/* ============================================================
   RUFT — Static Website Stylesheet
   Aesthetic: monospace + angular (A4 paper) + warm textile craft
   ============================================================ */

/* ── Reset & Base ────────────────────────────────────────── */

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

:root {
  /* Textile palette */
  --linen: #F5F0E8;
  --cream: #FAF7F2;
  --warm-gray: #E8E2D8;
  --terracotta: #C2703E;
  --terracotta-dark: #A85C30;
  --teal: #2A6B6B;
  --teal-dark: #1F5252;
  --dark-brown: #3A3226;
  --light-border: #CCC5B9;
  --gold: #FFD700;

  /* Typography */
  --font-mono: "IBM Plex Mono", "Fira Code", "JetBrains Mono", "Cascadia Code", "Consolas", monospace;

  /* Spacing (A4-like proportions) */
  --page-margin: 64px;
  --gap: 24px;
  --radius: 2px; /* angular, not rounded */
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-mono);
  background: var(--cream);
  color: var(--dark-brown);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

/* ── Container ───────────────────────────────────────────── */

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--gap);
}

/* ── A4 Page Effect ──────────────────────────────────────── */

.page,
.hero__page {
  display: flex;
  background: var(--cream);
  border: 1px solid var(--light-border);
  box-shadow: 4px 4px 0 rgba(58, 50, 38, 0.06);
  position: relative;
}

.page__margin,
.hero__margin {
  width: 48px;
  min-height: 100%;
  border-right: 2px solid #E2B8B0;
  background: repeating-linear-gradient(
    transparent,
    transparent 23px,
    var(--light-border) 23px,
    var(--light-border) 24px
  );
  flex-shrink: 0;
  position: relative;
}

.page__label {
  position: absolute;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  color: var(--light-border);
  font-weight: 600;
  letter-spacing: 0.05em;
}

.page__content,
.hero__content {
  flex: 1;
  padding: 48px 40px;
}

/* ── Header ──────────────────────────────────────────────── */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--cream);
  border-bottom: 1px solid var(--light-border);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo__icon {
  display: flex;
}

.logo__text {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--dark-brown);
}

.logo__text--sm {
  font-size: 1rem;
}

.nav {
  display: flex;
  gap: var(--gap);
}

.nav__link {
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  color: var(--dark-brown);
  opacity: 0.6;
  transition: opacity 0.2s;
  text-transform: lowercase;
}

.nav__link:hover {
  opacity: 1;
  color: var(--terracotta);
}

/* ── Hero ────────────────────────────────────────────────── */

.hero {
  padding-top: 96px;
  padding-bottom: 48px;
}

.hero__content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 32px;
}

.hero__top {
  display: flex;
  gap: 40px;
  align-items: flex-start;
  width: 100%;
}

.hero__grid {
  flex-shrink: 0;
}

.grid-demo {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 2px;
  width: 280px;
  aspect-ratio: 1;
}

.grid-demo__cell {
  aspect-ratio: 1;
  border: 1px solid var(--light-border);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.hero__intro {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-top: 8px;
}

.hero__icon {
  width: 80px;
  height: 80px;
  image-rendering: pixelated;
}

.hero__title {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hero__title-main {
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--dark-brown);
  line-height: 1;
}

.hero__title-sub {
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  color: var(--terracotta);
  text-transform: uppercase;
  font-weight: 500;
}

.hero__desc {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--dark-brown);
  opacity: 0.75;
  max-width: 480px;
}

.hero__cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero__palette {
  display: flex;
  gap: 6px;
  padding-top: 16px;
  border-top: 1px dashed var(--light-border);
  width: 100%;
}

.swatch {
  width: 24px;
  height: 24px;
  background: var(--c);
  border: 1px solid var(--light-border);
  transition: transform 0.15s;
}

.swatch:hover {
  transform: scale(1.3);
}

/* ── Buttons ─────────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
  text-transform: uppercase;
}

.btn--primary {
  background: var(--terracotta);
  color: var(--cream);
  border-color: var(--terracotta);
}

.btn--primary:hover {
  background: var(--terracotta-dark);
  border-color: var(--terracotta-dark);
}

.btn--outline {
  background: transparent;
  color: var(--teal);
  border-color: var(--teal);
}

.btn--outline:hover {
  background: var(--teal);
  color: var(--cream);
}

/* ── Sections ────────────────────────────────────────────── */

.section {
  padding: 48px 0;
}

.section--alt {
  background: var(--linen);
}

.section__title {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--dark-brown);
  margin-bottom: 32px;
  text-transform: uppercase;
  position: relative;
  padding-bottom: 12px;
}

.section__title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--terracotta);
}

.section__note {
  font-size: 0.8rem;
  color: var(--light-border);
  margin-bottom: 24px;
  font-style: italic;
}

/* ── About Cards ─────────────────────────────────────────── */

.about__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--gap);
}

.about__card {
  padding: 24px;
  border: 1px solid var(--light-border);
  background: var(--cream);
  transition: border-color 0.2s;
}

.about__card:hover {
  border-color: var(--terracotta);
}

.about__icon {
  margin-bottom: 16px;
}

.about__card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  text-transform: uppercase;
}

