:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --line: #e2e8f0;
  --accent: #2563eb;
  --max-width: 920px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: "Pretendard", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.container {
  width: min(var(--max-width), calc(100% - 2rem));
  margin-inline: auto;
}

.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  padding: 2.25rem 0 1.25rem;
}

h1 {
  margin: 0;
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  line-height: 1.25;
}

#headline {
  color: var(--muted);
  margin: 0.45rem 0 1rem;
}

.top-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.top-nav a {
  text-decoration: none;
  color: var(--accent);
  font-weight: 600;
  border: 1px solid #bfdbfe;
  background: #eff6ff;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  font-size: 0.92rem;
}

.section {
  margin: 1rem 0;
  padding: 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 0.75rem;
}

h2 {
  margin: 0 0 0.8rem;
  font-size: 1.15rem;
}

.stack {
  display: grid;
  gap: 0.8rem;
}

.card,
.item {
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: 0.85rem;
  background: #fcfdff;
}

.item h3,
.card h3 {
  margin: 0;
  font-size: 1.02rem;
}

.meta {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

ul {
  margin: 0.6rem 0 0;
  padding-left: 1rem;
}

.cards {
  display: grid;
  gap: 0.8rem;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: 0.45rem;
}

.tag {
  border-radius: 999px;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--line);
  background: #f8fafc;
  font-size: 0.88rem;
}

.site-footer {
  padding: 0 0 2rem;
  color: var(--muted);
}

@media (min-width: 768px) {
  .section {
    padding: 1.35rem;
  }

  .cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}