:root {
  --bg: #f6f3ee;
  --surface: #ffffff;
  --surface-alt: #ebe4da;
  --text: #1f2933;
  --muted: #5f6c7b;
  --accent: #365f91;
  --accent-dark: #24466d;
  --border: #d9d1c7;
  --shadow: 0 16px 40px rgba(31, 41, 51, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

a:hover {
  color: var(--accent-dark);
}

.site-header {
  padding: 24px;
}

.nav {
  max-width: 1120px;
  margin: 0 auto;
  padding: 18px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  color: var(--text);
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.95rem;
}

.hero {
  max-width: 1120px;
  margin: 48px auto 72px;
  padding: 64px;
  background: linear-gradient(135deg, #ffffff 0%, #efe7dc 100%);
  border: 1px solid var(--border);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.15;
}

h1 {
  max-width: 880px;
  font-size: clamp(2.4rem, 6vw, 4.8rem);
  letter-spacing: -0.05em;
}

h2 {
  max-width: 780px;
  font-size: clamp(1.8rem, 4vw, 3rem);
  letter-spacing: -0.035em;
}

h3 {
  font-size: 1.4rem;
}

.hero-text {
  max-width: 720px;
  color: var(--muted);
  font-size: 1.2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.button {
  display: inline-block;
  border: 0;
  border-radius: 999px;
  padding: 12px 20px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.button.primary {
  background: var(--accent);
  color: #ffffff;
}

.button.primary:hover {
  background: var(--accent-dark);
  color: #ffffff;
}

.button.secondary {
  background: #ffffff;
  color: var(--accent);
  border: 1px solid var(--border);
}

.section {
  max-width: 1120px;
  margin: 0 auto;
  padding: 72px 24px;
}

.alt-section {
  max-width: 100%;
  background: var(--surface-alt);
}

.alt-section > * {
  max-width: 1120px;
  margin-left: auto;
  margin-right: auto;
}

.section-heading {
  margin-bottom: 32px;
}

.section-heading p {
  max-width: 720px;
  color: var(--muted);
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.project-card,
.demo-card,
.about-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.project-card {
  padding: 28px;
}

.project-number {
  color: var(--accent);
  font-weight: 800;
  margin-top: 0;
}

.project-card p {
  color: var(--muted);
}

.project-card ul {
  padding-left: 20px;
  color: var(--text);
}

.project-card li {
  margin-bottom: 10px;
}

.portfolio-note {
  margin-top: 32px;
}

.demo-card {
  padding: 28px;
  margin-bottom: 48px;
}

.summary-box {
  margin: 20px 0;
  padding: 16px;
  background: #f7f8fa;
  border: 1px solid var(--border);
  border-radius: 16px;
  color: var(--muted);
}

.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: #ffffff;
}

th,
td {
  padding: 14px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

th {
  color: var(--muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.formula-heading {
  margin-top: 64px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 800;
}

select {
  width: 100%;
  max-width: 360px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 12px;
  font: inherit;
  background: #ffffff;
}

.formula-list {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.formula-item {
  padding: 18px;
  background: #f7f8fa;
  border: 1px solid var(--border);
  border-radius: 16px;
}

.formula-item h3 {
  margin-bottom: 6px;
}

.formula-type {
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.about-card {
  padding: 36px;
}

.about-card p {
  max-width: 780px;
  color: var(--muted);
}

.footer {
  padding: 32px 24px;
  color: var(--muted);
  text-align: center;
}

@media (max-width: 860px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    gap: 16px;
  }

  .nav-links {
    flex-wrap: wrap;
  }

  .hero {
    padding: 36px 24px;
  }

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