@import url('https://fonts.googleapis.com/css2?family=Geist:wght@400;600;700&family=JetBrains+Mono:wght@500&display=swap');

:root {
  /* Colors */
  --primary: #000000;
  --secondary: #333333;
  --surface: #ffffff;
  --accent-light: #f5f5f5;
  --accent-border: #e5e5e5;
  
  /* Spacing */
  --unit: 4px;
  --gutter: 24px;
  --margin-mobile: 20px;
  --margin-desktop: 64px;
  --section-gap: 128px;
  
  /* Fonts */
  --font-body: 'Geist', sans-serif;
  --font-label: 'JetBrains Mono', monospace;
}

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

body {
  font-family: var(--font-body);
  background-color: var(--surface);
  color: var(--primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography Scale */
h1, .display-lg {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
}

@media (min-width: 768px) {
  h1, .display-lg {
    font-size: 72px;
    letter-spacing: -0.04em;
  }
}

h2, .headline-md {
  font-size: 32px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.body-lg {
  font-size: 18px;
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: -0.01em;
}

.label-technical {
  font-family: var(--font-label);
  font-size: 12px;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Layout */
.container {
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding-left: var(--margin-mobile);
  padding-right: var(--margin-mobile);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--margin-desktop);
    padding-right: var(--margin-desktop);
  }
}

.grid-12 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gutter);
}

@media (min-width: 1024px) {
  .grid-12 {
    grid-template-columns: repeat(12, 1fr);
  }
}

.section {
  padding-top: var(--section-gap);
  padding-bottom: var(--section-gap);
  border-bottom: 1px solid var(--accent-border);
}

/* Background grid effect */
.bg-grid {
  background-size: 40px 40px;
  background-image: 
    linear-gradient(to right, var(--accent-border) 1px, transparent 1px), 
    linear-gradient(to bottom, var(--accent-border) 1px, transparent 1px);
}

/* Components */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background-color: var(--primary);
  color: var(--surface);
  font-family: var(--font-label);
  font-weight: bold;
  padding: 12px 24px;
  border: 1px solid var(--primary);
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  border-radius: 0;
}

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

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--surface);
  color: var(--primary);
  font-family: var(--font-label);
  padding: 12px 24px;
  border: 1px solid var(--primary);
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  border-radius: 0;
}

.btn-secondary:hover {
  background-color: var(--primary);
  color: var(--surface);
}

/* Header */
header {
  border-bottom: 1px solid var(--accent-border);
  padding-top: var(--gutter);
  padding-bottom: var(--gutter);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--surface);
  position: sticky;
  top: 0;
  z-index: 50;
}

header a.logo {
  text-decoration: none;
  color: var(--primary);
}

nav {
  display: none;
}

@media (min-width: 768px) {
  nav {
    display: flex;
    gap: 32px;
  }
}

nav a {
  text-decoration: none;
  color: var(--secondary);
  transition: color 0.2s ease;
}

nav a:hover {
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
}

/* Hero Section */
.hero-content {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

@media (min-width: 1024px) {
  .hero-text {
    grid-column: span 6;
  }
  .hero-visual {
    grid-column: span 6;
  }
}

.hero-description {
  max-width: 600px;
  border-left: 4px solid var(--primary);
  padding-left: 16px;
}

.hero-visual {
  border: 1px solid var(--primary);
  min-height: 400px;
  position: relative;
  background-color: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-visual img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(100%);
}

/* Section Title block */
.section-title-col {
  position: relative;
}

@media (min-width: 1024px) {
  .section-title-col {
    grid-column: span 4;
  }
  .section-content-col {
    grid-column: span 8;
  }
  .section-title-sticky {
    position: sticky;
    top: 96px;
  }
}

.section-indicator {
  width: 48px;
  height: 4px;
  background-color: var(--primary);
  margin-top: 16px;
  margin-bottom: 24px;
}

/* About Section */
.about-card {
  background-color: var(--surface);
  border: 1px solid var(--accent-border);
  padding: 32px;
}

/* Project Cards */
.project-card {
  border: 1px solid var(--primary);
  background-color: var(--surface);
  margin-bottom: 32px;
}

.project-card:last-child {
  margin-bottom: 0;
}

.project-header {
  border-bottom: 1px solid var(--primary);
  padding: 16px;
  background-color: var(--primary);
  color: var(--surface);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.project-body {
  padding: 32px;
}

.project-body p {
  margin-bottom: 24px;
}

.project-contributions {
  border-top: 1px solid var(--accent-border);
  padding-top: 16px;
  margin-top: 24px;
}

.project-contributions span {
  display: block;
  color: var(--secondary);
  margin-bottom: 8px;
}

.project-contributions ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.project-contributions li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.project-contributions li::before {
  content: '>';
  color: var(--primary);
}

/* Footer */
footer {
  border-top: 1px solid var(--primary);
  padding-top: var(--gutter);
  padding-bottom: var(--gutter);
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

@media (min-width: 768px) {
  footer {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-info {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 400px;
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

@media (min-width: 768px) {
  .footer-contact {
    align-items: flex-end;
  }
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

@media (min-width: 768px) {
  .footer-links {
    align-items: flex-end;
  }
}

.footer-links a {
  color: var(--secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--primary);
}

.flex-center {
  display: flex;
  align-items: center;
}

.gap-1 { gap: 4px; }
.text-xs { font-size: 10px; }
.text-sm { font-size: 14px; }