/* ————————————————————————————————————————————————
   Infinite Sudoku · The Long Trail
   A Pacific Northwest thru-hike in 192 sudoku camps.
   ———————————————————————————————————————————————— */

:root {
  --font-display: "Fraunces", "Iowan Old Style", Georgia, serif;
  --font-ui: "Karla", "Avenir Next", system-ui, sans-serif;

  /* daylight — cream paper, fir ink, moss, clay, river */
  --paper: #f3efe4;
  --paper-deep: #eae5d4;
  --card: #faf7ee;
  --ink: #2b3a2e;
  --ink-soft: #5c6a55;
  --ink-faint: #8b957f;
  --moss: #5a7058;
  --moss-wash: rgba(90, 112, 88, 0.13);
  --moss-wash-strong: rgba(90, 112, 88, 0.26);
  --peer-wash: rgba(90, 112, 88, 0.055);
  --clay: #b4643f;
  --clay-wash: rgba(180, 100, 63, 0.16);
  --river: #53707f;
  --line-soft: rgba(43, 58, 46, 0.14);
  --line-strong: rgba(43, 58, 46, 0.52);
  --shadow-ground: 0 1px 2px rgba(43, 58, 46, 0.05);
  --shadow-lift: 0 1px 2px rgba(43, 58, 46, 0.05), 0 12px 32px rgba(43, 58, 46, 0.10);
  --shadow-float: 0 2px 6px rgba(28, 38, 30, 0.08), 0 24px 64px rgba(28, 38, 30, 0.18);

  --ease-trail: cubic-bezier(0.32, 0.72, 0, 1);
  --dur-fast: 140ms;
  --dur-base: 280ms;
  --dur-slow: 480ms;

  color-scheme: light dark;
}

/* night hike */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #141a14;
    --paper-deep: #10150f;
    --card: #1b231a;
    --ink: #e9e6d6;
    --ink-soft: #a9b29a;
    --ink-faint: #79836c;
    --moss: #8ca380;
    --moss-wash: rgba(140, 163, 128, 0.16);
    --moss-wash-strong: rgba(140, 163, 128, 0.30);
    --peer-wash: rgba(140, 163, 128, 0.07);
    --clay: #d08a63;
    --clay-wash: rgba(208, 138, 99, 0.19);
    --river: #8fb0c1;
    --line-soft: rgba(233, 230, 214, 0.13);
    --line-strong: rgba(233, 230, 214, 0.46);
    --shadow-ground: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-lift: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 32px rgba(0, 0, 0, 0.35);
    --shadow-float: 0 2px 6px rgba(0, 0, 0, 0.4), 0 24px 64px rgba(0, 0, 0, 0.5);
  }
}
:root[data-theme="dark"] {
  --paper: #141a14;
  --paper-deep: #10150f;
  --card: #1b231a;
  --ink: #e9e6d6;
  --ink-soft: #a9b29a;
  --ink-faint: #79836c;
  --moss: #8ca380;
  --moss-wash: rgba(140, 163, 128, 0.16);
  --moss-wash-strong: rgba(140, 163, 128, 0.30);
  --peer-wash: rgba(140, 163, 128, 0.07);
  --clay: #d08a63;
  --clay-wash: rgba(208, 138, 99, 0.19);
  --river: #8fb0c1;
  --line-soft: rgba(233, 230, 214, 0.13);
  --line-strong: rgba(233, 230, 214, 0.46);
  --shadow-ground: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-lift: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 32px rgba(0, 0, 0, 0.35);
  --shadow-float: 0 2px 6px rgba(0, 0, 0, 0.4), 0 24px 64px rgba(0, 0, 0, 0.5);
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100dvh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 1rem;
  line-height: 1.5;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

/* paper grain */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 40;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='240' height='240' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
}

.app {
  max-width: 34.5rem;
  margin: 0 auto;
  padding: 0 1.25rem 4rem;
}

/* ————— top bar ————— */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 0 0;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.wordmark-tree { width: 1rem; height: 1rem; color: var(--moss); }

