:root {
  color-scheme: dark;
  --bg: #08111f;
  --bg-soft: #0d1829;
  --panel: #101d31;
  --panel-strong: #14243b;
  --line: rgba(148, 163, 184, 0.2);
  --line-strong: rgba(56, 189, 248, 0.35);
  --text: #e5edf7;
  --muted: #a8b5c7;
  --subtle: #75859b;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --accent-soft: rgba(56, 189, 248, 0.12);
  --max-width: 1120px;
  --radius: 8px;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.34);
  font-family:
    Pretendard,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 20% 0%, rgba(14, 165, 233, 0.16), transparent 34rem),
    linear-gradient(180deg, #07101d 0%, var(--bg) 45%, #060c16 100%);
  line-height: 1.65;
  word-break: keep-all;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(var(--max-width), calc(100% - 40px));
  min-height: 72px;
  margin: 0 auto;
  backdrop-filter: blur(18px);
}

.brand,
.nav-links {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  display: inline-grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--accent);
  background: rgba(56, 189, 248, 0.08);
  font-size: 0.84rem;
}

.nav-links {
  gap: 22px;
  color: var(--muted);
  font-size: 0.94rem;
}

.nav-links a {
  transition:
    color 180ms ease,
    transform 180ms ease;
}

.nav-links a:hover {
  color: var(--accent);
  transform: translateY(-1px);
}

.section {
  width: min(var(--max-width), calc(100% - 40px));
  margin: 0 auto;
  padding: 92px 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(360px, 0.92fr);
  gap: 52px;
  align-items: center;
  min-height: calc(100vh - 72px);
  padding-top: 46px;
}

.eyebrow,
.section-kicker,
.project-tag {
  margin: 0;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 780px;
  margin: 18px 0 20px;
  font-size: clamp(3.3rem, 7vw, 5.9rem);
  line-height: 0.98;
  letter-spacing: 0;
}

h2 {
  max-width: 760px;
  margin: 10px 0 0;
  font-size: clamp(2rem, 4vw, 3.1rem);
  line-height: 1.12;
  letter-spacing: 0;
}

h3 {
  margin: 0;
  font-size: 1.16rem;
  line-height: 1.35;
  letter-spacing: 0;
}

.hero-subtitle {
  max-width: 760px;
  margin: 0 0 18px;
  color: #d8e7f5;
  font-size: clamp(1.14rem, 2vw, 1.45rem);
  line-height: 1.55;
}

.hero-copy,
.about-copy p,
.contact-section p,
.card p {
  color: var(--muted);
}

.hero-copy {
  max-width: 720px;
  margin: 0 0 34px;
  font-size: 1.04rem;
}

.hero-actions,
.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 800;
  transition:
    border-color 180ms ease,
    background 180ms ease,
    color 180ms ease,
    transform 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  background: var(--accent);
  color: #04111d;
}

.button-primary:hover {
  background: #7dd3fc;
}

.button-secondary {
  border-color: var(--line);
  background: rgba(15, 23, 42, 0.65);
  color: var(--text);
}

.button-secondary:hover {
  border-color: var(--line-strong);
  color: var(--accent);
}

.system-visual {
  position: relative;
  min-height: 520px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(rgba(148, 163, 184, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.08) 1px, transparent 1px),
    linear-gradient(145deg, rgba(16, 29, 49, 0.92), rgba(8, 17, 31, 0.96));
  background-size:
    32px 32px,
    32px 32px,
    auto;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.system-visual::before,
.system-visual::after {
  position: absolute;
  inset: 74px 52px auto;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.55), transparent);
  content: "";
}

.system-visual::after {
  inset: auto 52px 122px;
}

.visual-topline,
.status-dot,
.node {
  display: flex;
  align-items: center;
}

.visual-topline {
  justify-content: space-between;
  margin-bottom: 38px;
  color: var(--subtle);
  font-size: 0.86rem;
  font-weight: 700;
}

