:root {
  /* SemPipes wordmark: Sem #F3637C, Pipes #2F3950 */
  --sempipes-sem: #f3637c;
  --sempipes-pipes: #2f3950;

  /* SemPiper wordmark: Sem #94a3b8 (slate-400, demo header), Piper #2F3950 */
  --sempiper-sem: #94a3b8;
  --sempiper-piper: #2f3950;

  /* UI accents */
  --coral: #f3637c;
  --coral-dark: #e04f68;
  --coral-light: #fde8ec;
  --slate: #2f3950;
  --slate-dark: #252d3f;
  --slate-light: #e8ebf0;
  --sempipes-accent: #3b82f6;

  --bg: #fafafa;
  --surface: #ffffff;
  --text: #18181b;
  --muted: #57534e;
  --border: #e4e4e7;
  --shadow: 0 1px 3px rgba(45, 52, 71, 0.08);
  --radius: 12px;
  --max: 1080px;
  --font: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--muted);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a.link-sempiper {
  color: var(--sempiper-sem);
}

a.link-sempiper:hover {
  color: #7b8fa3;
}

a.link-sempipes {
  color: var(--sempipes-sem);
}

a.link-sempipes:hover {
  color: var(--coral-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
}

.nav-brand:hover {
  text-decoration: none;
}

.nav-brand img {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  font-size: 0.9rem;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--sempiper-sem);
}

.nav-links a.link-sempipes {
  color: var(--sempipes-sem);
}

.nav-links a.link-sempipes:hover {
  color: var(--coral-dark);
}

.brand-sempiper .sem {
  color: var(--sempiper-sem);
}

.brand-sempiper .piper {
  color: var(--sempiper-piper);
}

.brand-sempipes .sem {
  color: var(--sempipes-sem);
}

.brand-sempipes .pipes {
  color: var(--sempipes-pipes);
}

/* Hero */
.hero {
  background: linear-gradient(160deg, var(--coral-light) 0%, var(--bg) 55%);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 3.5rem 1.5rem 3rem;
  text-align: center;
}

.hero-logo {
  width: 88px;
  height: 88px;
  margin: 0 auto 1.25rem;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.hero .subtitle {
  max-width: 720px;
  margin: 0 auto 2rem;
  font-size: 1.1rem;
  color: var(--muted);
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 1rem;
  max-width: 720px;
  margin: 0 auto 2rem;
}

.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 0.75rem;
  box-shadow: var(--shadow);
}

.stat-value {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--coral);
  line-height: 1.1;
}

.stat-label {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.8rem;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}

.btn-sempiper {
  background: var(--sempiper-sem);
  color: #fff;
}

.btn-sempiper:hover {
  background: #7b8fa3;
  text-decoration: none;
}

.btn-sempipes {
  background: var(--sempipes-sem);
  color: #fff;
}

.btn-sempipes:hover {
  background: var(--coral-dark);
  text-decoration: none;
}

.btn-outline {
  background: var(--surface);
  color: var(--slate);
  border-color: var(--slate);
}

.btn-outline:hover {
  background: var(--slate-light);
  border-color: var(--slate-dark);
  color: var(--slate-dark);
  text-decoration: none;
}

/* Sections */
.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 3.5rem 1.5rem;
}

.section + .section {
  padding-top: 0;
}

.section-label {
  margin: 0 0 1rem;
  font-size: clamp(1.4rem, 3vw, 1.85rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.section p {
  margin: 0 0 1rem;
  color: var(--muted);
}

.section p:last-child {
  margin-bottom: 0;
}

.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

/* Steps */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.steps-interface {
  grid-template-columns: repeat(3, 1fr);
  margin-top: 2rem;
}

.steps-interface .step-num {
  width: 2rem;
  height: 2rem;
  background: #000;
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
}

.step {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  height: 100%;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  margin-bottom: 0.75rem;
  border-radius: 50%;
  background: var(--coral-light);
  color: var(--coral);
  font-size: 0.85rem;
  font-weight: 700;
}

.steps.sempipes .step-num {
  background: var(--slate-light);
  color: var(--slate);
}

.step h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.step p {
  margin: 0;
  flex: 1;
  font-size: 0.9rem;
}

/* Figure */
.figure {
  margin-top: 2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.figure img {
  width: 100%;
}

.figure figcaption {
  padding: 1rem 1.25rem;
  font-size: 0.88rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  background: #fafaf9;
}

/* Table */
.table-wrap {
  overflow-x: auto;
  margin-top: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

th,
td {
  padding: 0.85rem 1.1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  background: #f5f5f4;
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

tr:last-child td {
  border-bottom: none;
}

code {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.85em;
  background: #f5f5f4;
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

/* Scenario cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.card .tag {
  display: inline-block;
  margin-bottom: 0.75rem;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: var(--coral-light);
  color: var(--coral);
  font-size: 0.75rem;
  font-weight: 600;
}

.card p {
  font-size: 0.92rem;
}

.card ul {
  margin: 0.75rem 0 0;
  padding-left: 1.2rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.card li {
  margin-bottom: 0.3rem;
}

/* Access */
.access-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.access-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.access-card.sempiper {
  border-top: 3px solid var(--coral);
}

.access-card.sempipes {
  border-top: 3px solid var(--slate);
}

.access-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.access-card p {
  font-size: 0.92rem;
}

.code-block {
  position: relative;
  margin-top: 1.5rem;
  background: var(--slate-dark);
  border-radius: var(--radius);
  overflow: hidden;
}

.code-block pre {
  margin: 0;
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.82rem;
  line-height: 1.55;
  color: #e7e5e4;
}

.copy-btn {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid #44403c;
  border-radius: 6px;
  background: #292524;
  color: #d6d3d1;
  font-size: 0.75rem;
  cursor: pointer;
}

.copy-btn:hover {
  background: #44403c;
}

/* Citation */
.cite-heading {
  margin: 2rem 0 0.75rem;
  font-size: 1rem;
  font-weight: 600;
}

.cite-heading:first-of-type {
  margin-top: 1.25rem;
}

.cite-block {
  margin-top: 0;
}

/* Team */
.team {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.team-member {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
}

.team-member h3 {
  margin: 0 0 0.25rem;
  font-size: 1rem;
}

.team-member .affiliation {
  margin: 0 0 0.5rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.team-member a {
  font-size: 0.88rem;
}

/* Footer */
.footer {
  margin-top: 2rem;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.85rem;
  color: var(--muted);
}

.footer a.link-sempiper {
  color: var(--sempiper-sem);
}

.footer a.link-sempipes {
  color: var(--sempipes-sem);
}

@media (max-width: 900px) {
  .steps-interface {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .nav-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-inner {
    padding-top: 2.5rem;
  }

  .steps-interface {
    grid-template-columns: 1fr;
  }
}