/* ===== CSS 변수 ===== */
:root {
  --bg-deep: #0a0a0f;
  --bg-card: rgba(18, 18, 28, 0.72);
  --bg-card-hover: rgba(26, 26, 40, 0.85);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --text: #f4f4f8;
  --text-muted: #9a9ab0;
  --accent: #7c6cf9;
  --accent-2: #00d4aa;
  --gradient: linear-gradient(135deg, #7c6cf9 0%, #00d4aa 100%);
  --radius: 14px;
  --radius-lg: 22px;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
  --header-h: 72px;
  --font: "Outfit", system-ui, sans-serif;
  --transition: 0.25s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg-deep);
  min-height: 100vh;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  color: var(--accent-2);
}

.skip-link {
  position: absolute;
  left: -9999px;
  z-index: 9999;
  padding: 0.75rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.container {
  width: min(1200px, 94vw);
  margin-inline: auto;
}

/* ===== 헤더 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(10, 10, 15, 0.9);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.site-header.is-open {
  background: #050509;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.anchor-top {
  height: 0;
  overflow: hidden;
  pointer-events: none;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  position: relative;
}

.header-datetime {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.85rem;
  min-width: 300px;
  padding: 0.45rem 1.1rem;
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text);
  background: rgba(5, 5, 9, 0.72);
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.35);
  pointer-events: none;
}

.header-datetime__date,
.header-datetime__time {
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.header-datetime__time {
  color: var(--accent-2);
}

.header-datetime__sep {
  flex-shrink: 0;
  width: 1px;
  align-self: stretch;
  min-height: 1.1em;
  margin-block: 0.1em;
  background: rgba(255, 255, 255, 0.22);
  border-radius: 1px;
}

.site-nav {
  padding-inline-end: clamp(0.75rem, 3vw, 1.65rem);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.logo-mark {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gradient);
  box-shadow: 0 0 20px rgba(124, 108, 249, 0.6);
}

.logo-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.site-header.is-open .nav-toggle-bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.site-header.is-open .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header.is-open .nav-toggle-bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

.nav-list {
  display: flex;
  gap: clamp(1.15rem, 2.8vw, 2rem);
  list-style: none;
  margin: 0;
  padding: 0;
}

@media (min-width: 721px) {
  .nav-list {
    margin-inline-start: clamp(0.75rem, 2vw, 1.5rem);
    padding-inline-end: 0.15rem;
  }
}

.nav-list a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: color var(--transition);
}

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

/* ===== 히어로 ===== */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  padding: 4rem 0 5rem;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background:
    radial-gradient(
      ellipse 80% 50% at 50% -20%,
      rgba(124, 108, 249, 0.35),
      transparent
    ),
    radial-gradient(
      ellipse 60% 40% at 100% 50%,
      rgba(0, 212, 170, 0.12),
      transparent
    ),
    radial-gradient(
      ellipse 50% 60% at 0% 80%,
      rgba(124, 108, 249, 0.15),
      transparent
    ),
    var(--bg-deep);
}

.hero-bg__video {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
}

.hero-bg__tint {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(
      180deg,
      rgba(10, 10, 15, 0.45) 0%,
      rgba(10, 10, 15, 0.62) 45%,
      rgba(10, 10, 15, 0.82) 100%
    ),
    radial-gradient(
      ellipse 100% 50% at 50% -10%,
      rgba(124, 108, 249, 0.1),
      transparent 52%
    );
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 640px;
}

.hero-title {
  margin: 0 0 0.85rem;
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-roles {
  margin: 0 0 1.25rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

.hero-lead {
  margin: 0 0 2rem;
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 520px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-start;
  gap: 0.75rem clamp(1rem, 2.5vw, 1.6rem);
  max-width: 100%;
}

.hero-nav-btn {
  flex: 0 1 auto;
}

.hero-nav-btn--primary {
  padding-inline: 1.6rem;
  padding-block: 0.88rem;
  font-size: 0.96rem;
  font-weight: 600;
}

/* 참고 레이아웃처럼: 어두운 히어로 위에 밝은 메인 버튼 */
.hero-actions .hero-nav-btn--primary.btn-primary {
  background: rgba(246, 246, 250, 0.96);
  color: var(--bg-deep);
  border: none;
  box-shadow: 0 4px 26px rgba(0, 0, 0, 0.32);
  transition: transform var(--transition), box-shadow var(--transition),
    background var(--transition);
}

.hero-actions .hero-nav-btn--primary.btn-primary:hover {
  background: #ffffff;
  color: var(--bg-deep);
  box-shadow: 0 10px 36px rgba(0, 0, 0, 0.42),
    0 0 0 1px rgba(255, 255, 255, 0.35);
  transform: translateY(-2px);
}