.topbar-right { display: inline-flex; align-items: center; gap: 0.5rem; }

.trail-time {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  border: none;
  border-radius: 0.75rem;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-trail);
}
.icon-btn:hover { background: var(--peer-wash); }
.icon-btn svg { width: 1.125rem; height: 1.125rem; }
.ic-sun { display: none; }
[data-theme="dark"] .ic-moon { display: none; }
[data-theme="dark"] .ic-sun { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .ic-moon { display: none; }
  :root:not([data-theme="light"]) .ic-sun { display: block; }
}

/* ————— trailhead / progress ————— */

.trailhead {
  text-align: center;
  padding: 2.25rem 0 0.5rem;
}

.camp-meta {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
}

.leg-name {
  margin: 0.375rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(2.375rem, 9vw, 3.25rem);
  font-weight: 470;
  font-style: italic;
  line-height: 1.05;
  letter-spacing: -0.015em;
  color: var(--ink);
  font-variation-settings: "SOFT" 100, "WONK" 1, "opsz" 90;
}

.ridge {
  position: relative;
  height: 4.5rem;
  margin-top: 1.375rem;
}
.ridge svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.ridge-dot {
  position: absolute;
  width: 0.5625rem;
  height: 0.5625rem;
  border-radius: 50%;
  background: var(--clay);
  transform: translate(-50%, -50%);
  transition: left var(--dur-slow) var(--ease-trail), top var(--dur-slow) var(--ease-trail);
}
.ridge-dot::after {
  content: "";
  position: absolute;
  inset: -0.4375rem;
  border-radius: 50%;
  border: 1.5px solid var(--clay);
  opacity: 0.35;
  animation: halo 3.2s var(--ease-trail) infinite;
}
@keyframes halo {
  0%, 100% { transform: scale(0.72); opacity: 0.4; }
  50% { transform: scale(1); opacity: 0.12; }
}

/* ————— board ————— */

.board-wrap { padding-top: 1.75rem; }

.board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  aspect-ratio: 1;
  width: 100%;
  background: var(--card);
  border: 1.5px solid var(--line-strong);
  border-radius: 1.25rem;
  overflow: hidden;
  box-shadow: var(--shadow-lift);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

.cell {
  position: relative;
  display: grid;
  place-items: center;
  padding: 0;
  border: none;
  border-right: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  background: transparent;
  font-family: var(--font-display);
  font-size: clamp(1.1875rem, 4.6vmin, 1.75rem);
  font-weight: 560;
  font-variant-numeric: lining-nums tabular-nums;
  color: var(--ink);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-trail);
}
.cell:nth-child(9n) { border-right: none; }
.cell:nth-child(n+73) { border-bottom: none; }
.cell:nth-child(3n):not(:nth-child(9n)) { border-right: 1.5px solid var(--line-strong); }
.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54) { border-bottom: 1.5px solid var(--line-strong); }

.cell.peer { background: var(--peer-wash); }
.cell.same { background: var(--moss-wash); }
.cell.sel { background: var(--moss-wash-strong); }
.cell.user { color: var(--river); }
.cell.conflict { background: var(--clay-wash); color: var(--clay); }
.cell.sel.conflict { background: var(--clay-wash); }

.cell:focus-visible {
  outline: 2px solid var(--moss);
  outline-offset: -2px;
  border-radius: 0.375rem;
}

.cell .notes {
  position: absolute;
  inset: 6%;
  display: grid;
  grid-template: repeat(3, 1fr) / repeat(3, 1fr);
  place-items: center;
  font-family: var(--font-ui);
  font-size: clamp(0.5rem, 1.7vmin, 0.6875rem);
  font-weight: 600;
  color: var(--ink-soft);
  pointer-events: none;
}

/* ————— controls ————— */

.controls { padding-top: 1.375rem; }

.tools {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  padding-bottom: 0.875rem;
}

