:root {
  --bg:      #fafaf8;
  --surface: #ffffff;
  --border:  #e4e2dc;
  --border2: #d0cdc5;
  --text:    #1a1916;
  --muted:   #8a877f;
  --accent:  #3d6b52;
  --accent2: #6b8f71;
  --danger:  #a0473a;
  --shadow:  rgba(0,0,0,0.06);
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-mono:    'DM Mono', monospace;
  --font-sans-jp: 'Noto Sans JP', sans-serif;
  --font-sans-kr: 'Noto Sans KR', sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans-kr);
  font-weight: 300;
  line-height: 1.7;
  overflow-x: hidden;
}

body.lang-ja { font-family: var(--font-sans-jp); }
body.lang-en { font-family: var(--font-mono); }

/* ── NAV ── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 1.25rem 2.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(250,250,248,0.93);
  backdrop-filter: blur(12px);
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-decoration: none;
}

.nav-right {
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.nav-links {
  display: flex;
  gap: 1.8rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--muted);
  text-decoration: none;
  letter-spacing: 0.06em;
  transition: color 0.2s;
}

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

.lang-switcher {
  display: flex;
  border: 1.5px solid var(--accent);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 1px 6px rgba(61,107,82,0.12);
}

.lang-btn {
  background: none;
  border: none;
  padding: 0.35rem 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  cursor: pointer;
  letter-spacing: 0.06em;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
}

.lang-btn + .lang-btn {
  border-left: 1px solid var(--accent);
}

.lang-btn:hover {
  background: rgba(61,107,82,0.08);
}

.lang-btn.active {
  background: var(--accent);
  color: #fff;
}

/* ── SECTIONS SHARED ── */
section {
  padding: 7rem 2.5rem;
  max-width: 900px;
  margin: 0 auto;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 3rem;
}

.section-label::before {
  content: '//';
  margin-right: 0.5em;
  color: var(--accent);
}

/* ── HERO ── */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-top: 6rem;
  border-bottom: 1px solid var(--border);
}

.hero-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.2rem;
}

.hero-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent2);
  letter-spacing: 0.12em;
  margin-bottom: 1.5rem;
}

.hero-name {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 6rem);
  line-height: 1.05;
  margin-bottom: 1.2rem;
  color: var(--text);
}

.hero-name em {
  font-style: italic;
  color: var(--accent);
}

.hero-desc {
  font-size: 1rem;
  color: var(--muted);
  max-width: 480px;
  line-height: 1.8;
  margin-bottom: 2.5rem;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid var(--border2);
  padding: 0.65rem 1.2rem;
  border-radius: 4px;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  letter-spacing: 0.06em;
}

.hero-cta:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.hero-scroll {
  margin-top: 4rem;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--border2);
  letter-spacing: 0.1em;
  animation: fadeup 2s ease infinite alternate;
}

@keyframes fadeup {
  from { opacity: 0.3; transform: translateY(4px); }
  to   { opacity: 1;   transform: translateY(0); }
}

/* ── ABOUT ── */
#about { border-bottom: 1px solid var(--border); }

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.about-text {
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.9;
}

.about-text strong {
  color: var(--text);
  font-weight: 500;
}

.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-content: flex-start;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--muted);
  letter-spacing: 0.04em;
  background: var(--surface);
}

.tag.accent { border-color: var(--accent); color: var(--accent); }
.tag.green  { border-color: var(--accent2); color: var(--accent2); }

/* ── SKILL ── */
#skill { border-bottom: 1px solid var(--border); }

.skill-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2.5rem;
}

.skill-col-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
  text-transform: uppercase;
}

.skill-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.skill-list li {
  font-size: 0.88rem;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.skill-list li::before {
  content: '•';
  color: var(--accent);
  font-size: 1rem;
  line-height: 1;
}

