/* ─── 홈 페이지 전용 테마 (밝은 포트폴리오 스타일) ─── */
:root {
  --accent:        #1e6fd9;
  --accent-hover:  #1558b0;
  --bg:            #f5f7fa;
  --bg-card:       #ffffff;
  --bg-section-alt:#eef2f7;
  --border:        #d0dce8;
  --text:          #1a2635;
  --text-secondary:#4a6a8a;
  --text-muted:    #8aa0b8;
  --radius:        8px;
  --shadow:        0 2px 12px rgba(0, 0, 0, 0.08);
  --font-sans:     -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width:     860px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.7;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* ─── 상단 네비 ─── */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
  letter-spacing: 0.05em;
}

.nav-link {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ─── Hero ─── */
.hero {
  text-align: center;
  padding: 80px 24px 60px;
  background: linear-gradient(135deg, #eef5ff 0%, #f5f7fa 100%);
}

.hero-name {
  font-size: 48px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.hero-title {
  font-size: 20px;
  color: var(--text-secondary);
}

/* ─── 섹션 공통 ─── */
.section {
  padding: 60px 24px;
}

.section:nth-child(even) {
  background: var(--bg-section-alt);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 28px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}

.empty {
  color: var(--text-muted);
  font-style: italic;
}

/* ─── Bio ─── */
.bio p {
  color: var(--text-secondary);
  max-width: 640px;
}

/* ─── Projects ─── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.card-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.card-desc {
  font-size: 14px;
  color: var(--text-secondary);
  flex: 1;
}

.card-link {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
}

/* ─── Tech Stack ─── */
.skill-group {
  margin-bottom: 20px;
}

.skill-category {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 4px 14px;
  font-size: 13px;
  color: var(--text-secondary);
}

/* ─── Career Timeline ─── */
.timeline {
  list-style: none;
  border-left: 2px solid var(--border);
  padding-left: 24px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.timeline-item {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 16px;
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -31px;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid #fff;
}

.timeline-period {
  font-size: 13px;
  color: var(--text-muted);
  padding-top: 2px;
  white-space: nowrap;
}

.timeline-content strong {
  font-weight: 700;
  color: var(--text);
}

.timeline-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ─── Contact / Footer ─── */
.contact {
  background: var(--text) !important;
  color: #d0e8ff;
}

.contact .section-title {
  color: #fff;
  border-bottom-color: var(--accent);
}

.contact-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.contact-item {
  color: #a0c8f0;
  font-size: 15px;
}

.contact-item:hover { color: #fff; }

.copyright {
  font-size: 13px;
  color: var(--text-muted);
}

/* ─── 반응형 ─── */
@media (max-width: 600px) {
  .hero-name { font-size: 36px; }
  .hero-title { font-size: 16px; }
  .timeline-item { grid-template-columns: 1fr; gap: 4px; }
  .timeline-period { font-size: 12px; }
}