/* ==========================================================================
   Digigma SEO Sites Factory — V2/V3 shared socle
   DEV/PREVIEW ONLY — not deployed live

   One structure for every domain. Identity comes from tokens injected
   per site (:root in the generated page): palette, type, gradients,
   motif, grid logo, and wordmark. V3 examples add premium surfaces.
   ========================================================================== */

:root {
  --color-primary: #1c3d2e;
  --color-primary-light: #2f5d45;
  --color-secondary: #efe8da;
  --color-accent: #a6853f;
  --color-accent-light: #c4a35a;
  --color-surface: #fbf8f2;
  --color-surface-alt: #e7dfd0;
  --color-text: #1a241c;
  --color-text-muted: #5c6b60;
  --color-border: #ddd2bc;
  --color-success: #2f6b45;
  --color-error: #9d2c2c;
  --color-cta: var(--color-primary);
  --color-cta-fg: #ffffff;
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Source Sans 3", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  /* Puzzle digits: UI stack for even stroke weight (not display serifs). */
  --font-puzzle: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-weight-puzzle: 600;
  --font-weight-puzzle-given: 700;
  --font-size-base: 17px;
  --font-weight-display: 560;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-btn: 999px;
  --header-gradient: linear-gradient(90deg, #1c3d2e, #a6853f);
  --mark-gradient: var(--header-gradient);
  --page-bg: #efe8da;
  --header-bg: color-mix(in srgb, var(--color-surface) 86%, transparent);
  --header-fg: var(--color-text);
  --header-border: color-mix(in srgb, var(--color-border) 80%, transparent);
  --hero-glow: color-mix(in srgb, var(--color-primary) 22%, transparent);
  --hero-glow-2: color-mix(in srgb, var(--color-accent) 28%, transparent);
  --stage-bg: var(--color-surface);
  --footer-bg: #14281c;
  --footer-fg: #f6f3ec;
  --footer-muted: color-mix(in srgb, var(--footer-fg) 68%, transparent);
  --on-primary: #ffffff;
  --focus-ring: var(--color-accent);
  --shadow-card: 0 16px 40px -28px rgba(28, 61, 46, 0.45);
  --shadow-stage: 0 30px 70px -36px color-mix(in srgb, var(--color-primary) 55%, black);
  --wordmark-tracking: -0.03em;
  --wordmark-transform: none;
  --wordmark-style: normal;
  --mark-radius: var(--radius-md);
  --geo-stripe: transparent;
  --container-width: 1120px;
  --transition: 180ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background:
    radial-gradient(1200px 600px at 50% -20%, color-mix(in srgb, var(--color-primary) 6%, transparent), transparent 55%),
    var(--page-bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-feature-settings: "kern", "liga", "calt";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  display: block;
  max-width: 100%;
}

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
}

a {
  color: var(--color-primary);
  text-underline-offset: 3px;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-primary-light);
}

main {
  flex: 1;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: 0;
  transform: translateY(-120%);
  background: var(--color-surface);
  color: var(--color-text);
  padding: 0.6rem 0.9rem;
  border-radius: var(--radius-sm);
  z-index: 2000;
  text-decoration: none;
  font-weight: 650;
}

.skip-link:focus {
  transform: translateY(0.6rem);
}

/* --- Dev banner ----------------------------------------------------------- */
.sticky-stack {
  position: sticky;
  top: 0;
  z-index: 40;
}

.dev-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.45rem 1.25rem;
  background: #2a2112;
  color: #f6e2b3;
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.dev-banner strong {
  font-weight: 750;
}

.dev-banner a {
  color: #f6e2b3;
  text-decoration: none;
  border: 1px solid color-mix(in srgb, #f6e2b3 45%, transparent);
  border-radius: 999px;
  padding: 0.2rem 0.7rem;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.dev-banner a:hover {
  background: color-mix(in srgb, #f6e2b3 12%, transparent);
  color: #fff8e8;
}

