/* ===================== FONT ===================== */
@font-face {
  font-family: "Geist";
  src: url("https://cdn.jsdelivr.net/fontsource/fonts/geist:vf@5.3.0/latin-wght-normal.woff2") format("woff2-variations");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Geist Mono";
  src: url("https://cdn.jsdelivr.net/fontsource/fonts/geist-mono:vf@5.3.0/latin-wght-normal.woff2") format("woff2-variations");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

/* ===================== TOKENS ===================== */
:root {
  --bg: #F7F8FC;
  --surface: #FFFFFF;
  --text: #101322;
  --text-secondary: #62687B;
  --accent: #5145E5;
  --accent-contrast: #FFFFFF;
  --highlight: #B9FBC0;
  --border: #E4E7F0;
  --dark-bg: #101322;
  --dark-surface: #1A1E33;
  --dark-text: #F2F3F8;
  --dark-text-secondary: #9BA0B5;
  --dark-border: #2B3050;

  --font-sans: "Geist", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "Geist Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius-sm: 4px;
  --radius-md: 8px;
  --header-h: 64px;
  --max-w: 1180px;
}

/* ===================== RESET ===================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
h1, h2, h3, p, ul, figure { margin: 0; }
ul { padding: 0; list-style: none; }
a { color: inherit; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
input, textarea { font: inherit; }

.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  z-index: 200;
}
.skip-link:focus { left: 16px; top: 16px; }

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

/* ===================== BUTTONS ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: #423af0; }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-ghost-light {
  color: var(--dark-text);
  border-color: var(--dark-border);
}
.btn-ghost-light:hover { border-color: var(--highlight); color: var(--highlight); }

/* ===================== WORDMARK ("Il nodo") ===================== */
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text);
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.01em;
}
.wordmark-mark { color: var(--accent); flex-shrink: 0; }
.wordmark-footer { color: var(--dark-text); }
.wordmark-footer .wordmark-mark { color: var(--highlight); }

/* ===================== HEADER ===================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 248, 252, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 24px;
}
.main-nav {
  display: flex;
  gap: 28px;
  margin-left: auto;
  font-size: 15px;
  font-weight: 500;
}
.main-nav a { text-decoration: none; color: var(--text-secondary); }
.main-nav a:hover { color: var(--text); }
.header-cta { margin-left: 8px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  margin-left: auto;
}
.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
}

.mobile-nav[hidden] { display: none; }
.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px 24px 20px;
  border-top: 1px solid var(--border);
  background: var(--surface);
}
.mobile-nav a {
  padding: 12px 0;
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  border-bottom: 1px solid var(--border);
}
.mobile-nav a.btn { margin-top: 14px; width: 100%; border-bottom: none; padding: 12px 22px; }
.mobile-nav a.btn-primary { color: #fff; }

@media (max-width: 820px) {
  .main-nav, .header-cta { display: none; }
  .nav-toggle { display: flex; }
}

/* ===================== HERO ===================== */
.hero { padding: 64px 0 56px; }
.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 48px;
  align-items: center;
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin: 0 0 14px;
}
.hero h1 {
  font-size: clamp(32px, 4.2vw, 48px);
  line-height: 1.12;
  font-weight: 700;
  letter-spacing: -0.015em;
  margin: 0 0 18px;
}
.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 48ch;
  margin: 0 0 28px;
}
.hero-ctas { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 14px; }
.microcopy { font-size: 14px; color: var(--text-secondary); }

.hero-visual {
  position: relative;
  min-height: 320px;
}
.hv-card {
  position: absolute;
  width: 200px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  box-shadow: 0 10px 24px -14px rgba(16, 19, 34, 0.25);
}
.hv-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-secondary);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 2px 6px;
  margin-bottom: 8px;
}
.hv-tag-accent { color: #1b7a33; background: var(--highlight); border-color: var(--highlight); }
.hv-card p { font-size: 14px; font-weight: 500; margin: 0; }
.hv-card-1 { top: 0; left: 6%; transform: rotate(-3deg); }
.hv-card-2 { top: 16%; left: 42%; transform: rotate(2deg); }
.hv-card-3 { top: 48%; left: 4%; transform: rotate(1deg); }
.hv-card-4 { top: 56%; left: 44%; transform: rotate(-2deg); }

@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; gap: 36px; }
  .hero-visual { min-height: 260px; order: 2; }
  .hero-visual .hv-card { width: 46%; }
}
@media (max-width: 520px) {
  .hero-visual .hv-card { position: static; width: 100%; transform: none !important; margin-bottom: 10px; }
  .hero-visual { min-height: 0; display: flex; flex-direction: column; }
}

