@font-face {
  font-family: 'JetBrains Mono';
  src: url('/fonts/jetbrains-mono-5.2.5.woff2') format('woff2');
  font-weight: 100 800;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --text-primary: #c9d1d9;
  --text-secondary: #8b949e;
  --text-accent: #58a6ff;
  --border-color: #30363d;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;
  --transition-fast: 0.2s ease;
  --shadow-sm: 0 1px 0 rgba(27, 31, 35, 0.04);
}

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

html {
  -webkit-text-size-adjust: 100%;
  font-size: 100%;
  color-scheme: dark;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: 18px;
  line-height: 1.6;
  font-weight: 400;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* layout */
.container {
  position: relative;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

@media (min-width: 400px) {
  .container {
    width: 85%;
    padding: 0;
  }
}

@media (min-width: 550px) {
  .container {
    width: 80%;
  }
}

main {
  flex: 1;
  padding: var(--spacing-xl) 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* typography */
h1, h2 {
  color: var(--text-primary);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

h1 {
  margin-top: 0;
  font-weight: 800;
  font-size: 24px;
  line-height: 1.2;
}

@media (min-width: 550px) {
  h1 {
    font-size: 48px;
  }
}

p {
  margin-top: 0;
  color: var(--text-secondary);
}

/* links */
a {
  color: var(--text-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  text-decoration: underline;
}

/* nav */
.nav-header {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

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

.nav-brand-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 4px;
}

.nav-link:hover,
.nav-link.active {
  color: var(--text-primary);
  background-color: var(--bg-tertiary);
  text-decoration: none;
}

/* hero */
.hero {
  text-align: center;
}

.hero-avatar {
  display: block;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  border: 4px solid var(--border-color);
  margin: 0 auto 2rem auto;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}

/* buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: 6px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color var(--transition-fast),
              transform var(--transition-fast),
              border-color var(--transition-fast);
  border: 1px solid transparent;
  text-decoration: none;
  gap: var(--spacing-sm);
  font-size: 1rem;
}

.btn:hover {
  text-decoration: none;
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--text-secondary);
  transform: translateY(-1px);
}

.btn-icon svg {
  width: 20px;
  height: 20px;
}

/* footer */
footer {
  text-align: center;
  padding: var(--spacing-lg) 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-top: 1px solid var(--border-color);
  margin-top: auto;
}

/* privacy */
.privacy-content {
  max-width: 700px;
  margin: 0 auto;
  text-align: left;
}

.privacy-content h2 {
  margin-top: var(--spacing-xl);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: var(--spacing-sm);
}

/* focus */
a:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--text-accent);
  outline-offset: 2px;
}

/* narrow screens */
@media (max-width: 550px) {
  .btn {
    width: 100%;
    margin-bottom: var(--spacing-sm);
  }

  .nav-links {
    gap: var(--spacing-xs);
  }

  .nav-link {
    font-size: 0.9rem;
    padding: var(--spacing-xs);
  }

  /* icon-only brand; text stays for screen readers */
  .nav-brand-text {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
    border: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none !important;
  }
}