/* --- Header --------------------------------------------------------------- */
.site-header {
  position: relative;
  background: var(--header-bg);
  color: var(--header-fg);
  border-bottom: 1px solid var(--header-border);
  backdrop-filter: blur(18px) saturate(1.35);
  -webkit-backdrop-filter: blur(18px) saturate(1.35);
}

.brand-rail {
  height: 3px;
  background: var(--header-gradient);
  position: relative;
}

body[data-v3="example"] .brand-rail::after {
  content: "";
  position: absolute;
  inset: auto 0 -2px 0;
  height: 1px;
  background: var(--geo-stripe);
  opacity: 0.85;
  pointer-events: none;
}

.header-inner {
  max-width: var(--container-width);
  margin-inline: auto;
  padding: 0.85rem 1.25rem;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--header-fg);
  min-width: 0;
}

.logo:hover {
  color: var(--header-fg);
}

.logo-mark {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border-radius: var(--mark-radius);
  background: var(--mark-gradient);
  color: var(--on-primary);
  box-shadow:
    0 0 0 1px color-mix(in srgb, white 18%, transparent) inset,
    0 10px 22px -14px var(--color-primary);
}

body[data-v3="example"] .logo-mark {
  width: 44px;
  height: 44px;
  box-shadow:
    0 0 0 1px color-mix(in srgb, white 24%, transparent) inset,
    0 14px 28px -16px color-mix(in srgb, var(--color-primary) 70%, black),
    0 0 28px -10px var(--hero-glow-2);
}

body[data-v3="example"] .logo-mark svg {
  width: 24px;
  height: 24px;
}

.logo-mark svg {
  width: 22px;
  height: 22px;
}

.logo-lockup {
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
  min-width: 0;
}

.logo-wordmark {
  font-family: var(--font-display);
  font-weight: var(--font-weight-display);
  font-style: var(--wordmark-style);
  font-size: clamp(1.05rem, 2.2vw, 1.35rem);
  letter-spacing: var(--wordmark-tracking);
  text-transform: var(--wordmark-transform);
  line-height: 1;
  white-space: nowrap;
}

.logo-domain {
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  line-height: 1.2;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-panel {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.site-nav ul {
  display: flex;
  list-style: none;
  padding: 0;
  gap: 0.15rem;
}

.site-nav a:not(.btn) {
  color: var(--header-fg);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 600;
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  transition: background var(--transition), color var(--transition);
}

.site-nav a:not(.btn):hover,
.site-nav a.nav-active {
  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
  color: var(--color-primary);
}

.header-cta {
  margin-left: 0.35rem;
  padding: 0.55rem 1rem;
  font-size: 0.88rem;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--header-border);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--color-surface) 70%, transparent);
  position: relative;
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  position: absolute;
  left: 11px;
  right: 11px;
  height: 1.5px;
  background: var(--header-fg);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle span:nth-child(1) { transform: translateY(-6px); }
.nav-toggle span:nth-child(2) { transform: translateY(0); }
.nav-toggle span:nth-child(3) { transform: translateY(6px); }

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(0) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(0) rotate(-45deg);
}

/* --- Layout --------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.eyebrow-dot {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--color-accent) 18%, transparent);
}

/* --- Hero / puzzle stage -------------------------------------------------- */
.hero,
.rules-section,
.contact-section {
  scroll-margin-top: 7.25rem;
}

.hero {
  position: relative;
  isolation: isolate;
  overflow: clip;
  padding: 2.75rem 0 4.25rem;
}

.hero-atmosphere {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(720px 340px at 8% -10%, var(--hero-glow), transparent 68%),
    radial-gradient(560px 300px at 100% 0%, var(--hero-glow-2), transparent 62%);
}

body[data-motif="heritage"] .hero-atmosphere {
  background:
    radial-gradient(680px 320px at 0% 0%, var(--hero-glow), transparent 70%),
    radial-gradient(420px 240px at 100% 8%, var(--hero-glow-2), transparent 70%),
    repeating-linear-gradient(
      -36deg,
      transparent 0 12px,
      color-mix(in srgb, var(--color-accent) 14%, transparent) 12px 13px
    );
}

