/* sim-ai.com — neubrutalist field manual */
:root {
  --terracotta: #b85c38;
  --sage: #7a9468;
  --amber: #d4a040;
  --ink: #1a1a1a;
  --grey-dark: #3a3632;
  --paper: #f8f4ec;
  --sepia: #f0e8d8;
  --bg: var(--sepia);
  --text: var(--ink);
  --border-thick: 4px;
  --headline: "Barlow Condensed", "Inter", system-ui, sans-serif;
  --body-font: "Source Sans 3", "Inter", system-ui, sans-serif;
  --mono: "Space Mono", ui-monospace, monospace;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--sepia);
  color: var(--ink);
  font-family: var(--body-font);
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.7;
  position: relative;
  overflow-x: hidden;
}

.paper-grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.6;
}

.paper-grain svg {
  width: 100%;
  height: 100%;
}

/* Menu dot */
.menu-dot {
  position: fixed;
  top: 1.6rem;
  right: 1.6rem;
  width: 44px;
  height: 44px;
  background: var(--paper);
  border: 3px solid var(--ink);
  z-index: 50;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.menu-dot:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--ink);
}

.menu-dot.is-open {
  background: var(--amber);
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}

.dot-line {
  width: 22px;
  height: 2px;
  background: var(--ink);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-dot.is-open .dot-line:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.menu-dot.is-open .dot-line:nth-child(2) {
  opacity: 0;
}

.menu-dot.is-open .dot-line:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Menu overlay */
.menu-overlay {
  position: fixed;
  inset: 0;
  background: rgba(240, 232, 216, 0.97);
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.22s ease;
}

.menu-overlay.is-open {
  opacity: 1;
}

.menu-nav {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: 2rem;
  background: var(--paper);
  border: var(--border-thick) solid var(--ink);
  box-shadow: 12px 12px 0 var(--ink);
}

.menu-link {
  font-family: var(--headline);
  font-weight: 700;
  font-size: clamp(20px, 2.4vw, 28px);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink);
  text-decoration: none;
  padding: 0.4rem 0.8rem;
  border-left: 4px solid transparent;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.menu-link:hover {
  border-left-color: var(--terracotta);
  background: rgba(184, 92, 56, 0.08);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  padding: 5rem 5vw 3rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 2;
}

.hero-inner {
  max-width: 940px;
  width: 100%;
  position: relative;
}

.hero-mark {
  position: relative;
  border: var(--border-thick) solid var(--ink);
  padding: 4rem 3rem;
  background: var(--paper);
  box-shadow: 12px 12px 0 var(--ink);
  text-align: center;
  margin-bottom: 2rem;
}

.hero-mark-corner {
  position: absolute;
  width: 28px;
  height: 28px;
  background: var(--amber);
  border: 3px solid var(--ink);
}

.hero-mark-corner--tl { top: -14px; left: -14px; }
.hero-mark-corner--tr { top: -14px; right: -14px; background: var(--terracotta); }
.hero-mark-corner--bl { bottom: -14px; left: -14px; background: var(--sage); }
.hero-mark-corner--br { bottom: -14px; right: -14px; }

.hero-title {
  font-family: var(--headline);
  font-weight: 800;
  font-size: clamp(64px, 13vw, 180px);
  letter-spacing: 0.02em;
  line-height: 0.92;
  color: var(--ink);
  text-transform: uppercase;
  margin-bottom: 1.6rem;
}

.hero-subtitle {
  font-family: var(--body-font);
  font-weight: 400;
  font-size: clamp(16px, 1.7vw, 20px);
  color: var(--grey-dark);
  max-width: 50ch;
  margin: 0 auto 2rem;
  line-height: 1.55;
}

.hero-stamp {
  display: inline-flex;
  gap: 1.2rem;
  border: 2px solid var(--ink);
  padding: 0.45rem 1rem;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink);
  background: var(--sepia);
}

.stamp-no {
  color: var(--terracotta);
  font-weight: 700;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
  justify-content: center;
  margin-top: 2rem;
}

.meta-item {
  display: inline-flex;
  flex-direction: column;
  gap: 0.2rem;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.meta-key {
  color: var(--terracotta);
  font-weight: 700;
}

.meta-val {
  color: var(--grey-dark);
}

.hero-scroll {
  margin-top: 3rem;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: lowercase;
  color: var(--grey-dark);
  animation: scroll-pulse 2.6s ease-in-out infinite;
}

/* Manual */
.manual {
  position: relative;
  z-index: 2;
  padding: 4rem 5vw 6rem;
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 4rem;
}

.lesson {
  background: var(--paper);
  border: var(--border-thick) solid var(--ink);
  box-shadow: 10px 10px 0 var(--ink);
  position: relative;
  overflow: hidden;
}

.lesson-header {
  display: flex;
  align-items: baseline;
  gap: 1.4rem;
  padding: 1.2rem 1.6rem;
  border-bottom: var(--border-thick) solid var(--ink);
  font-family: var(--headline);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.lesson-header--terracotta { background: var(--terracotta); color: var(--paper); }
.lesson-header--sage { background: var(--sage); color: var(--paper); }
.lesson-header--amber { background: var(--amber); color: var(--ink); }
.lesson-header--ink { background: var(--ink); color: var(--paper); }

.lesson-num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(14px, 1.4vw, 17px);
  letter-spacing: 0.16em;
  padding: 0.2rem 0.6rem;
  background: rgba(255, 255, 255, 0.18);
  border: 2px solid currentColor;
}

