/* Design Tokens */
:root {
  --color-bg: #ffffff;
  --color-text: #222222;
  --color-text-secondary: #575760;
  --color-link: #1e73be;
  --color-link-hover: #135a96;
  --font-family: 'Roboto', sans-serif;
  --font-size-base: 18px;
  --line-height: 1.8;
  --content-max-width: 800px;
}

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Base */
html {
  font-size: var(--font-size-base);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-weight: 400;
  line-height: var(--line-height);
  color: var(--color-text);
  background: var(--color-bg);
  margin: 0 5%;
}

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

a:hover {
  color: var(--color-link-hover);
  text-decoration: underline;
}

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

/* Layout */
.site-container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 40px 0;
}

/* Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 30px 0;
  border-bottom: 1px solid #e0e0e0;
  margin-bottom: 40px;
}

.site-logo img {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: block;
}

/* Navigation */
.site-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.site-nav a {
  color: var(--color-text);
  font-size: 15px;
  padding: 6px 14px;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}

.site-nav a:hover {
  background: #f0f0f0;
  text-decoration: none;
}

.site-nav a.current {
  background: var(--color-link);
  color: #fff;
}

.site-nav a.current:hover {
  background: var(--color-link-hover);
}

.site-nav a.disabled {
  color: #b2b2be;
  pointer-events: none;
}

/* Main Content */
main {
  padding-bottom: 60px;
}

main h1 {
  font-size: 70px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 8px;
}

main h2 {
  font-size: 30px;
  font-weight: 700;
  line-height: 1.3;
  margin-top: 40px;
  margin-bottom: 16px;
}

main h3 {
  font-size: 22px;
  font-weight: 700;
  margin-top: 30px;
  margin-bottom: 12px;
}

.subtitle {
  font-size: 28px;
  font-weight: 300;
  color: var(--color-text-secondary);
  margin-bottom: 30px;
}

main p {
  margin-bottom: 20px;
}

main ul, main ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

main li {
  margin-bottom: 8px;
}

/* Social Links */
.social-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  list-style: none;
  padding: 0;
  margin-top: 30px;
}

.social-links a {
  display: block;
  color: var(--color-text);
  transition: transform 0.15s ease;
}

.social-links a:hover {
  transform: scale(1.2);
  text-decoration: none;
  color: var(--color-link);
}

.social-links svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
  display: block;
}

/* Project sections */
.project {
  margin-bottom: 40px;
}

.project h2 {
  margin-top: 0;
  margin-bottom: 4px;
}

.project .date {
  font-weight: 700;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}

/* Updated note */
.updated {
  color: var(--color-text-secondary);
  font-size: 15px;
  font-style: italic;
  margin-top: 40px;
}

/* Footer */
.site-footer {
  border-top: 1px solid #e0e0e0;
  padding: 30px 0;
  color: var(--color-text-secondary);
  font-size: 15px;
}

/* Responsive */
@media (max-width: 768px) {
  body {
    margin: 0 20px;
  }

  .site-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding: 20px 0;
  }

  .site-nav {
    gap: 6px;
  }

  .site-nav a {
    font-size: 14px;
    padding: 5px 10px;
  }

  main h1 {
    font-size: 40px;
  }

  .subtitle {
    font-size: 20px;
  }

  main h2 {
    font-size: 24px;
  }

}