body[data-v3="example"][data-motif="heritage"] .hero-copy h1 {
  text-shadow: 0 1px 0 color-mix(in srgb, white 40%, transparent);
}

body[data-motif="optimism"] .hero-atmosphere::after {
  content: "";
  position: absolute;
  width: min(460px, 70vw);
  height: min(460px, 70vw);
  right: -6vw;
  top: -18vw;
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 50%, var(--hero-glow-2), transparent 62%);
  box-shadow: inset 0 0 0 18px color-mix(in srgb, var(--color-accent) 12%, transparent);
}

body[data-v3="example"][data-motif="optimism"] .chip {
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--color-surface) 72%, transparent);
  box-shadow: 0 1px 0 color-mix(in srgb, white 50%, transparent) inset;
}

body[data-motif="elegance"] .hero-atmosphere {
  background:
    linear-gradient(
      to bottom,
      transparent 0 88px,
      color-mix(in srgb, var(--color-primary) 12%, transparent) 88px 89px,
      transparent 89px
    ),
    radial-gradient(640px 280px at 70% -20%, var(--hero-glow), transparent 70%),
    radial-gradient(280px 180px at 0% 20%, var(--hero-glow-2), transparent 70%);
}

body[data-v3="example"][data-motif="elegance"] .eyebrow-dot {
  border-radius: 1px;
  transform: rotate(45deg);
}

body[data-motif="industrial"] .hero-atmosphere {
  background:
    linear-gradient(to right, color-mix(in srgb, var(--color-text) 7%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--color-text) 7%, transparent) 1px, transparent 1px),
    radial-gradient(480px 220px at 92% 0%, var(--hero-glow), transparent 70%);
  background-size: 56px 56px, 56px 56px, auto;
}

.hero-inner {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.hero-copy {
  max-width: 40rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.85rem;
}

.hero-copy h1 {
  font-family: var(--font-display);
  font-weight: var(--font-weight-display);
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  letter-spacing: -0.035em;
  line-height: 0.98;
  color: var(--color-text);
}

.lede {
  font-size: clamp(1.02rem, 1.6vw, 1.2rem);
  color: var(--color-text-muted);
  max-width: 38rem;
  line-height: 1.55;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.25rem;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--color-surface) 80%, transparent);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.82rem;
  font-weight: 650;
}

.chip strong {
  color: var(--color-primary);
  font-weight: 750;
}

.chip-timer {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.timer-icon {
  color: var(--color-accent);
  font-style: normal;
}

.stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(168px, 220px);
  gap: 1.25rem;
  align-items: start;
  padding: 1rem;
  background: var(--stage-bg);
  border: 1px solid color-mix(in srgb, var(--color-border) 75%, transparent);
  border-radius: var(--radius-lg);
  box-shadow:
    var(--shadow-stage),
    inset 0 1px 0 color-mix(in srgb, white 45%, transparent);
}

body[data-v3="example"] .stage {
  background: color-mix(in srgb, var(--stage-bg) 92%, transparent);
  backdrop-filter: blur(14px) saturate(1.2);
  -webkit-backdrop-filter: blur(14px) saturate(1.2);
}

.stage-board,
.puzzle-board-wrapper {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 0.85rem;
  min-width: 0;
  width: 100%;
}

.puzzle-board {
  width: 100%;
  max-width: 640px;
  align-self: center;
  aspect-ratio: 1;
  background: var(--color-surface);
  border-radius: calc(var(--radius-md) - 2px);
  box-shadow:
    inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 35%, var(--color-border)),
    0 18px 40px -28px color-mix(in srgb, var(--color-primary) 70%, black);
  position: relative;
  overflow: hidden;
}

.stage-controls {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  padding: 0.35rem 0.15rem 0.15rem;
}

.controls-label {
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* --- Puzzle grids --------------------------------------------------------- */
.sudoku-grid,
.suguru-grid,
.shikaku-grid,
.binary-grid {
  width: 100%;
  height: 100%;
}