.status-dot {
  gap: 8px;
  color: #86efac;
}

.status-dot::before {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #22c55e;
  box-shadow: 0 0 18px rgba(34, 197, 94, 0.8);
  content: "";
}

.node {
  position: relative;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  min-height: 118px;
  padding: 20px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: var(--radius);
  background: rgba(8, 17, 31, 0.82);
}

.node-core {
  min-height: 150px;
  margin-bottom: 24px;
  border-color: var(--line-strong);
  background: linear-gradient(145deg, rgba(56, 189, 248, 0.17), rgba(15, 23, 42, 0.88));
}

.node-label {
  margin-bottom: 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.node strong {
  font-size: 1.22rem;
}

.visual-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.split-section {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 56px;
  align-items: start;
}

.about-copy {
  display: grid;
  gap: 20px;
}

.about-copy p {
  margin: 0;
  font-size: 1.04rem;
}

.section-heading {
  margin-bottom: 34px;
}

.card-grid {
  display: grid;
  gap: 16px;
}

.strength-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

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

.card {
  min-height: 220px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(16, 29, 49, 0.92), rgba(13, 24, 41, 0.82));
  transition:
    border-color 180ms ease,
    transform 180ms ease,
    background 180ms ease;
}

.card:hover {
  border-color: var(--line-strong);
  background: linear-gradient(180deg, rgba(20, 36, 59, 0.98), rgba(13, 24, 41, 0.88));
  transform: translateY(-4px);
}

.card-index {
  display: block;
  margin-bottom: 46px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 900;
}

.card p {
  margin: 14px 0 0;
}

.project-card {
  min-height: 250px;
}

.project-tag {
  margin-bottom: 28px;
  letter-spacing: 0.04em;
  text-transform: none;
}

.skills-layout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.skill-group {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(16, 29, 49, 0.76);
}

.skill-group:last-child {
  grid-column: 1 / -1;
}

.skill-group h3 {
  margin-bottom: 18px;
}

.pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.pill-list span {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid rgba(56, 189, 248, 0.24);
  border-radius: 999px;
  background: var(--accent-soft);
  color: #d9f3ff;
  font-size: 0.92rem;
  font-weight: 700;
}

.interest-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.interest-list li {
  padding: 18px 20px;
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  background: rgba(16, 29, 49, 0.72);
  color: #d7e4f2;
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 42px;
  align-items: center;
  margin-bottom: 48px;
  padding: 46px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.14), rgba(16, 29, 49, 0.88));
}

.contact-section p {
  max-width: 720px;
  margin: 18px 0 0;
}

.contact-actions {
  justify-content: flex-end;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  width: min(var(--max-width), calc(100% - 40px));
  margin: 0 auto;
  padding: 28px 0 44px;
  border-top: 1px solid var(--line);
  color: var(--subtle);
  font-size: 0.9rem;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 520ms ease,
    transform 520ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media (max-width: 980px) {
  .hero,
  .split-section,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 64px;
  }

  .system-visual {
    min-height: auto;
  }

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

  .contact-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 720px) {
  .site-header {
    align-items: flex-start;
    min-height: auto;
    padding: 18px 0;
  }

  .nav-links {
    display: none;
  }

  .section {
    width: min(100% - 28px, var(--max-width));
    padding: 64px 0;
  }

  .hero {
    gap: 36px;
    padding-top: 46px;
  }

  h1 {
    font-size: clamp(2.72rem, 14vw, 4rem);
  }

  .hero-subtitle {
    font-size: 1.08rem;
  }

  .button,
  .hero-actions,
  .contact-actions {
    width: 100%;
  }

  .system-visual,
  .contact-section {
    padding: 20px;
  }

  .visual-grid,
  .strength-grid,
  .project-grid,
  .skills-layout {
    grid-template-columns: 1fr;
  }

  .skill-group:last-child {
    grid-column: auto;
  }

  .card,
  .project-card {
    min-height: auto;
  }

  .card-index {
    margin-bottom: 28px;
  }

  .site-footer {
    flex-direction: column;
    gap: 8px;
    width: min(100% - 28px, var(--max-width));
  }
}