/* ── EDUCATION ── */
#education { border-bottom: 1px solid var(--border); }

.edu-list {
  display: flex;
  flex-direction: column;
  gap: 1.8rem;
}

.edu-header {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  flex-wrap: wrap;
  margin-bottom: 0.4rem;
}

.edu-name {
  font-size: 0.95rem;
  color: var(--text);
  font-weight: 500;
}

.edu-period {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--muted);
}

.edu-details {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-top: 0.4rem;
}

.edu-details li {
  font-size: 0.85rem;
  color: var(--muted);
  padding-left: 1rem;
  position: relative;
}

.edu-details li::before {
  content: '○';
  position: absolute;
  left: 0;
  font-size: 0.6rem;
  top: 0.25rem;
  color: var(--border2);
}

.edu-details li strong {
  color: var(--text);
  font-weight: 500;
}

/* ── CERTIFICATION ── */
#certification { border-bottom: 1px solid var(--border); }

.cert-list {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.cert-item {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  font-size: 0.88rem;
}

.cert-item::before {
  content: '•';
  color: var(--accent);
  font-size: 1rem;
  line-height: 1;
}

.cert-name { color: var(--text); font-weight: 400; }

.cert-date {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--muted);
}

.cert-note {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--border2);
}

/* ── PROJECTS ── */
#projects { border-bottom: 1px solid var(--border); }

.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.project-card {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  box-shadow: 0 2px 12px var(--shadow);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
}

.project-card:hover {
  box-shadow: 0 6px 24px rgba(0,0,0,0.10);
  transform: translateY(-2px);
}

.project-preview {
  width: 100%;
  height: 220px;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: relative;
}

.project-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  display: block;
  transition: transform 0.4s ease;
}

.project-card:hover .project-preview img {
  transform: scale(1.03);
}

.preview-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--border2);
  letter-spacing: 0.08em;
  background: repeating-linear-gradient(
    45deg,
    var(--bg),
    var(--bg) 8px,
    var(--border) 8px,
    var(--border) 9px
  );
}

.panel-profile-pic {
  width: 170px;
  height: 225px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.project-body {
  padding: 1.6rem 1.8rem 1.5rem;
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.5rem;
}

.project-name {
  font-family: var(--font-display);
  font-size: 1.45rem;
  color: var(--text);
}

.project-link {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--border);
  padding: 0.22rem 0.55rem;
  border-radius: 3px;
  transition: color 0.2s, border-color 0.2s;
  white-space: nowrap;
}

.project-link:hover { color: var(--accent); border-color: var(--accent); }

.project-url {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--accent2);
  margin-bottom: 0.8rem;
}

.project-desc {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: 1.2rem;
}

.project-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.stack-tag {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  padding: 0.2rem 0.5rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--muted);
}

.project-actions {
  margin-top: 1.2rem;
  display: flex;
  gap: 0.6rem;
}

.project-btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid var(--accent);
  padding: 0.4rem 0.9rem;
  border-radius: 3px;
  letter-spacing: 0.05em;
  transition: background 0.2s, color 0.2s;
}

.project-btn:hover {
  background: var(--accent);
  color: #fff;
}

.project-btn-disabled {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 0.4rem 0.9rem;
  border-radius: 3px;
  letter-spacing: 0.05em;
}

/* ── FOOTER ── */
footer {
  text-align: center;
  padding: 3rem 2.5rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--border2);
  letter-spacing: 0.08em;
  border-top: 1px solid var(--border);
}

/* ── FADE IN ── */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
  nav { padding: 1rem 1.2rem; }
  .nav-links { display: none; }
  section { padding: 5rem 1.2rem; }
  .about-grid { grid-template-columns: 1fr; }
  .hero-name { font-size: clamp(2.4rem, 12vw, 4rem); }
  .skill-grid { grid-template-columns: 1fr; gap: 1.8rem; }
  .project-preview { height: 160px; }
  .project-body { padding: 1.2rem 1.2rem 1.1rem; }
}