.sudoku-grid {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
}

.sudoku-cell,
.suguru-cell,
.shikaku-cell,
.futoshiki-cell,
.binary-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-puzzle);
  font-variant-numeric: tabular-nums;
  font-weight: var(--font-weight-puzzle);
  font-feature-settings: "tnum", "lnum";
  font-synthesis: none;
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: geometricPrecision;
  color: var(--color-text);
  user-select: none;
  transition: background var(--transition), box-shadow var(--transition), color var(--transition);
}

.sudoku-cell {
  font-size: clamp(0.95rem, 2.4vw, 1.45rem);
  border: 1px solid color-mix(in srgb, var(--color-border) 85%, var(--color-primary));
  cursor: pointer;
}

.sudoku-cell.given {
  color: var(--color-primary);
  font-weight: var(--font-weight-puzzle-given);
  background: color-mix(in srgb, var(--color-primary) 7%, var(--color-surface));
  cursor: default;
}

.sudoku-cell.highlight {
  background: color-mix(in srgb, var(--color-accent) 12%, var(--color-surface));
}

.sudoku-cell.selected,
.sudoku-cell:focus-visible {
  background: color-mix(in srgb, var(--color-accent) 24%, var(--color-surface));
  box-shadow: inset 0 0 0 2px var(--focus-ring);
  outline: none;
  z-index: 1;
}

.sudoku-cell.error {
  color: var(--color-error);
  background: color-mix(in srgb, var(--color-error) 14%, var(--color-surface));
}

.sudoku-cell.correct {
  background: color-mix(in srgb, var(--color-success) 16%, var(--color-surface));
}

.sudoku-cell:nth-child(3n) {
  border-right: 2px solid color-mix(in srgb, var(--color-primary) 70%, var(--color-border));
}

.sudoku-cell:nth-child(n+19):nth-child(-n+27),
.sudoku-cell:nth-child(n+46):nth-child(-n+54) {
  border-bottom: 2px solid color-mix(in srgb, var(--color-primary) 70%, var(--color-border));
}

@media (hover: hover) {
  .sudoku-cell:not(.given):hover {
    background: color-mix(in srgb, var(--color-accent) 14%, var(--color-surface));
  }
}

.killer-sum {
  position: absolute;
  top: 2px;
  left: 3px;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  line-height: 1;
  color: var(--color-accent);
  z-index: 2;
  pointer-events: none;
}

.suguru-grid { display: grid; }

.suguru-cell {
  font-size: clamp(0.95rem, 2.6vw, 1.45rem);
  border: 1px solid color-mix(in srgb, var(--color-border) 80%, transparent);
  cursor: pointer;
}

.suguru-cell.given {
  color: var(--color-primary);
  font-weight: var(--font-weight-puzzle-given);
  cursor: default;
}

.suguru-cell[data-border-top="thick"] { border-top: 2.5px solid var(--color-text); }
.suguru-cell[data-border-right="thick"] { border-right: 2.5px solid var(--color-text); }
.suguru-cell[data-border-bottom="thick"] { border-bottom: 2.5px solid var(--color-text); }
.suguru-cell[data-border-left="thick"] { border-left: 2.5px solid var(--color-text); }

.suguru-cell[data-region="0"] { background: color-mix(in srgb, var(--color-primary) 8%, var(--color-surface)); }
.suguru-cell[data-region="1"] { background: color-mix(in srgb, var(--color-accent) 14%, var(--color-surface)); }
.suguru-cell[data-region="2"] { background: color-mix(in srgb, var(--color-success) 10%, var(--color-surface)); }
.suguru-cell[data-region="3"] { background: color-mix(in srgb, #7a5af8 8%, var(--color-surface)); }
.suguru-cell[data-region="4"] { background: color-mix(in srgb, #e07a3d 10%, var(--color-surface)); }
.suguru-cell[data-region="5"] { background: color-mix(in srgb, #2a9d8f 10%, var(--color-surface)); }
.suguru-cell[data-region="6"] { background: color-mix(in srgb, #8d6e63 10%, var(--color-surface)); }

