:root {
  --navy: #0f2742;
  --navy-dark: #081827;
  --blue: #2563eb;
  --blue-soft: #e8f0ff;
  --white: #ffffff;
  --gray-50: #f7f9fc;
  --gray-100: #edf1f7;
  --gray-300: #c9d3df;
  --gray-600: #5b6b7d;
  --gray-800: #243244;
  --shadow: 0 18px 45px rgba(15, 39, 66, 0.09);
  --shadow-strong: 0 26px 70px rgba(8, 24, 39, 0.18);
  --radius: 8px;
  --container: 1160px;
  --section: 96px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  color: var(--gray-800);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans KR", Arial, sans-serif;
  line-height: 1.7;
  background: var(--white);
  word-break: keep-all;
  overflow-x: hidden;
}

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

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

p,
h1,
h2,
h3 {
  margin-top: 0;
}

p {
  margin-bottom: 0;
}

ul {
  margin: 0;
  padding: 0;
}

.container {
  width: min(100% - 40px, var(--container));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--gray-100);
  backdrop-filter: blur(14px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 74px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  color: var(--navy);
  white-space: nowrap;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: var(--white);
  background: var(--navy);
  border-radius: var(--radius);
  font-size: 0.84rem;
}

.brand-text {
  font-size: 1rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 18px;
  list-style: none;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--gray-600);
}

.nav-menu a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  transition: color 0.2s ease;
}

.nav-menu a:hover,
.nav-menu a:focus {
  color: var(--blue);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius);
  background: var(--white);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: var(--navy);
}

.section {
  padding: var(--section) 0;
}

.section-muted {
  background: var(--gray-50);
}

.hero {
  min-height: calc(100vh - 74px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: var(--white);
  background:
    linear-gradient(120deg, rgba(8, 24, 39, 0.96), rgba(15, 39, 66, 0.88)),
    url("../images/bgimage.jpg") center/cover no-repeat;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: 56px;
  align-items: center;
}

.eyebrow {
  margin-bottom: 14px;
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #8bb8ff;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(3rem, 8vw, 5.7rem);
  line-height: 1.05;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 14px;
  color: var(--navy);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.2;
}

h3 {
  margin-bottom: 14px;
  color: var(--navy);
  font-size: 1.15rem;
  line-height: 1.35;
}

.headline {
  max-width: 760px;
  margin-bottom: 18px;
  color: #eef5ff;
  font-size: clamp(1.35rem, 3vw, 2.1rem);
  font-weight: 700;
  line-height: 1.4;
}

.hero-copy {
  max-width: 780px;
  color: #d8e6f7;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 28px 0 32px;
}

.hero-tags span,
.education-strip span {
  padding: 8px 12px;
  border-radius: var(--radius);
  color: var(--navy);
  background: var(--blue-soft);
  font-size: 0.86rem;
  font-weight: 700;
}

.hero-tags span {
  color: #eaf2ff;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

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

.btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  border-radius: var(--radius);
  font-weight: 800;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover,
.btn:focus {
  transform: translateY(-2px);
}

.btn.primary {
  background: var(--blue);
  color: var(--white);
  box-shadow: 0 12px 28px rgba(37, 99, 235, 0.35);
}

.btn.secondary {
  background: var(--white);
  color: var(--navy);
}

.hero-panel {
  display: grid;
  gap: 18px;
}

.hero-panel div {
  padding: 28px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.1);
  box-shadow: var(--shadow-strong);
}

.metric {
  display: block;
  margin-bottom: 6px;
  color: var(--white);
  font-size: 2.35rem;
  font-weight: 900;
  line-height: 1;
}

.trust-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin-top: 56px;
  overflow: hidden;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.2);
}

.trust-bar div {
  min-height: 98px;
  padding: 22px;
  background: rgba(255, 255, 255, 0.1);
}

.trust-bar strong {
  display: block;
  margin-bottom: 4px;
  color: var(--white);
}

.trust-bar span {
  color: #d8e6f7;
  font-size: 0.92rem;
}

.section-heading {
  max-width: 780px;
  margin-bottom: 40px;
}

.section-heading p:not(.eyebrow) {
  color: var(--gray-600);
  font-size: 1.05rem;
}

.card {
  padding: 28px;
  border: 1px solid var(--gray-100);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.profile-layout,
.company-layout,
.mentoring-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.6fr;
  gap: 28px;
  align-items: start;
}

.profile-photo img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  border-radius: var(--radius);
  background: var(--gray-100);
}

.profile-photo figcaption {
  margin-top: 16px;
  color: var(--gray-600);
  font-size: 0.92rem;
}