.lesson-header--amber .lesson-num {
  background: rgba(26, 26, 26, 0.12);
}

.lesson-title {
  font-size: clamp(20px, 2.6vw, 30px);
  flex: 1;
  line-height: 1.05;
}

.lesson-body {
  padding: 2rem 2.4rem 2.4rem;
}

.lesson-lede {
  font-size: clamp(17px, 1.9vw, 22px);
  line-height: 1.55;
  margin-bottom: 1.6rem;
  color: var(--ink);
}

.lesson-lede strong,
.lesson-after strong {
  color: var(--terracotta);
}

.lesson-after {
  margin-top: 1.4rem;
  font-style: italic;
  color: var(--grey-dark);
}

/* Diagram */
.diagram {
  margin: 1.5rem 0 0.5rem;
  padding: 1.2rem;
  background: var(--sepia);
  border: 2px solid var(--ink);
}

.diagram-svg {
  width: 100%;
  height: auto;
  max-height: 240px;
}

.diagram-caption {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--grey-dark);
  margin-top: 0.6rem;
  text-align: center;
}

/* Bullet list */
.bullet-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin: 1.4rem 0;
  padding-left: 0;
}

.bullet-list li {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  padding-bottom: 0.6rem;
  border-bottom: 1px dashed rgba(58, 54, 50, 0.3);
}

.bullet-num {
  font-family: var(--mono);
  font-weight: 700;
  color: var(--sage);
  min-width: 2.6em;
}

.bullet-text strong {
  color: var(--terracotta);
}

/* Callout */
.callout {
  margin-top: 1.4rem;
  padding: 1.2rem 1.4rem;
  border: 3px solid var(--ink);
  background: var(--sepia);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  position: relative;
}

.callout--warning {
  background: rgba(212, 160, 64, 0.18);
  border-color: var(--ink);
}

.callout-tag {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--terracotta);
  display: inline-block;
  width: fit-content;
  border-bottom: 2px solid var(--terracotta);
  padding-bottom: 2px;
}

.callout-text em {
  font-style: italic;
  color: var(--terracotta);
}

/* Comparison grid */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.2rem;
  margin: 1.4rem 0 0.4rem;
}

.comparison-cell {
  border: 3px solid var(--ink);
  padding: 1.2rem;
  position: relative;
}

.comparison-cell--reality {
  background: rgba(184, 92, 56, 0.12);
}

.comparison-cell--sim {
  background: rgba(122, 148, 104, 0.16);
}

.comparison-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  background: var(--ink);
  color: var(--paper);
  padding: 0.25rem 0.6rem;
  margin-bottom: 0.8rem;
}

.comparison-list {
  list-style: square;
  padding-left: 1.4rem;
  font-family: var(--body-font);
  font-size: 15px;
  color: var(--grey-dark);
}

.comparison-list li {
  margin-bottom: 0.4rem;
}

/* Method grid */
.method-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 0.5rem;
}

.method-card {
  border: 3px solid var(--ink);
  background: var(--sepia);
  padding: 1.2rem 1.2rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.method-card:hover {
  transform: translate(-3px, -3px);
  box-shadow: 6px 6px 0 var(--ink);
  background: var(--paper);
}

.method-card.is-active {
  background: var(--amber);
  transform: translate(-3px, -3px);
  box-shadow: 6px 6px 0 var(--ink);
}

.method-num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--terracotta);
}

.method-name {
  font-family: var(--headline);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.method-text {
  font-size: 14px;
  color: var(--grey-dark);
  line-height: 1.5;
}

/* Exercise board */
.exercise-board {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 1.4rem;
}

.exercise-step {
  border: 3px solid var(--ink);
  padding: 1.2rem;
  background: var(--paper);
  position: relative;
  transition: background 0.2s ease;
}

.exercise-step::before {
  content: "";
  position: absolute;
  inset: -3px;
  border: 1px dashed rgba(26, 26, 26, 0.18);
  pointer-events: none;
}

.exercise-step:hover {
  background: rgba(212, 160, 64, 0.18);
}

.step-num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--sage);
  margin-bottom: 0.6rem;
  display: inline-block;
}

.step-text {
  font-size: 15px;
  color: var(--ink);
}

.step-text strong {
  color: var(--terracotta);
}

/* Closing */
.signoff {
  font-family: var(--headline);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--terracotta);
  margin: 1.6rem 0 0.8rem;
}

.closing-line {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--grey-dark);
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.line-mark {
  font-size: 18px;
  color: var(--ink);
}

/* Colophon */
.colophon {
  background: var(--ink);
  color: var(--paper);
  padding: 2.2rem 5vw;
  position: relative;
  z-index: 2;
}

.colophon-inner {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.4rem;
}

.colophon-mark {
  font-family: var(--headline);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.colophon-text {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: lowercase;
  color: var(--paper);
  opacity: 0.8;
}

.colophon-stamp {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--terracotta);
}

/* Reveal */
.lesson {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.85s ease, transform 0.85s ease;
}

.lesson.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes scroll-pulse {
  0%, 100% { opacity: 0.5; transform: translateY(0); }
  50% { opacity: 1; transform: translateY(4px); }
}

@media (max-width: 720px) {
  .comparison-grid {
    grid-template-columns: 1fr;
  }
  .colophon-inner {
    flex-direction: column;
    gap: 0.8rem;
    text-align: center;
  }
  .hero-mark {
    padding: 2.5rem 1.5rem;
  }
}