ui-monospace, monospace;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
  --radius: 0;             /* sharp. always. */
  --nav-h: 60px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
::selection { background: var(--accent); color: #000; }
html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* faint scanline texture — a taste of grain, no image */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    repeating-linear-gradient(180deg, transparent 0 3px, rgba(255,255,255,.008) 3px 4px);
  pointer-events: none;
}

a { color: var(--ink); text-decoration: none; }
a:hover { color: var(--bone); }

/* ---------- top nav ---------- */
nav.top {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(0,0,0,.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--hair);
  display: flex;
  align-items: center;
  padding: 0 26px;
  gap: 4px;
}
.brand {
  font-family: var(--mono);
  font-weight: 700;
  color: var(--bone);
  font-size: 1rem;
  letter-spacing: .02em;
  margin-right: auto;
  display: flex;
  align-items: center;
  gap: 9px;
}
.brand .kanji {
  color: var(--accent);
  font-size: 1.15rem;
  text-shadow: 0 0 14px rgba(255,59,31,.55);
}
.brand:hover { text-decoration: none; }

nav.top a.navlink {
  color: var(--ink-dim);
  font-family: var(--mono);
  text-transform: uppercase;
  font-size: .72rem;
  letter-spacing: .12em;
  padding: 6px 10px;
  border: 1px solid transparent;
  transition: color .15s, border-color .15s, background .15s;
}
nav.top a.navlink:hover {
  color: var(--bone);
  border-color: var(--hair);
  background: var(--paper-2);
  text-decoration: none;
}
.menu-toggle { display: none; }

/* ---------- hero ---------- */
.hero { padding: 84px 26px 54px; text-align: center; }

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  color: var(--ink-dim);
  text-transform: uppercase;
  font-size: .72rem;
  letter-spacing: .22em;
  border: 1px solid var(--hair);
  background: var(--paper-2);
  padding: 5px 14px;
}
.kicker .dot {
  width: 7px; height: 7px; background: var(--accent);
  animation: pulse 1.6s infinite;
}
.kicker .dot.dim { background: var(--ink-faint); }

.hero .seal {
  font-size: 5rem;
  line-height: 1;
  color: var(--bone);
  user-select: none;
  display: block;
  margin: 18px auto 6px;
  animation: fadeUp .7s ease both;
}
.hero h1 {
  font-family: var(--mono);
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--bone);
  letter-spacing: .02em;
  margin: 14px auto 16px;
  text-transform: uppercase;
}
.hero h1 .grad { color: var(--accent); }
.hero p.sub { color: var(--ink-dim); max-width: 620px; margin: 0 auto 30px; font-size: 1rem; }

.cta-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: .1em;
  font-size: .78rem;
  font-weight: 700;
  padding: 12px 22px;
  border: 1px solid var(--ink-dim);
  color: var(--bone);
  transition: color .15s, background .15s, border-color .15s, transform .1s;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #000; }
.btn-primary:hover { background: #000; color: var(--accent); }
.btn-ghost { background: transparent; color: var(--ink-dim); }
.btn-ghost:hover { background: var(--paper-2); color: var(--bone); border-color: var(--accent); }

/* ---------- marquee ticker ---------- */
.ticker {
  overflow: hidden;
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
  padding: 13px 0;
  background: var(--paper-2);
  white-space: nowrap;
}
.ticker-inner {
  display: inline-block;
  animation: ticker 32s linear infinite;
  font-family: var(--mono);
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--ink-faint);
}
.ticker-inner span { margin: 0 26px; }
.ticker-inner b { color: var(--bone); font-weight: 500; }
.ticker-inner .a { color: var(--accent); }

/* ---------- sections ---------- */
section { padding: 54px 26px; }
.wrap { max-width: 1080px; margin: 0 auto; }

.section-title {
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: .2em;
  font-size: .7rem;
  color: var(--accent);
  margin-bottom: 10px;
}
.section-title::before { content: "// "; opacity: .6; }
h2.head {
  font-family: var(--mono);
  font-size: clamp(1.25rem, 3vw, 1.9rem);
  color: var(--bone);
  font-weight: 700;
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: .02em;
}
.lead { color: var(--ink-dim); font-size: 1rem; max-width: 720px; margin-bottom: 28px; }

.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }

.card {
  background: var(--paper-2);
  border: 1px solid var(--hair);
  padding: 20px;
  position: relative;
  transition: border-color .15s, transform .1s, background .15s;
}
.card::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 2px;
  background: var(--accent);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .25s cubic-bezier(.2,.8,.2,1);
}
.card:hover { border-color: var(--accent); background: var(--paper-3); transform: translateY(-2px); }
.card:hover::before { transform: scaleY(1); }
.card.h {
  font-family: var(--mono);
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--bone);
  margin-bottom: 8px;
}
.card p { color: var(--ink-dim); font-size: .92rem; }
.card .num {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--hair);
  padding: 2px 8px;
  display: inline-block;
  margin-bottom: 10px;
}
a.card { color: inherit; }
a.card:hover { text-decoration: none; }