.suguru-cell.selected,
.suguru-cell:focus-visible {
  background: color-mix(in srgb, var(--color-accent) 32%, var(--color-surface)) !important;
  box-shadow: inset 0 0 0 2px var(--focus-ring);
  outline: none;
  z-index: 1;
}

.suguru-cell.error { color: var(--color-error) !important; }

.shikaku-grid {
  display: grid;
  cursor: crosshair;
}

.shikaku-cell {
  border: 1px solid var(--color-border);
  font-size: clamp(0.85rem, 2.2vw, 1.2rem);
  font-weight: var(--font-weight-puzzle-given);
  color: var(--color-primary);
  position: relative;
}

.shikaku-cell.has-number::after {
  content: "";
  position: absolute;
  inset: 18%;
  border: 1.5px solid var(--color-accent);
  border-radius: 50%;
  pointer-events: none;
}

.shikaku-rect {
  position: absolute;
  border: 2.5px solid var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
  pointer-events: none;
  z-index: 2;
}

.shikaku-cell.in-rect,
.shikaku-cell.selected {
  background: color-mix(in srgb, var(--color-accent) 16%, var(--color-surface));
}

.futoshiki-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  padding: 4%;
}

.futoshiki-grid { display: grid; }

.futoshiki-cell {
  font-size: clamp(1rem, 2.8vw, 1.6rem);
  border: 1.5px solid var(--color-border);
  cursor: pointer;
  background: var(--color-surface);
}

.futoshiki-cell.given {
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 7%, var(--color-surface));
  cursor: default;
}

.futoshiki-cell.selected,
.futoshiki-cell:focus-visible {
  background: color-mix(in srgb, var(--color-accent) 22%, var(--color-surface));
  box-shadow: inset 0 0 0 2px var(--focus-ring);
  outline: none;
}

.futoshiki-cell.error {
  color: var(--color-error);
  background: color-mix(in srgb, var(--color-error) 12%, var(--color-surface));
}

.futoshiki-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(0.8rem, 2vw, 1.15rem);
  font-weight: 800;
  color: var(--color-accent);
  user-select: none;
}

.binary-grid { display: grid; }

.binary-cell {
  font-family: var(--font-mono);
  font-size: clamp(0.85rem, 2.4vw, 1.35rem);
  font-weight: var(--font-weight-puzzle);
  border: 1px solid var(--color-border);
  cursor: pointer;
  color: var(--color-text-muted);
}

.binary-cell.given {
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 8%, var(--color-surface));
  cursor: default;
}

.binary-cell[data-value="0"] { color: var(--color-primary); }
.binary-cell[data-value="1"] { color: var(--color-accent); }

.binary-cell.error {
  background: color-mix(in srgb, var(--color-error) 14%, var(--color-surface));
}

.binary-cell.correct {
  background: color-mix(in srgb, var(--color-success) 14%, var(--color-surface));
}

.binary-cell:focus-visible {
  box-shadow: inset 0 0 0 2px var(--focus-ring);
  outline: none;
}

.puzzle-loading {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  color: var(--color-text-muted);
  font-size: 0.92rem;
}

.puzzle-feedback {
  width: 100%;
  max-width: 640px;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-weight: 650;
  font-size: 0.92rem;
  text-align: center;
  animation: rise 220ms var(--transition);
}

.puzzle-feedback.success {
  background: color-mix(in srgb, var(--color-success) 12%, var(--color-surface));
  color: var(--color-success);
  border: 1px solid color-mix(in srgb, var(--color-success) 45%, transparent);
}

.puzzle-feedback.error {
  background: color-mix(in srgb, var(--color-error) 10%, var(--color-surface));
  color: var(--color-error);
  border: 1px solid color-mix(in srgb, var(--color-error) 40%, transparent);
}

@keyframes rise {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Controls ------------------------------------------------------------- */
.numpad {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.45rem;
}

