:root {
  --black: #0a0a0a;
  --white: #ffffff;
  --gray: #6b6b6b;
  --line: #dcdcdc;
  --max-width: 720px;
  --space: clamp(1.5rem, 4vw, 3rem);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html {
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  background: var(--white);
  color: var(--black);
  font-family: var(--font-sans);
  line-height: 1.6;
}

a {
  color: inherit;
}

h1, h2, h3 {
  margin: 0;
  font-weight: 700;
  letter-spacing: -0.02em;
}

p {
  margin: 0;
}

.section,
.footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: var(--space);
  padding-right: var(--space);
}

/* Hero */

.hero {
  background: var(--black);
  color: var(--white);
  --gray: #a3a3a3;
  --line: #2e2e2e;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: var(--space);
  padding-right: var(--space);
  padding-top: clamp(4rem, 12vh, 7rem);
  padding-bottom: clamp(3rem, 8vh, 5rem);
}

.subtitle {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--gray);
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(2.75rem, 7vw, 4rem);
  line-height: 1.05;
  max-width: 14ch;
  margin-bottom: 0.5rem;
}

.tagline {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-weight: 500;
  color: var(--gray);
  margin-bottom: 0.75rem;
}

.lede {
  margin-top: 1.25rem;
  max-width: 46ch;
  color: var(--gray);
  font-size: 1.05rem;
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

/* Buttons */

.btn {
  display: inline-block;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.7rem 1.3rem;
  border: 1px solid var(--black);
  border-radius: 999px;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.btn:hover {
  background: var(--black);
  color: var(--white);
}

.btn-primary {
  background: var(--black);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--white);
  color: var(--black);
}

/* Buttons on dark (black) sections: invert the scheme */

.hero .btn {
  border-color: var(--white);
  color: var(--white);
}

.hero .btn:hover {
  background: var(--white);
  color: var(--black);
}

.hero .btn-primary {
  background: var(--white);
  color: var(--black);
}

.hero .btn-primary:hover {
  background: transparent;
  color: var(--white);
}

/* Simple page header (e.g. Impressum) */

.page-header {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem var(--space);
}

.back-link {
  font-family: var(--font-mono);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--gray);
}

.back-link:hover {
  color: var(--black);
}

/* Sections */

.section {
  padding-top: var(--space);
  padding-bottom: var(--space);
  border-top: 1px solid var(--line);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.section.is-visible {
  opacity: 1;
  transform: none;
}

.section h2 {
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.section p {
  color: var(--gray);
  max-width: 60ch;
}

.section h3 {
  font-size: 1rem;
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}

.section h3:first-of-type {
  margin-top: 0;
}

.section a {
  text-decoration-color: var(--line);
  text-underline-offset: 2px;
}

.section a:hover {
  text-decoration-color: var(--black);
}

/* Projects */

.project {
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
}

.project:first-of-type {
  border-top: none;
  padding-top: 0;
}

.project-head {
  margin-bottom: 0.5rem;
}

.project-head h3 {
  font-size: 1.1rem;
}

.project-link {
  display: inline-block;
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none;
  color: var(--black);
}

.project-link:hover {
  text-decoration: underline;
}

/* Contact */

.section-contact {
  max-width: none;
  padding-left: 0;
  padding-right: 0;
  border-top: 1px solid var(--line);
}

.contact-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: var(--space);
  padding-right: var(--space);
}

.contact-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* Footer */

.footer {
  padding-top: 2rem;
  padding-bottom: 3rem;
  color: var(--gray);
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

@media (prefers-reduced-motion: reduce) {
  .section {
    opacity: 1;
    transform: none;
    transition: none;
  }
}