/* ===============================
   Reset & Variables
   =============================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Palette: bright editorial tone */
  --bg-primary: #ffffff;
  --bg-secondary: #fafafa;
  --bg-tertiary: #f3f3f3;

  --text-primary: #111111;
  --text-secondary: #555555;
  --text-muted: #8a8a8a;

  --accent: #C8896B;      /* terracotta */
  --accent-2: #B7A28B;    /* champagne/khaki */
  --border: #e9e9e9;
  --shadow: rgba(0, 0, 0, 0.08);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-mono: "SF Mono", Monaco, "Cascadia Code", "Courier New", monospace;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;

  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.85;
  font-size: 16px;
  overflow-x: hidden;
}

/* ===============================
   Typography
   =============================== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 300;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

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

strong { font-weight: 600; }

/* ===============================
   Layout
   =============================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: 96px 0; /* 넉넉한 세로 여백 */
  position: relative;
}

.section-title {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: var(--spacing-lg);
  text-align: center;
  letter-spacing: -0.03em;
  font-weight: 300;
  color: var(--text-primary);
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 72px;
  height: 1px;
  background: var(--accent);
  margin: var(--spacing-md) auto 0;
}

/* ===============================
   Header
   =============================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: var(--spacing-sm) 0;
  transition: var(--transition);
}

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

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.logo span { color: var(--accent); }

.nav {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

.nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
  letter-spacing: 0.02em;
}

.nav a:hover { color: var(--accent); }

.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 1px;
  background: var(--accent);
  transition: var(--transition);
}

.nav a:hover::after { width: 100%; }

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.menu-toggle span {
  display: block;
  width: 25px; height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
}

/* ===============================
   Hero Section
   =============================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: calc(var(--spacing-xl) + 60px) var(--spacing-md) var(--spacing-xl);
  background: linear-gradient(to bottom, rgba(200, 137, 107, 0.06), transparent 60%);
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.hero-content {
  flex: 1;
  min-width: 300px;
  max-width: 600px;
}

.hero-title { margin-bottom: var(--spacing-md); }

.subtitle {
  display: block;
  font-size: clamp(0.85rem, 2vw, 1rem);
  font-weight: 500;
  color: var(--accent);
  margin-bottom: var(--spacing-sm);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.main-title {
  display: block;
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 300;
  line-height: 1.2;
  letter-spacing: -0.04em;
  color: var(--text-primary);
}

.main-title em {
  color: var(--accent);
  font-style: normal;
  font-weight: 500;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.9;
  font-weight: 300;
}

.hero-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.9rem 2.2rem;
  border-radius: 2px;
  font-weight: 500;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  text-align: center;
  letter-spacing: 0.03em;
}

.btn.primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.btn.primary:hover {
  background: #c17660;
  border-color: #c17660;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(200, 137, 107, 0.25);
}

.btn.secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border);
}

.btn.secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.hero-visual {
  flex: 1;
  min-width: 300px;
  max-width: 500px;
}

.code-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: var(--spacing-md);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.9;
  box-shadow: 0 10px 40px var(--shadow);
}

.code-line { color: var(--text-secondary); }
.keyword { color: #c17660; }
.string { color: #6b8e6b; }
.number { color: #d19a66; }

/* ===============================
   About Section
   =============================== */
.about { background: var(--bg-primary); }

.about-content {
  max-width: 800px;
  margin: 0 auto var(--spacing-lg);
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 2;
  font-weight: 300;
}

.about-content p { margin-bottom: var(--spacing-md); }

.about-highlights {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
  max-width: 900px;
  margin: 0 auto;
}

.about-highlights li {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: var(--spacing-md);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  transition: var(--transition);
}

.about-highlights li:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 6px 20px var(--shadow);
}

.about-highlights .icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-xs);
}

.about-highlights strong {
  font-size: 1rem;
  color: var(--text-primary);
  font-weight: 600;
}