/* ===================== SECTION COMMON ===================== */
section { padding: 72px 0; }
section[id] { scroll-margin-top: var(--header-h); }
.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin: 0 0 10px;
}
.section-eyebrow-light { color: var(--highlight); }
section h2 {
  font-size: clamp(26px, 3vw, 34px);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
  max-width: 22ch;
}
.section-intro {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 62ch;
  margin: 0 0 40px;
}
.section-intro-light { color: var(--dark-text-secondary); }

/* ===================== PROBLEMS ===================== */
.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.problem-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px 24px;
}
.problem-mark {
  display: block;
  width: 10px;
  height: 10px;
  background: var(--accent);
  margin-bottom: 18px;
}
.problem-card h3 { font-size: 18px; font-weight: 600; margin: 0 0 8px; }
.problem-card p { color: var(--text-secondary); font-size: 15px; margin: 0; }

@media (max-width: 820px) {
  .problem-grid { grid-template-columns: 1fr; }
}

/* ===================== DEMO (momento scuro) ===================== */
.demo {
  background: var(--dark-bg);
  color: var(--dark-text);
}
.demo-label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--dark-text-secondary);
  border: 1px solid var(--dark-border);
  border-radius: 3px;
  padding: 4px 9px;
  margin-bottom: 28px;
}

.demo-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}
.demo-tab {
  padding: 9px 16px;
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-sm);
  color: var(--dark-text-secondary);
  font-weight: 500;
  font-size: 14px;
}
.demo-tab.is-active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.demo-tab:not(.is-active):hover { color: var(--dark-text); border-color: var(--dark-text-secondary); }

.demo-caption {
  color: var(--dark-text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
  min-height: 24px;
}

.demo-stage {
  background: var(--dark-surface);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-md);
  padding: 28px;
  min-height: 680px;
}

/* --- Nodes shared between fragments (A) and process map (B) --- */
.demo-scene {
  position: relative;
  min-height: 680px;
}
.demo-connections { position: absolute; inset: 0; width: 100%; height: 100%; }
.demo-connections path {
  fill: none;
  stroke: var(--dark-border);
  stroke-width: 1.5;
  opacity: 0;
  transition: opacity 0.4s ease;
}
.demo-scene[data-mode="process"] .demo-connections path { opacity: 1; }
.demo-connections path.is-back { stroke: var(--highlight); stroke-dasharray: 4 4; }
.demo-connections text {
  fill: var(--dark-text-secondary);
  font-family: var(--font-mono);
  font-size: 11px;
  opacity: 0;
  transition: opacity 0.4s ease;
}
.demo-scene[data-mode="process"] .demo-connections text { opacity: 1; }

.demo-nodes { position: absolute; inset: 0; }
.demo-node {
  position: absolute;
  width: 190px;
  background: var(--dark-bg);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  text-align: left;
  cursor: pointer;
  transition: top 0.7s cubic-bezier(.2,.7,.3,1), left 0.7s cubic-bezier(.2,.7,.3,1), transform 0.7s cubic-bezier(.2,.7,.3,1), border-color 0.2s ease;
}
.demo-node:hover, .demo-node:focus-visible { border-color: var(--accent); }
.demo-node-role {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--dark-text-secondary);
  margin-bottom: 6px;
}
.demo-node-title { font-size: 14px; font-weight: 600; margin: 0 0 4px; color: var(--dark-text); }
.demo-node-note { font-size: 12.5px; color: var(--dark-text-secondary); margin: 0; }
.demo-node.is-selected { border-color: var(--highlight); }

@media (prefers-reduced-motion: reduce) {
  .demo-node { transition: none; }
}

/* On narrow viewports, the scattered/map layout becomes a single readable vertical flow */
@media (max-width: 760px) {
  .demo-stage { padding: 18px; min-height: 0; }
  .demo-scene { position: static; min-height: 0; }
  .demo-connections { display: none; }
  .demo-nodes { position: static; display: flex; flex-direction: column; gap: 10px; }
  .demo-node { position: static !important; width: 100%; top: auto !important; left: auto !important; transform: none !important; transition: border-color 0.2s ease; }
}

/* --- Evidence panel (state C) --- */
.demo-evidence-hint { color: var(--dark-text-secondary); font-size: 14px; margin-bottom: 16px; }
.demo-evidence-select {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}
.demo-evidence-select button {
  padding: 7px 12px;
  border: 1px solid var(--dark-border);
  border-radius: 3px;
  font-size: 13px;
  color: var(--dark-text-secondary);
}
.demo-evidence-select button.is-active {
  border-color: var(--highlight);
  color: var(--dark-text);
}
.demo-evidence-panel {
  background: var(--dark-bg);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-md);
  padding: 24px;
}
.demo-evidence-panel dl {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 10px 18px;
  margin: 0;
}
.demo-evidence-panel dt {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--dark-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.demo-evidence-panel dd {
  margin: 0;
  font-size: 14.5px;
  color: var(--dark-text);
}
.demo-evidence-panel dd.is-question { color: var(--highlight); }
@media (max-width: 600px) {
  .demo-evidence-panel dl { grid-template-columns: 1fr; }
  .demo-evidence-panel dt { margin-top: 10px; }
}