/* ---------- terminal / code ---------- */
.terminal {
  background: #050505;
  border: 1px solid var(--hair);
  overflow: hidden;
  text-align: left;
  margin: 0 auto;
  max-width: 660px;
}
.terminal .tbar {
  background: var(--paper-2);
  padding: 9px 12px;
  display: flex;
  gap: 6px;
  align-items: center;
  border-bottom: 1px solid var(--hair);
}
.terminal .tbar span.dot { width: 9px; height: 9px; display: inline-block; }
.terminal .tbar .r { background: var(--danger); }
.terminal .tbar .y { background: var(--warn); }
.terminal .tbar .g { background: var(--ok); }
.terminal .tbar .t {
  margin-left: 10px;
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--ink-faint);
  text-transform: uppercase;
  letter-spacing: .1em;
}
.terminal pre { padding: 18px; overflow-x: auto; font-family: var(--mono); font-size: .84rem; line-height: 1.75; color: var(--ink); }
.terminal .c { color: var(--accent); }
.terminal .k { color: var(--bone); }
.terminal .p { color: var(--ink-faint); }

pre, code, kbd { font-family: var(--mono); }
.code-block {
  background: #050505;
  border: 1px solid var(--hair);
  border-left: 3px solid var(--accent);
  padding: 18px;
  overflow-x: auto;
  margin: 18px 0;
  font-size: .84rem;
  line-height: 1.7;
  color: var(--ink);
}
code:not(.code-block) {
  background: var(--paper-2);
  border: 1px solid var(--hair);
  padding: 2px 6px;
  font-size: .85em;
  color: var(--accent);
}
kbd {
  background: var(--paper-2);
  border: 1px solid var(--hair);
  border-bottom-width: 2px;
  padding: 1px 6px;
  font-size: .8em;
}

/* ---------- prose ---------- */
.prose { max-width: 760px; margin: 0 auto; }
.prose h3 {
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--bone);
  font-size: 1.1rem;
  margin: 32px 0 10px;
  font-weight: 700;
}
.prose h3::before { content: "# "; color: var(--accent); }
.prose h4 { color: var(--accent); margin: 22px 0 8px; font-size: .95rem; font-family: var(--mono); }
.prose p { margin: 12px 0; color: var(--ink); }
.prose ul, .prose ol { margin: 12px 0 12px 22px; }
.prose li { margin: 6px 0; color: var(--ink); }
.prose li::marker { color: var(--accent); }
.prose blockquote {
  border-left: 3px solid var(--accent);
  background: var(--paper-2);
  padding: 14px 18px;
  margin: 18px 0;
  color: var(--ink-dim);
}
.prose blockquote strong { color: var(--bone); }
.prose hr { border: none; border-top: 1px solid var(--hair); margin: 30px 0; }

table { border-collapse: collapse; width: 100%; margin: 18px 0; font-size: .92rem; }
th, td { border: 1px solid var(--hair); padding: 9px 12px; text-align: left; }
th { background: var(--paper-2); color: var(--bone); font-family: var(--mono); font-size: .78rem; text-transform: uppercase; letter-spacing: .05em; }
tr:nth-child(even) td { background: rgba(255,255,255,.02); }

/* tags / callouts */
.tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: .66rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  padding: 2px 9px;
  border: 1px solid var(--hair);
  color: var(--ink-dim);
  margin: 2px 4px 2px 0;
}
.tag.warn { color: var(--warn); border-color: var(--warn); }
.tag.danger { color: var(--danger); border-color: var(--danger); }
.tag.ok { color: var(--ok); border-color: var(--ok); }
.tag.accent { color: var(--accent); border-color: var(--accent); }

.callout {
  border: 1px solid var(--hair);
  border-left: 3px solid var(--accent);
  background: var(--paper-2);
  padding: 14px 18px;
  margin: 18px 0;
}
.callout.warn { border-left-color: var(--warn); }
.callout.danger { border-left-color: var(--danger); }
.callout.ok { border-left-color: var(--ok); }

.features { list-style: none; margin: 0; }
.features li { padding: 9px 0; border-bottom: 1px solid var(--hair); display: flex; gap: 12px; color: var(--ink); }
.features li::before { content: "▸"; color: var(--accent); }

/* ---------- news ---------- */
.post-list { max-width: 820px; margin: 0 auto; }
.post-item {
  display: block;
  background: var(--paper-2);
  border: 1px solid var(--hair);
  padding: 20px 22px;
  margin-bottom: 14px;
  transition: border-color .15s, transform .1s;
}
.post-item:hover { transform: translateX(4px); border-color: var(--accent); text-decoration: none; }
.post-item h3 { color: var(--bone); font-family: var(--mono); font-size: 1.05rem; text-transform: uppercase; letter-spacing: .03em; margin-bottom: 6px; }
.post-item .meta { font-family: var(--mono); font-size: .72rem; color: var(--ink-faint); text-transform: uppercase; letter-spacing: .1em; margin-bottom: 6px; }
.post-item p { color: var(--ink-dim); font-size: .92rem; }