.about-highlights span:last-child {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 300;
}

/* ===============================
   Stats Section
   =============================== */
.stats {
  background: var(--bg-secondary);
  position: relative;
}

.stats::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: var(--border);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-lg);
  max-width: 1000px;
  margin: 0 auto;
}

.stat-item {
  text-align: center;
  padding: var(--spacing-md);
  transition: var(--transition);
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-primary);
}

.stat-item:hover { transform: scale(1.03); }

.stat-number {
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 300;
  color: var(--accent);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
  font-family: var(--font-serif);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 400;
  letter-spacing: 0.05em;
}

/* ===============================
   Timeline Section
   =============================== */
.timeline { background: var(--bg-primary); }

.timeline-list {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
}

.timeline-list::before {
  content: '';
  position: absolute;
  left: 28px;
  top: 0; bottom: 0;
  width: 1px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  padding-left: 80px;
  margin-bottom: var(--spacing-lg);
}

.timeline-marker {
  position: absolute;
  left: 20px;
  top: 8px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg-primary);
  z-index: 1;
  box-shadow: 0 0 0 4px var(--bg-secondary);
}

.timeline-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: var(--spacing-md) var(--spacing-lg);
  transition: var(--transition);
}

.timeline-content:hover {
  border-color: var(--accent);
  transform: translateX(10px);
  box-shadow: 0 6px 25px var(--shadow);
}

.timeline-content time {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.timeline-content h3 {
  font-size: 1.35rem;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
  font-weight: 500;
  letter-spacing: -0.02em;
}

.timeline-content p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.8;
  font-weight: 300;
}

.timeline-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.timeline-tags span {
  display: inline-block;
  padding: 0.4rem 1rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 400;
  transition: var(--transition);
}

.timeline-tags span:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ===============================
   Skills Section
   =============================== */
.skills { background: var(--bg-secondary); }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
  max-width: 1000px;
  margin: 0 auto;
}

.skill-category {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: var(--spacing-md) var(--spacing-lg);
  transition: var(--transition);
}

.skill-category:hover {
  border-color: var(--accent);
  box-shadow: 0 6px 20px var(--shadow);
}

.skill-category h3 {
  font-size: 1.15rem;
  margin-bottom: var(--spacing-md);
  color: var(--accent);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.skill-tags span {
  display: inline-block;
  padding: 0.5rem 1.1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 400;
  transition: var(--transition);
}

.skill-tags span:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateY(-2px);
}

/* ===============================
   Contact Section
   =============================== */
.contact { background: var(--bg-primary); }

.contact-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-lg);
  max-width: 1000px;
  margin: 0 auto;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.form-group input,
.form-group textarea {
  padding: 1rem 1.2rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--bg-primary);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.contact-info h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
  font-weight: 400;
  letter-spacing: -0.02em;
}

.social-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.social-links a {
  display: inline-block;
  padding: 0.9rem 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-secondary);
  font-weight: 500;
  transition: var(--transition);
  font-size: 0.9rem;
}

.social-links a:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateX(6px);
}

/* ===============================
   Footer
   =============================== */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: var(--spacing-md) 0;
  text-align: center;
}

.footer p {
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 300;
  letter-spacing: 0.03em;
}

/* ===============================
   Responsive
   =============================== */
@media (max-width: 768px) {
  .nav {
    position: fixed;
    top: 60px; left: 0; right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
    gap: var(--spacing-sm);
  }

  .nav.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .menu-toggle { display: flex; }

  .hero {
    flex-direction: column;
    text-align: center;
    padding-top: calc(var(--spacing-lg) + 60px);
  }

  .hero-actions { justify-content: center; }

  .contact-content { grid-template-columns: 1fr; }

  .timeline-list::before { left: 20px; }
  .timeline-item { padding-left: 60px; }
  .timeline-marker { left: 12px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-actions { flex-direction: column; width: 100%; }
  .btn { width: 100%; }
}