/* ============================================================
   墨流 SUMINAGASHI — realtime marbling study.
   The canvas IS the page; UI floats like tools at a workbench.
   ============================================================ */

:root {
  --kami: #F3EEE3;            /* paper */
  --sumi: #221D16;            /* ink text */
  --usuzumi: rgba(34, 29, 22, .55);
  --shu: #B33A2B;             /* vermilion — active tool */
  --waku: rgba(34, 29, 22, .22);
  --serif: "Shippori Mincho B1", serif;
  --sans: "Zen Kaku Gothic New", sans-serif;
  --mono: "IBM Plex Mono", monospace;
}

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

html, body { height: 100%; }
body {
  font-family: var(--sans);
  color: var(--sumi);
  background: var(--kami);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
.mono { font-family: var(--mono); letter-spacing: .14em; }
.pc-only { display: inline; }

button:focus-visible {
  outline: 2px solid var(--shu);
  outline-offset: 2px;
}

/* ---------- canvas & paper grain ---------- */
#marble {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  cursor: crosshair;
  touch-action: none;
}
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .5;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0.55 0 0 0 0 0.52 0 0 0 0 0.46 0 0 0 0.05 0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- top bar ---------- */
.bar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 18px clamp(18px, 3.5vw, 40px);
  pointer-events: none;
}
.bar > * { pointer-events: auto; }
.bar__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: .1em;
}
.bar__brand .mono { font-size: 9.5px; color: var(--usuzumi); letter-spacing: .3em; padding-top: 4px; }
.bar__mark {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sumi);
  box-shadow: 3px 2px 0 -1px var(--shu);
}
.bar__count {
  margin-left: auto;
  font-size: 11px;
  color: var(--usuzumi);
  background: rgba(243, 238, 227, .72);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border-radius: 999px;
  padding: 5px 12px;
}
.bar__save {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .12em;
  border: 1px solid var(--waku);
  background: rgba(243, 238, 227, .72);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: 2px;
  padding: 9px 18px;
  transition: border-color .3s ease, color .3s ease;
}
.bar__save:hover { border-color: var(--shu); color: var(--shu); }

/* ---------- headline ---------- */
.lead {
  position: fixed;
  left: clamp(18px, 4vw, 56px);
  top: 50%;
  transform: translateY(-54%);
  z-index: 5;
  pointer-events: none;
  max-width: 400px;
}
.lead__label {
  display: inline-block;
  font-size: 10.5px;
  color: var(--usuzumi);
  background: rgba(243, 238, 227, .72);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border-radius: 999px;
  padding: 4px 12px;
  margin-bottom: 18px;
}
.lead__title {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(2.6rem, 6vw, 4.6rem);
  line-height: 1.32;
  letter-spacing: .06em;
  text-shadow: 0 0 18px rgba(243, 238, 227, .8), 0 0 42px rgba(243, 238, 227, .6);
  margin-bottom: 22px;
}
.lead__hints { display: flex; flex-wrap: wrap; gap: 7px; pointer-events: none; }
.lead__hints span {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--sumi);
  border: 1px solid var(--waku);
  background: rgba(243, 238, 227, .66);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border-radius: 999px;
  padding: 5px 13px;
}

/* ---------- honest caption ---------- */
.honest {
  position: fixed;
  left: 50%;
  bottom: 106px;
  transform: translateX(-50%);
  z-index: 5;
  font-size: 11.5px;
  letter-spacing: .12em;
  color: rgba(34, 29, 22, .74);
  background: rgba(243, 238, 227, .74);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: 999px;
  padding: 7px 18px;
  pointer-events: none;
  white-space: nowrap;
}

/* ---------- control tray ---------- */
.tray {
  position: fixed;
  left: 50%;
  bottom: 40px;
  transform: translateX(-50%);
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 16px;
  background: rgba(243, 238, 227, .78);
  border: 1px solid var(--waku);
  border-radius: 4px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 11px 18px;
  max-width: calc(100vw - 24px);
  overflow-x: auto;
}
.tray__group { display: flex; align-items: center; gap: 7px; }
.tray__label {
  font-size: 10px;
  letter-spacing: .2em;
  color: var(--usuzumi);
  margin-right: 3px;
  writing-mode: vertical-rl;
  line-height: 1;
}
.tray__sep { width: 1px; height: 26px; background: var(--waku); flex: none; }
.ink {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--c);
  border: 2px solid rgba(243, 238, 227, .9);
  box-shadow: 0 0 0 1px var(--waku);
  transition: transform .2s ease, box-shadow .2s ease;
  flex: none;
}
.ink:hover { transform: scale(1.12); }
.ink.is-on { box-shadow: 0 0 0 2px var(--shu); transform: scale(1.12); }
.tray__opt {
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--usuzumi);
  border: 1px solid transparent;
  border-radius: 2px;
  padding: 6px 12px;
  white-space: nowrap;
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}
.tray__opt:hover { color: var(--sumi); }
.tray__opt.is-on { color: var(--shu); border-color: rgba(179, 58, 43, .45); }
.tray__opt--reset:hover { color: var(--shu); }

/* ---------- credit ---------- */
.credit {
  position: fixed;
  right: clamp(14px, 2.5vw, 28px);
  bottom: 12px;
  z-index: 5;
  display: grid;
  gap: 2px;
  text-align: right;
  font-size: 8.5px;
  letter-spacing: .18em;
  color: rgba(34, 29, 22, .38);
  pointer-events: none;
}

/* ---------- responsive ---------- */
@media (max-width: 768px) {
  .pc-only { display: none; }
  .bar { gap: 12px; padding: 14px 14px; }
  .bar__brand { font-size: 14px; }
  .bar__brand .mono { display: none; }
  .bar__save { font-size: 11px; padding: 8px 12px; }
  .lead {
    left: 18px;
    right: 18px;
    top: auto;
    bottom: 172px;
    transform: none;
    max-width: none;
  }
  .lead__title { font-size: 2.3rem; }
  .lead__title br { display: none; }
  .honest {
    bottom: 80px;
    font-size: 10px;
    white-space: normal;
    text-align: center;
    width: calc(100vw - 40px);
  }
  .tray { bottom: 12px; gap: 10px; padding: 9px 12px; }
  .tray__label { display: none; }
  .credit { display: none; }
}

/* ---------- accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: .01ms !important; }
}