.about__card p {
  font-size: 0.8rem;
  line-height: 1.7;
  opacity: 0.8;
}

/* ── Mode Cards ──────────────────────────────────────────── */

.modes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--gap);
}

.mode-card {
  border: 2px solid var(--light-border);
  background: var(--cream);
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.mode-card:hover {
  box-shadow: 6px 6px 0 rgba(58, 50, 38, 0.08);
}

.mode-card--puzzle:hover {
  border-color: var(--terracotta);
}

.mode-card--zen:hover {
  border-color: var(--teal);
}

.mode-card__header {
  padding: 12px 20px;
  border-bottom: 1px solid var(--light-border);
}

.mode-card--puzzle .mode-card__header {
  background: var(--terracotta);
}

.mode-card--zen .mode-card__header {
  background: var(--teal);
}

.mode-card__tag {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--cream);
}

.mode-card__body {
  padding: 24px 20px;
}

.mode-card__body h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}

.mode-card__list li {
  font-size: 0.8rem;
  padding: 4px 0;
  padding-left: 20px;
  position: relative;
  opacity: 0.8;
}

.mode-card__list li::before {
  content: ">";
  position: absolute;
  left: 0;
  color: var(--terracotta);
  font-weight: 700;
}

.mode-card--zen .mode-card__list li::before {
  color: var(--teal);
}

/* ── Steps ───────────────────────────────────────────────── */

.steps {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.step {
  display: flex;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px dashed var(--light-border);
}

.step:last-child {
  border-bottom: none;
}

.step__num {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--terracotta);
  font-weight: 700;
  font-size: 1rem;
  color: var(--terracotta);
  flex-shrink: 0;
}

.step__text h3 {
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
  text-transform: uppercase;
}

.step__text p {
  font-size: 0.8rem;
  opacity: 0.8;
  line-height: 1.7;
}

/* ── Controls ────────────────────────────────────────────── */

.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.controls__heading {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 16px;
  color: var(--teal);
}

.controls__list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 14px;
  border: 1px solid var(--light-border);
  background: var(--cream);
  transition: border-color 0.2s;
}

.control:hover {
  border-color: var(--terracotta);
}

kbd {
  background: var(--dark-brown);
  color: var(--cream);
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  min-width: 48px;
  text-align: center;
  white-space: nowrap;
}

.control span {
  font-size: 0.8rem;
  opacity: 0.8;
}

/* ── Pattern Gallery ─────────────────────────────────────── */

.gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--gap);
}

.gallery__item {
  aspect-ratio: 1;
  border: 2px solid var(--light-border);
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
}

.gallery__item:hover {
  border-color: var(--terracotta);
  box-shadow: 4px 4px 0 rgba(58, 50, 38, 0.08);
}

.gallery__item canvas {
  width: 100%;
  height: 100%;
  display: block;
  image-rendering: pixelated;
}

.gallery__item::after {
  content: "click to regenerate";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 6px;
  background: rgba(58, 50, 38, 0.7);
  color: var(--cream);
  font-size: 0.6rem;
  text-align: center;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0;
  transition: opacity 0.2s;
}

.gallery__item:hover::after {
  opacity: 1;
}

/* ── Footer ──────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--light-border);
  padding: 24px 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer__left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.footer__copy {
  font-size: 0.75rem;
  opacity: 0.5;
}

.footer__links {
  display: flex;
  gap: 20px;
}

.footer__link {
  font-size: 0.8rem;
  opacity: 0.6;
  transition: opacity 0.2s;
  letter-spacing: 0.05em;
}

.footer__link:hover {
  opacity: 1;
  color: var(--terracotta);
}

/* ── Animations ──────────────────────────────────────────── */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero__title,
.hero__desc,
.hero__cta {
  animation: fadeIn 0.5s ease both;
}

.hero__desc { animation-delay: 0.1s; }
.hero__cta { animation-delay: 0.2s; }

/* ── Responsive ──────────────────────────────────────────── */

@media (max-width: 768px) {
  :root {
    --page-margin: 24px;
    --gap: 16px;
  }

  .nav {
    display: none;
  }

  .hero__top {
    flex-direction: column;
    gap: 24px;
  }

  .grid-demo {
    width: 100%;
    max-width: 280px;
  }

  .hero__title-main {
    font-size: 2.4rem;
  }

  .page__margin,
  .hero__margin {
    width: 28px;
  }

  .page__content,
  .hero__content {
    padding: 28px 20px;
  }

  .modes {
    grid-template-columns: 1fr;
  }

  .controls {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .gallery {
    grid-template-columns: repeat(2, 1fr);
  }

  .about__grid {
    grid-template-columns: 1fr;
  }

  .page__label {
    font-size: 0.6rem;
  }
}

@media (max-width: 480px) {
  .hero__title-main {
    font-size: 2rem;
    letter-spacing: 0.15em;
  }

  .hero__cta {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .gallery {
    grid-template-columns: 1fr;
  }

  .footer__inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

/* ── Print-like details ──────────────────────────────────── */

::selection {
  background: var(--terracotta);
  color: var(--cream);
}

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--linen);
}

::-webkit-scrollbar-thumb {
  background: var(--light-border);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--terracotta);
}