.tool {
  display: inline-flex;
  align-items: center;
  gap: 0.4375rem;
  min-height: 2.75rem;
  padding: 0 1.125rem;
  border: 1px solid var(--line-soft);
  border-radius: 0.875rem;
  background: transparent;
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  font-weight: 650;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-trail), color var(--dur-fast) var(--ease-trail), border-color var(--dur-fast) var(--ease-trail);
}
.tool svg { width: 1rem; height: 1rem; }
.tool:hover { background: var(--peer-wash); }
.tool[aria-pressed="true"] {
  background: var(--clay-wash);
  border-color: transparent;
  color: var(--clay);
}

.pad {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 0.375rem;
}

.key {
  min-height: 3.25rem;
  border: none;
  border-radius: 0.75rem;
  background: var(--paper-deep);
  box-shadow: var(--shadow-ground);
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 560;
  font-variant-numeric: lining-nums;
  color: var(--ink);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-trail), transform var(--dur-fast) var(--ease-trail), opacity var(--dur-base) var(--ease-trail);
}
.key:hover { background: var(--moss-wash); }
.key:active { transform: translateY(1px) scale(0.97); }
.key.spent { opacity: 0.28; }

.tool:focus-visible, .key:focus-visible, .icon-btn:focus-visible, .linklike:focus-visible {
  outline: 2px solid var(--moss);
  outline-offset: 2px;
}

/* ————— footer ————— */

.foot {
  text-align: center;
  padding-top: 3.5rem;
  color: var(--ink-faint);
}
.foot-firs {
  width: 3.5rem;
  height: auto;
  color: var(--moss);
  opacity: 0.55;
}
.foot p {
  margin: 0.875rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.6;
}
.foot-fine { opacity: 0.85; }
.linklike {
  border: none;
  background: none;
  padding: 0;
  font: inherit;
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 2px;
  cursor: pointer;
}
.linklike:hover { color: var(--clay); }

/* ————— veil + panel ————— */

.veil {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 1.5rem;
  background: color-mix(in srgb, var(--paper) 55%, transparent);
  -webkit-backdrop-filter: saturate(140%) blur(18px);
  backdrop-filter: saturate(140%) blur(18px);
}
.veil[hidden] { display: none; }

.panel {
  width: min(25rem, 100%);
  padding: 2.5rem 2.25rem 2.25rem;
  background: var(--card);
  border-radius: 1.75rem;
  box-shadow: var(--shadow-float);
  text-align: center;
  animation: panel-in var(--dur-base) var(--ease-trail);
}
@keyframes panel-in {
  from { opacity: 0; transform: translateY(0.75rem) scale(0.97); }
  to { opacity: 1; transform: none; }
}

.panel-eyebrow {
  margin: 0;
  font-size: 0.6875rem;
  font-weight: 650;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--clay);
  font-variant-numeric: tabular-nums;
}

.panel-title {
  margin: 0.625rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 8vw, 2.875rem);
  font-weight: 470;
  font-style: italic;
  line-height: 1.02;
  letter-spacing: -0.015em;
  font-variation-settings: "SOFT" 100, "WONK" 1, "opsz" 80;
}

.panel-body {
  margin: 1.125rem auto 0;
  max-width: 21rem;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

.cta {
  display: inline-block;
  margin-top: 1.625rem;
  min-height: 3rem;
  padding: 0.75rem 1.75rem;
  border: none;
  border-radius: 62rem;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-ui);
  font-size: 0.9375rem;
  font-weight: 650;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: transform var(--dur-fast) var(--ease-trail), opacity var(--dur-fast) var(--ease-trail);
}
.cta:hover { opacity: 0.88; }
.cta:active { transform: translateY(1px) scale(0.98); }
.cta:focus-visible { outline: 2px solid var(--moss); outline-offset: 3px; }

.panel-fine {
  margin: 1.25rem 0 0;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}

/* ————— responsive + motion ————— */

@media (min-width: 40rem) {
  .topbar { padding-top: 2.25rem; }
  .trailhead { padding-top: 3rem; }
  .ridge { height: 5.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}