/* --- Alternatives (state D) --- */
.demo-alt-label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--dark-text-secondary);
  border: 1px solid var(--dark-border);
  border-radius: 3px;
  padding: 4px 9px;
  display: inline-block;
  margin-bottom: 20px;
}
.demo-alt-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.demo-alt-card {
  background: var(--dark-bg);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-md);
  padding: 20px;
}
.demo-alt-card h3 { font-size: 15.5px; font-weight: 600; margin: 0 0 12px; color: var(--dark-text); }
.demo-alt-card dl { margin: 0; display: grid; gap: 8px; }
.demo-alt-card dt {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dark-text-secondary);
  text-transform: uppercase;
}
.demo-alt-card dd { margin: 0 0 6px; font-size: 13.5px; color: var(--dark-text-secondary); }
@media (max-width: 700px) {
  .demo-alt-grid { grid-template-columns: 1fr; }
}

.demo-actions { margin-top: 20px; }
.demo-method-line {
  margin-top: 36px;
  font-size: 18px;
  font-weight: 600;
  color: var(--dark-text);
}

/* ===================== PATH ===================== */
.path-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}
.path-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px 24px;
  display: flex;
  flex-direction: column;
}
.path-step {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 10px;
}
.path-card h3 { font-size: 18px; font-weight: 600; margin: 0 0 10px; }
.path-card > p { font-size: 15px; color: var(--text-secondary); margin: 0 0 14px; }
.path-deliverables {
  display: grid;
  gap: 6px;
  margin-bottom: 16px;
}
.path-deliverables li {
  font-size: 13.5px;
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
}
.path-deliverables li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 6px;
  height: 6px;
  background: var(--accent);
}
.path-note {
  margin-top: auto;
  font-size: 13px;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
  padding-top: 12px;
}
.path-closing { font-size: 17px; font-weight: 500; color: var(--text); }

@media (max-width: 900px) {
  .path-grid { grid-template-columns: 1fr; }
}

/* ===================== CONTACT ===================== */
.contact-inner {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  margin-bottom: 64px;
}
.demo-notice {
  margin-top: 24px;
  background: #FDF7E8;
  border: 1px solid #EBD9A0;
  border-radius: var(--radius-md);
  padding: 16px 18px;
  font-size: 13.5px;
  color: #6B5A14;
}
.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px 16px;
}
.field { display: flex; flex-direction: column; gap: 6px; }
.field-wide { grid-column: 1 / -1; }
.field label { font-size: 13.5px; font-weight: 600; }
.optional { font-weight: 400; color: var(--text-secondary); }
.field input, .field textarea {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 11px 13px;
  background: var(--surface);
  color: var(--text);
  resize: vertical;
}
.field input:focus, .field textarea:focus { border-color: var(--accent); }
.form-footer { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.form-status { grid-column: 1 / -1; font-size: 14px; color: var(--text-secondary); margin: 0; }
.form-status.is-error { color: #B3261E; }

@media (max-width: 760px) {
  .contact-inner { grid-template-columns: 1fr; gap: 32px; }
  .contact-form { grid-template-columns: 1fr; }
}

/* ===================== FAQ ===================== */
.faq h2 { margin-bottom: 20px; }
.faq-list { display: grid; gap: 10px; max-width: 760px; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 4px 20px;
  background: var(--surface);
}
.faq-item summary {
  cursor: pointer;
  padding: 16px 0;
  font-weight: 600;
  font-size: 15.5px;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--accent);
  flex-shrink: 0;
}
.faq-item[open] summary::after { content: "–"; }
.faq-item p { padding: 0 0 18px; color: var(--text-secondary); font-size: 14.5px; }

/* ===================== FOOTER ===================== */
.site-footer {
  background: var(--dark-bg);
  color: var(--dark-text);
  padding: 40px 0;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 32px;
}
.footer-tag { font-size: 13.5px; color: var(--dark-text-secondary); margin-right: auto; }
.footer-nav { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-nav a { font-size: 14px; color: var(--dark-text-secondary); text-decoration: none; }
.footer-nav a:hover { color: var(--dark-text); }

@media (max-width: 700px) {
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-tag { margin-right: 0; }
}