.numpad:empty { display: none; }

.numpad-btn {
  min-height: 46px;
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 55%, var(--color-surface));
  color: var(--color-text);
  font-family: var(--font-puzzle);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum", "lnum";
  font-size: 1.05rem;
  font-weight: var(--font-weight-puzzle-given);
  border-radius: var(--radius-sm);
  transition: transform var(--transition), background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.numpad-btn:hover {
  border-color: var(--color-primary);
  transform: translateY(-1px);
  box-shadow: 0 8px 16px -12px var(--color-primary);
}

.numpad-btn:active { transform: translateY(0); }

.numpad-btn.erase {
  grid-column: 1 / -1;
  font-family: var(--font-body);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.numpad-hint {
  font-size: 0.88rem;
  line-height: 1.45;
  color: var(--color-text-muted);
}

.control-buttons {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 46px;
  padding: 0.7rem 1.15rem;
  border-radius: var(--radius-btn);
  border: 1px solid transparent;
  font-weight: 680;
  font-size: 0.92rem;
  letter-spacing: 0.01em;
  text-decoration: none;
  white-space: nowrap;
  transition: transform var(--transition), background var(--transition), border-color var(--transition), box-shadow var(--transition), color var(--transition);
}

.btn:hover { text-decoration: none; }

.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--color-cta);
  color: var(--color-cta-fg);
  border-color: transparent;
  box-shadow: 0 10px 22px -14px var(--color-cta);
}

body[data-v3="example"] .btn-primary {
  background: linear-gradient(
    165deg,
    color-mix(in srgb, var(--color-cta) 92%, white) 0%,
    var(--color-cta) 48%,
    color-mix(in srgb, var(--color-cta) 88%, black) 100%
  );
  box-shadow:
    0 1px 0 color-mix(in srgb, white 28%, transparent) inset,
    0 14px 28px -14px color-mix(in srgb, var(--color-cta) 75%, black);
}

body[data-v3="example"] .header-cta.btn-primary {
  font-weight: 720;
  letter-spacing: 0.02em;
}

.btn-primary:hover {
  background: color-mix(in srgb, var(--color-cta) 86%, white);
  color: var(--color-cta-fg);
  transform: translateY(-1px);
  box-shadow: 0 16px 28px -16px var(--color-cta);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 6%, transparent);
  transform: translateY(-1px);
}

.control-buttons .btn { width: 100%; }

/* --- Rules ---------------------------------------------------------------- */
.rules-section,
.contact-section {
  padding: 4.5rem 0;
}

.rules-section {
  background: color-mix(in srgb, var(--color-surface) 78%, var(--color-secondary));
}

.section-heading {
  max-width: 40rem;
  margin-bottom: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.section-heading h2,
.contact-copy h2 {
  font-family: var(--font-display);
  font-weight: var(--font-weight-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  letter-spacing: -0.03em;
  line-height: 1.05;
}

.section-intro,
.contact-copy p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  max-width: 46rem;
}

.rules-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.surface-card {
  background: var(--color-surface);
  border: 1px solid color-mix(in srgb, var(--color-border) 80%, transparent);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.4rem 1.35rem;
  box-shadow: var(--shadow-card);
}

.surface-card h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: var(--font-weight-display);
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.step-list,
.tip-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.step-list { counter-reset: step; }

.step-list li,
.tip-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.75rem;
  align-items: start;
  line-height: 1.5;
  font-size: 0.98rem;
}

.step-list li::before {
  counter-increment: step;
  content: counter(step);
  width: 1.7rem;
  height: 1.7rem;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--color-primary) 12%, var(--color-surface));
  color: var(--color-primary);
  font-size: 0.78rem;
  font-weight: 750;
}

.tip-list li::before {
  content: "";
  width: 0.45rem;
  height: 0.45rem;
  margin-top: 0.5rem;
  border-radius: 50%;
  background: var(--color-accent);
}

/* --- Contact -------------------------------------------------------------- */
.contact-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 2rem;
  align-items: start;
}

.contact-copy {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  position: sticky;
  top: 7.5rem;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.8rem 0.9rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 45%, var(--color-surface));
  color: var(--color-text);
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
  resize: vertical;
}