.hero-actions .hero-nav-btn--primary.btn-primary:active {
  transform: translateY(0) scale(0.98);
}

.hero-nav-link {
  display: inline-flex;
  flex: 0 1 auto;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.62rem 1.2rem;
  white-space: nowrap;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: rgba(10, 10, 15, 0.28);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
  transition: color var(--transition), border-color var(--transition),
    background var(--transition), box-shadow var(--transition),
    transform var(--transition);
}

.hero-nav-link:hover {
  color: var(--text);
  border-color: rgba(0, 212, 170, 0.45);
  background: rgba(124, 108, 249, 0.12);
  box-shadow: 0 0 0 1px rgba(124, 108, 249, 0.18),
    0 10px 28px rgba(0, 0, 0, 0.38);
  transform: translateY(-2px);
}

.hero-nav-link:active {
  transform: translateY(0) scale(0.98);
}

.hero-nav-link:focus-visible {
  outline: 2px solid rgba(0, 212, 170, 0.75);
  outline-offset: 3px;
  border-radius: 999px;
}

@media (max-width: 400px) {
  .hero-nav-btn--primary {
    padding-inline: 1.3rem;
    font-size: 0.92rem;
  }

  .hero-nav-link {
    font-size: 0.88rem;
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.6rem;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition),
    background var(--transition), border-color var(--transition);
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--gradient);
  color: #0a0a0f;
  box-shadow: 0 8px 32px rgba(124, 108, 249, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 12px 40px rgba(124, 108, 249, 0.45);
  color: #0a0a0f;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-subtle);
}

.btn-ghost:hover {
  border-color: rgba(255, 255, 255, 0.25);
  color: var(--text);
}

.btn-full {
  width: 100%;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 1.75rem;
  left: 50%;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.55rem;
  transform: translateX(-50%);
  pointer-events: none;
}

.hero-scroll-line {
  display: block;
  width: 2px;
  height: 48px;
  border-radius: 2px;
  background: linear-gradient(
    180deg,
    rgba(124, 108, 249, 0.15) 0%,
    var(--accent) 35%,
    var(--accent-2) 100%
  );
  box-shadow: 0 0 12px rgba(124, 108, 249, 0.45);
  animation: hero-scroll-line 1.8s ease-in-out infinite;
}

.hero-scroll-label {
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-muted);
  opacity: 0.9;
}

@keyframes hero-scroll-line {
  0%,
  100% {
    transform: translateY(0);
    opacity: 0.85;
  }
  50% {
    transform: translateY(10px);
    opacity: 1;
  }
}

/* ===== 섹션 공통 ===== */
.section {
  padding: 5rem 0;
}

.section-title {
  margin: 0 0 1rem;
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-lead {
  margin: 0 0 2.5rem;
  color: var(--text-muted);
  max-width: 900px;
}

.about-text {
  margin: 0;
  max-width: 980px;
  color: var(--text-muted);
  font-size: 1.05rem;
}

.about-text code {
  font-size: 0.9em;
  padding: 0.15rem 0.45rem;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--accent-2);
}

/* ===== 경험 타임라인 ===== */
.experience {
  border-top: 1px solid var(--border-subtle);
}

.experience-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 300px);
  gap: 2rem 2.5rem;
  align-items: start;
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: none;
}

.education-aside {
  position: relative;
  padding: 1.35rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.education-aside-title {
  margin: 0 0 1rem;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.04em;
}

.education-lines {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.education-line {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.education-line strong {
  display: block;
  margin-bottom: 0.2rem;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 4.25rem 1fr;
  gap: 1.25rem 1.5rem;
  padding-bottom: 2rem;
  padding-left: 0;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: 2rem;
  top: 0.35rem;
  bottom: 0;
  width: 2px;
  margin-left: -1px;
  background: linear-gradient(
    to bottom,
    rgba(124, 108, 249, 0.55),
    rgba(0, 212, 170, 0.25)
  );
  border-radius: 2px;
}

.timeline-item:last-child::before {
  bottom: auto;
  height: 1rem;
}

.timeline-year {
  position: relative;
  z-index: 1;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent-2);
}

.timeline-body {
  position: relative;
  padding: 1.1rem 1.35rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.timeline-heading {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
  font-weight: 600;
}

.timeline-desc {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ===== 자격증 · 수상 ===== */
.credentials {
  border-top: 1px solid var(--border-subtle);
}

.credentials-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.credential-card {
  padding: 1.5rem 1.5rem 1.35rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.credential-card-title {
  margin: 0 0 1rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.credential-list {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

.credential-list li + li {
  margin-top: 0.65rem;
}

/* ===== 기술 스택 ===== */
.skills {
  border-top: 1px solid var(--border-subtle);
}