/* ---------- footer ---------- */
footer { border-top: 1px solid var(--hair); background: var(--paper-2); padding: 38px 26px 30px; margin-top: 40px; }
footer .wrap { display: flex; gap: 34px; flex-wrap: wrap; justify-content: space-between; }
footer h4 { color: var(--bone); font-family: var(--mono); font-size: .72rem; text-transform: uppercase; letter-spacing: .16em; margin-bottom: 12px; }
footer h4::before { content: "// "; color: var(--accent); }
footer ul { list-style: none; }
footer li { margin: 6px 0; }
footer a { color: var(--ink-dim); }
footer a:hover { color: var(--bone); text-decoration: none; }
footer .foot {
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid var(--hair);
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--ink-faint);
  text-align: center;
  text-transform: uppercase;
  letter-spacing: .12em;
}
footer .marks { color: var(--accent); }

/* ---------- stats ---------- */
.stats { display: flex; gap: 30px; flex-wrap: wrap; justify-content: center; margin: 22px 0; }
.stat { text-align: center; border: 1px solid var(--hair); padding: 18px 26px; background: var(--paper-2); min-width: 150px; }
.stat .big { font-family: var(--mono); font-size: 2.2rem; font-weight: 700; color: var(--bone); }
.stat .lbl { color: var(--ink-faint); font-size: .72rem; text-transform: uppercase; letter-spacing: .12em; font-family: var(--mono); }

/* dossier block (Ryoku-style system sheet) */
.dossier {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
  margin: 26px auto;
  max-width: 680px;
  text-align: left;
}
.dossier .row {
  background: var(--paper-2);
  padding: 12px 18px;
  font-family: var(--mono);
  font-size: .78rem;
  display: flex;
  justify-content: space-between;
  gap: 16px;
}
.dossier .row .lbl { color: var(--ink-faint); text-transform: uppercase; letter-spacing: .1em; }
.dossier .row .val { color: var(--bone); text-align: right; }
.dossier .row .val.a { color: var(--accent); }

/* ---------- animations ---------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeLeft {
  from { opacity: 0; transform: translateX(-14px); }
  to { opacity: 1; transform: translateX(0); }
}
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .25; } }
@keyframes blink { 0%,49% { opacity: 1; } 50%,100% { opacity: 0; } }
@keyframes ticker { from { transform: translateX(0); } to { transform: translateX(-50%); } }
@keyframes sweep {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.reveal { animation: fadeUp .6s ease both; }
.d1 { animation-delay: .08s; }
.d2 { animation-delay: .16s; }
.d3 { animation-delay: .24s; }
.d4 { animation-delay: .32s; }
.d5 { animation-delay: .40s; }

/* blinking caret after brand */
.caret { display: inline-block; width: 8px; height: 1em; background: var(--accent); margin-left: 2px; vertical-align: -0.15em; animation: blink 1.1s infinite; }

/* accent headline underline sweep on hover */
.head { background: linear-gradient(90deg, var(--accent), var(--accent), var(--accent)) no-repeat;
  background-size: 0% 2px; background-position: 0 100%; transition: background-size .3s ease; }
.head:hover { background-size: 100% 2px; }

/* text flicker on the kanji seal */
.seal { animation: flicker 4s infinite; }
@keyframes flicker {
  0%,100% { opacity: 1; }
  92% { opacity: 1; } 93% { opacity: .4; } 94% { opacity: 1; }
}

/* ---------- pagehead ---------- */
.pagehead { padding: 64px 26px 30px; text-align: center; }
.pagehead h1 { font-family: var(--mono); text-transform: uppercase; letter-spacing: .02em; color: var(--bone); font-size: clamp(1.6rem, 4vw, 2.4rem); font-weight: 700; }
.pagehead p { color: var(--ink-dim); max-width: 620px; margin: 12px auto 0; }
.crumbs { font-family: var(--mono); font-size: .72rem; color: var(--ink-faint); text-transform: uppercase; letter-spacing: .12em; max-width: 760px; margin: 18px auto 0; }
.crumbs a { color: var(--ink-dim); }
.crumbs a:hover { color: var(--accent); }
.crumbs span { color: var(--accent); }

/* responsive */
@media (max-width: 720px) {
  nav.top { padding: 0 14px; }
  nav.top a.navlink { display: none; }
  .menu-toggle { display: inline-flex; }
  .hero { padding: 56px 18px 34px; }
  section { padding: 38px 18px; }
  footer .wrap { gap: 20px; }
  .dossier { grid-template-columns: 1fr; }
}