.form-group input:hover,
.form-group textarea:hover {
  border-color: color-mix(in srgb, var(--color-primary) 45%, var(--color-border));
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--focus-ring) 28%, transparent);
  background: var(--color-surface);
}

.form-footer {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  flex-wrap: wrap;
}

.form-note {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  max-width: 28rem;
  line-height: 1.45;
}

.form-submit-feedback {
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--color-success) 10%, var(--color-surface));
  border: 1px solid color-mix(in srgb, var(--color-success) 40%, transparent);
  color: var(--color-success);
  font-size: 0.92rem;
  font-weight: 600;
  line-height: 1.45;
}

.form-submit-feedback strong { font-weight: 750; }

/* --- Footer --------------------------------------------------------------- */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-fg);
  padding: 3.25rem 0 2rem;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 2rem;
  align-items: start;
}

.footer-lockup {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
}

.footer-mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: var(--mark-gradient);
  color: var(--on-primary);
}

.footer-mark svg { width: 18px; height: 18px; }

.footer-wordmark {
  display: block;
  font-family: var(--font-display);
  font-weight: var(--font-weight-display);
  font-style: var(--wordmark-style);
  letter-spacing: var(--wordmark-tracking);
  text-transform: var(--wordmark-transform);
  font-size: 1.2rem;
  line-height: 1;
}

.footer-domain {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--footer-muted);
}

.footer-tagline {
  color: var(--footer-muted);
  max-width: 28rem;
  font-size: 0.95rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding-top: 0.35rem;
}

.footer-links a,
.footer-network a {
  color: var(--footer-fg);
  text-decoration: none;
  font-weight: 600;
  width: fit-content;
}

.footer-links a:hover,
.footer-network a:hover {
  color: var(--color-accent-light);
}

.footer-network {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.45rem;
  padding-top: 0.35rem;
}

.footer-network a {
  border-bottom: 1px solid color-mix(in srgb, var(--footer-fg) 35%, transparent);
  padding-bottom: 0.1rem;
}

.footer-copy {
  color: var(--footer-muted);
  font-size: 0.82rem;
}

/* --- Shared states -------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (forced-colors: active) {
  .sudoku-cell,
  .suguru-cell,
  .binary-cell,
  .futoshiki-cell,
  .btn {
    forced-color-adjust: auto;
  }
}

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

/* --- Responsive ----------------------------------------------------------- */
@media (max-width: 980px) {
  .nav-toggle { display: inline-flex; }

  .nav-panel {
    display: none;
  }

  .site-nav.open .nav-panel {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    padding: 0.75rem 1.25rem 1.1rem;
    background: var(--color-surface);
    border-bottom: 1px solid var(--header-border);
    box-shadow: 0 24px 40px -28px rgba(0, 0, 0, 0.45);
    gap: 0.25rem;
  }

  .site-nav.open ul {
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav.open a:not(.btn) {
    padding: 0.75rem 0.7rem;
  }

  .header-cta {
    margin: 0.4rem 0 0;
    width: 100%;
  }

  .contact-copy { position: static; }
}

@media (max-width: 860px) {
  .stage {
    grid-template-columns: 1fr;
    padding: 0.75rem;
    gap: 1rem;
  }

  .stage-controls { padding: 0 0.15rem 0.25rem; }

  .control-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .btn-check { grid-column: 1 / -1; }

  .rules-grid,
  .contact-layout,
  .form-row,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero { padding: 2rem 0 3rem; }

  .rules-section,
  .contact-section { padding: 3.25rem 0; }
}

@media (max-width: 420px) {
  .logo-domain { display: none; }
  .dev-banner { font-size: 0.68rem; letter-spacing: 0.03em; }
  .hero-copy h1 { font-size: 2.15rem; }
}

/* Daily pages: readable ink, compact header, no horizontal scroll. */
html,
body {
  overflow-x: clip;
  max-width: 100%;
}