.skill-groups {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.skill-group {
  padding: 1.35rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.skill-group-title {
  margin: 0 0 1rem;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.04em;
}

.skills-hover-hint {
  margin: -1.25rem 0 2.25rem;
  padding: 0.75rem 1.1rem;
  max-width: 900px;
  font-size: 0.92rem;
  line-height: 1.55;
  color: #c8e8e0;
  background: rgba(0, 212, 170, 0.07);
  border: 1px solid rgba(0, 212, 170, 0.28);
  border-radius: var(--radius);
}

.skills-hover-hint strong {
  color: var(--accent-2);
  font-weight: 600;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.skill-tags li {
  position: relative;
  font-size: 0.82rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border-subtle);
  background: rgba(124, 108, 249, 0.12);
  color: #dcd8ff;
  cursor: default;
  transition: border-color var(--transition), background var(--transition),
    box-shadow var(--transition);
}

.skill-tags li:hover,
.skill-tags li:focus-visible {
  border-color: rgba(124, 108, 249, 0.45);
  background: rgba(124, 108, 249, 0.2);
  box-shadow: 0 0 0 1px rgba(124, 108, 249, 0.2);
}

.skill-tags li:focus-visible {
  outline: none;
}

.skill-tags li[data-study]::after {
  content: attr(data-study);
  position: absolute;
  left: 50%;
  bottom: calc(100% + 0.55rem);
  z-index: 20;
  width: max-content;
  max-width: min(18rem, calc(100vw - 2rem));
  padding: 0.65rem 0.85rem;
  font-size: 0.78rem;
  font-weight: 400;
  line-height: 1.5;
  text-align: left;
  color: var(--text);
  word-break: keep-all;
  pointer-events: none;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(6px);
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease;
  border-radius: var(--radius);
  border: 1px solid rgba(124, 108, 249, 0.35);
  background: rgba(22, 22, 34, 0.97);
  box-shadow: var(--shadow);
}

.skill-tags li[data-study]:hover::after,
.skill-tags li[data-study]:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* ===== 프로젝트 카드 ===== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.project-card {
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: background var(--transition), border-color var(--transition),
    transform var(--transition);
}

.project-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(124, 108, 249, 0.35);
  transform: translateY(-4px);
}

.project-thumb {
  aspect-ratio: 16 / 10;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.25rem;
  background: rgba(255, 255, 255, 0.04);
}

.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-meta {
  margin-bottom: 0.75rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.project-tags li {
  font-size: 0.72rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.25rem 0.55rem;
  border-radius: 6px;
  background: rgba(124, 108, 249, 0.2);
  color: #c9c4ff;
}

.project-title {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
  font-weight: 600;
}

.project-desc {
  margin: 0 0 1.25rem;
  flex-grow: 1;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.link-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 500;
  border-radius: 999px;
  border: 1px solid var(--border-subtle);
  color: var(--text);
  transition: border-color var(--transition), background var(--transition);
}

.link-pill:hover {
  border-color: rgba(0, 212, 170, 0.5);
  background: rgba(0, 212, 170, 0.08);
  color: var(--accent-2);
}

.link-pill svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  opacity: 0.85;
}

.projects {
  border-top: 1px solid var(--border-subtle);
}

/* ===== 푸터 ===== */
.site-footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border-subtle);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.footer-copy {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-top {
  font-size: 0.9rem;
  color: var(--accent);
}

.footer-top:hover {
  color: var(--accent-2);
}

/* ===== 반응형 ===== */
@media (max-width: 1100px) {
  .skill-groups {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 960px) {
  .experience-layout {
    grid-template-columns: 1fr;
  }

  .education-aside {
    position: static;
    max-width: 480px;
  }

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

  .credentials-grid {
    grid-template-columns: 1fr;
  }

  .skill-groups {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #050509;
    padding: 1.5rem 1.5rem 1.75rem;
    border-bottom: 1px solid var(--border-subtle);
    box-shadow: 0 18px 45px rgba(0, 0, 0, 0.55);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-8px);
    transition: opacity var(--transition), transform var(--transition),
      visibility var(--transition);
    z-index: 99;
  }

  .site-header.is-open .site-nav {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    gap: 1.5rem;
  }

  .nav-list a {
    font-size: 1.25rem;
  }

  .header-datetime {
    min-width: 268px;
    gap: 0.65rem;
    font-size: 0.86rem;
    padding: 0.4rem 0.75rem;
  }

  .project-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding: 3rem 0 4rem;
  }

  .hero-scroll-hint {
    display: none;
  }
}

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

  .hero-bg__video {
    display: none;
  }

  .hero-scroll-line {
    animation: none;
  }

  .skill-tags li[data-study]::after {
    transition: none;
  }

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