/* ============================================================
   HASHBIT Inc. — Design System
   Monochrome / warm-neutral / HASHBIT green accent
   ============================================================ */

:root {
  /* warm neutral mono ramp */
  --bg:        #f4f3f0;
  --bg-2:      #eceae5;
  --paper:     #fbfbf9;
  --ink:       #0c0c0b;
  --ink-2:     #54524d;
  --ink-3:     #8d8a83;
  --line:      #dedcd6;
  --line-2:    #cbc8c1;
  --on-dark:   #f4f3f0;
  --ink-dark:  #0c0c0b;

  /* brand accent */
  --accent:    #7ae800;   /* HASHBIT green */
  --accent-soft: rgba(122, 232, 0, .12);

  --maxw: 1320px;
  --gut: clamp(20px, 5vw, 64px);

  --mono: "Roboto Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --sans: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "YuGothic",
          "Yu Gothic", "Noto Sans JP", system-ui, sans-serif;

  --ease: cubic-bezier(.22, 1, .36, 1);
  --ease-2: cubic-bezier(.65, 0, .35, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--ink);
  font-weight: 500;
  line-height: 1.7;
  letter-spacing: .01em;
  overflow-x: hidden;
}

::selection { background: var(--accent); color: var(--ink); }

.mono {
  font-family: var(--mono);
  font-weight: 500;
  letter-spacing: .04em;
  font-feature-settings: "tnum" 1;
}

/* ---------- layout ---------- */
.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gut); }
.section { position: relative; }

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
img { display: block; max-width: 100%; }

/* hairline label */
.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--ink-3);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 28px; height: 1px;
  background: var(--line-2);
}
.eyebrow .idx { color: var(--accent); }

/* section index marker top-right */
.sec-head {
  display: flex; justify-content: space-between; align-items: baseline;
  border-top: 1px solid var(--line);
  padding-top: 22px;
  gap: 24px;
  flex-wrap: wrap;
}

h1,h2,h3 { font-weight: 700; line-height: 1.18; letter-spacing: .005em; }

.display {
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  font-size: clamp(34px, 6.4vw, 92px);
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 15px; font-weight: 700;
  white-space: nowrap;
  padding: 15px 26px;
  border: 1px solid var(--ink);
  background: var(--ink); color: var(--on-dark);
  transition: transform .4s var(--ease), background .3s, color .3s, gap .3s;
  position: relative; overflow: hidden;
}
.btn .arr { transition: transform .4s var(--ease); }
.btn:hover { gap: 18px; }
.btn:hover .arr { transform: translateX(4px); }
.btn:active { transform: scale(.98); }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { background: var(--ink); color: var(--on-dark); }
.btn.accent { background: var(--accent); border-color: var(--accent); color: var(--ink); }

.btn-sq { width: 12px; height: 12px; }

/* ---------- reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: .08s; }
.reveal.d2 { transition-delay: .16s; }
.reveal.d3 { transition-delay: .24s; }
.reveal.d4 { transition-delay: .32s; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1 !important; transform: none !important; }
}

/* line-by-line clip reveal for headings */
.lines span { display: block; overflow: hidden; }
.lines span > i {
  display: block; font-style: normal;
  transform: translateY(110%);
  transition: transform 1s var(--ease);
}
.lines.in span > i { transform: none; }
.lines.in span:nth-child(2) > i { transition-delay: .09s; }
.lines.in span:nth-child(3) > i { transition-delay: .18s; }
@media (prefers-reduced-motion: reduce){ .lines span>i{transform:none;} }

/* ---------- nav ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  height: 68px;
  display: flex; align-items: center;
  border-bottom: 1px solid transparent;
  transition: background .4s var(--ease), border-color .4s, backdrop-filter .4s;
}
.nav.solid {
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(1.2);
  border-color: var(--line);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.brand { display: flex; align-items: center; }
.brand-logo { height: 26px; width: auto; display: block; }
.navlinks { display: flex; gap: 4px; align-items: center; }
.navlinks a {
  font-size: 13.5px; font-weight: 600; padding: 9px 14px; color: var(--ink-2);
  position: relative; transition: color .3s;
}
.navlinks a .en { font-family: var(--mono); font-size: 10px; letter-spacing: .12em; color: var(--ink-3); display:block; margin-top:-3px; }
.navlinks a:hover { color: var(--ink); }
.navlinks a.active { color: var(--ink); }
.navlinks a.active::after {
  content:""; position:absolute; left:14px; right:14px; bottom:3px; height:2px; background: var(--accent);
}
.nav-cta { display:flex; align-items:center; gap:14px; }
.menu-btn { display:none; }

.mobile-menu { display: none; }

@media (max-width: 920px) {
  .navlinks { display: none; }
  .menu-btn { display: flex; flex-direction: column; gap: 5px; padding: 8px; }
  .menu-btn i { width: 22px; height: 2px; background: var(--ink); transition: transform .4s var(--ease), opacity .3s; }
  .menu-btn.open i:nth-child(1){ transform: translateY(7px) rotate(45deg);}
  .menu-btn.open i:nth-child(2){ opacity:0;}
  .menu-btn.open i:nth-child(3){ transform: translateY(-7px) rotate(-45deg);}
  .mobile-menu {
    position: fixed; inset: 68px 0 auto 0; z-index: 99;
    background: var(--bg); border-bottom: 1px solid var(--line);
    display: flex; flex-direction: column; padding: 8px var(--gut) 24px;
    transform: translateY(calc(-100% - 72px));
    visibility: hidden;
    pointer-events: none;
    transition: transform .5s var(--ease), visibility 0s linear .5s;
  }
}
.mobile-menu.open { transform: none; visibility: visible; pointer-events: auto; transition-delay: 0s; }
.mobile-menu a { padding: 16px 0; border-bottom: 1px solid var(--line); font-weight:700; font-size:20px; display:flex; justify-content:space-between; align-items:baseline;}
.mobile-menu a .en { font-family:var(--mono); font-size:12px; color: var(--ink-3);}

/* ---------- footer ---------- */
.footer { background: var(--ink-dark); color: var(--on-dark); padding: 80px 0 40px; margin-top: 0; }
.footer a { color: var(--ink-3); transition: color .3s; }
.footer a:hover { color: #fff; }

/* dotted grid bg helper */
.dotgrid {
  background-image: radial-gradient(var(--line-2) 1px, transparent 1px);
  background-size: 26px 26px;
}

/* utility */
.kicker-row { display:flex; gap:10px; align-items:center; flex-wrap:wrap; }
.tag {
  font-family: var(--mono); font-size: 11px; letter-spacing:.06em;
  padding: 5px 10px; border: 1px solid var(--line-2); color: var(--ink-2);
  white-space: nowrap;
}
.tag.solid { background: var(--ink); color: var(--on-dark); border-color: var(--ink); }
.tag.dot::before { content:""; display:inline-block; width:6px; height:6px; border-radius:50%; background: var(--accent); margin-right:6px; vertical-align: middle; }

.hr { height:1px; background: var(--line); border:0; }