.eyebrow {
  color: var(--color-primary-ink, var(--color-text));
}

.header-inner {
  min-width: 0;
  flex-wrap: wrap;
  row-gap: 0.35rem;
}

.site-nav {
  min-width: 0;
  margin-left: auto;
}

.site-nav ul {
  flex-wrap: wrap;
  justify-content: flex-end;
}

.site-nav a:not(.btn):hover,
.site-nav a[aria-current="page"] {
  background: color-mix(in srgb, var(--header-fg) 14%, transparent);
  color: var(--header-fg);
}

.recent-section,
.activity-section,
.archive-section,
.advanced-section {
  padding: 1.25rem 0 2.5rem;
}

.daily-list,
.activity-list {
  list-style: none;
  padding: 0;
  margin: 0.85rem 0 0;
}

.daily-list {
  display: grid;
  gap: 0.75rem;
}

.daily-row {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  background: var(--color-surface);
  min-width: 0;
}

.daily-row > a {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
  color: var(--color-text);
  font-weight: 700;
  text-decoration: none;
}

.daily-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(7.5rem, 1fr));
  gap: 0.45rem 0.8rem;
  margin: 0.65rem 0 0;
}

.daily-stats dt {
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.daily-stats dd {
  margin: 0.12rem 0 0;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.activity-list {
  display: grid;
  gap: 0.45rem;
}

.activity-list li,
.daily-empty,
.activity-empty,
.niche-engine-empty {
  color: var(--color-text);
}

.activity-list time {
  color: var(--color-text-muted);
  margin-right: 0.35rem;
}

.pager {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.25rem;
}

.pager a,
.section-more a {
  color: var(--color-text);
  font-weight: 700;
}

.niche-tutorial,
.advanced-section section,
.niche-leaderboard,
#gridComments {
  margin-top: 1.25rem;
}

.advanced-section h1,
.advanced-section h2,
.rules-section h1,
.archive-section h1,
.contact-section h1,
.recent-section h2,
.activity-section h2 {
  color: var(--color-text);
}

@media (max-width: 980px) {
  .nav-toggle { display: none !important; }
  .nav-panel {
    display: flex !important;
    position: static;
    box-shadow: none;
    border: 0;
    padding: 0;
    background: transparent;
  }
  .site-nav ul,
  .site-nav.open ul {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: flex-end;
  }
}

@media (max-width: 420px) {
  .logo-wordmark {
    white-space: normal;
    font-size: clamp(0.95rem, 4.2vw, 1.15rem);
  }
}

.premium-section h1,
.premium-card h2 {
  color: var(--color-text);
}

.niche-premium-banner {
  margin: 0 0 1.25rem;
}

.premium-compare {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

@media (min-width: 720px) {
  .premium-compare {
    grid-template-columns: 1fr 1.15fr;
    align-items: stretch;
  }
}

.premium-card ul {
  margin: 0.75rem 0 0;
  padding-left: 1.1rem;
  color: var(--color-text-muted);
}

.premium-card li {
  margin: 0.35rem 0;
}

.premium-card--paid {
  border-color: color-mix(in srgb, var(--color-accent) 45%, var(--color-border));
}

.premium-tax {
  margin: 1rem 0 0;
  font-size: 0.92rem;
  color: var(--color-text-muted);
}

.premium-actions {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-top: 1rem;
}

.premium-annual {
  position: relative;
}

.premium-annual-badge {
  display: inline-block;
  margin-right: 0.35rem;
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  background: color-mix(in srgb, var(--color-accent) 22%, transparent);
  color: var(--color-primary-ink);
}

.premium-auth,
.premium-status {
  margin: 0.85rem 0 0;
  font-size: 0.92rem;
  color: var(--color-text-muted);
}

.premium-status--error {
  color: var(--color-error);
}

.niche-checkout-status {
  margin: 1rem 0 0;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-alt);
}

.niche-checkout-status h2 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}

.niche-checkout-status p {
  margin: 0;
  color: var(--color-text-muted);
}

.niche-checkout-status--success {
  border-color: color-mix(in srgb, var(--color-success) 55%, var(--color-border));
}

.niche-checkout-status--error {
  border-color: color-mix(in srgb, var(--color-error) 55%, var(--color-border));
}