.split-grid,
.card-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.wide-card,
.card-list .card {
  grid-column: 1 / -1;
}

.info-list,
.project-card dl {
  margin: 0;
}

.info-list div,
.project-card dl div {
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 14px;
  padding: 9px 0;
  border-bottom: 1px solid var(--gray-100);
}

.info-list div:last-child,
.project-card dl div:last-child {
  border-bottom: 0;
}

dt {
  color: var(--navy);
  font-weight: 800;
}

dd {
  margin: 0;
  color: var(--gray-600);
}

.check-list {
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 24px;
  margin-bottom: 10px;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--blue);
}

.emphasis-card {
  min-height: 100%;
  background: var(--navy);
  color: #d8e6f7;
}

.emphasis-card h3,
.emphasis-card .role-title {
  color: var(--white);
}

.role-title {
  margin-bottom: 10px;
  color: var(--blue);
  font-weight: 800;
}

.media-card {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 20px;
  align-items: center;
}

.media-card img {
  width: 100%;
  object-fit: cover;
  border-radius: var(--radius);
}

.timeline {
  position: relative;
  display: grid;
  gap: 24px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 142px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--gray-100);
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 48px;
}

.timeline-date {
  color: var(--navy);
  font-weight: 900;
}

.timeline-content::before {
  content: "";
  position: absolute;
  left: 135px;
  top: 12px;
  width: 16px;
  height: 16px;
  border: 4px solid var(--blue-soft);
  border-radius: 50%;
  background: var(--blue);
}

.ai-practice-section {
  background: linear-gradient(180deg, var(--gray-50) 0%, var(--blue-soft) 100%);
}

.ai-practice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.ai-practice-card {
  position: relative;
  min-width: 0;
  border-top: 3px solid var(--blue);
}

.practice-index {
  margin-bottom: 12px;
  color: var(--blue);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.ai-practice-card h3 {
  margin-bottom: 10px;
  color: var(--navy);
}

.ai-practice-card > p:last-child {
  color: var(--gray-600);
}

.practice-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.practice-step {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 12px;
  padding: 18px 20px;
  color: var(--white);
  border-radius: var(--radius);
  background: var(--navy);
}

.practice-step span {
  color: #8bb4ff;
  font-size: 0.78rem;
  font-weight: 900;
}

.practice-step strong {
  font-size: 0.95rem;
}

.cert-grid,
.skill-matrix,
.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.cert-card span {
  display: inline-flex;
  margin-bottom: 12px;
  color: var(--blue);
  font-size: 0.82rem;
  font-weight: 900;
}

.education-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.three-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.gallery-grid > figure,
.gallery-item {
  position: relative;
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--navy);
  min-height: 220px;
}

.gallery-item {
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.gallery-item:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}

.gallery-item img {
  width: 100%;
  object-fit: cover;
  transition: transform 0.2s ease;
}

.gallery-item:hover img,
.gallery-item:focus-visible img {
  transform: scale(1.025);
}

.gallery-caption {
  position: absolute;
  left: 14px;
  bottom: 14px;
  padding: 6px 10px;
  border-radius: var(--radius);
  color: var(--white);
  background: rgba(8, 24, 39, 0.78);
  font-size: 0.86rem;
  font-weight: 800;
}

.image-lightbox {
  width: min(1100px, calc(100% - 40px));
  max-width: none;
  max-height: calc(100% - 40px);
  padding: 0;
  overflow: visible;
  border: 0;
  border-radius: var(--radius);
  background: transparent;
}

.image-lightbox::backdrop {
  background: rgba(8, 24, 39, 0.88);
}

.lightbox-panel {
  position: relative;
  padding: 24px;
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-strong);
}

.lightbox-close {
  position: absolute;
  z-index: 1;
  top: 12px;
  right: 12px;
  display: grid;
  width: 44px;
  height: 44px;
  padding: 0;
  place-items: center;
  border: 0;
  border-radius: 50%;
  color: var(--white);
  background: rgba(8, 24, 39, 0.86);
  font-size: 1.8rem;
  line-height: 1;
  cursor: pointer;
}

.lightbox-close:hover,
.lightbox-close:focus-visible {
  background: var(--blue);
}

.lightbox-figure {
  margin: 0;
}

.lightbox-image {
  width: auto;
  max-width: 100%;
  max-height: calc(100vh - 150px);
  margin-inline: auto;
  object-fit: contain;
}

.lightbox-caption {
  margin-top: 14px;
  color: var(--gray-600);
  text-align: center;
  font-weight: 800;
}

.placeholder {
  display: grid;
  place-items: center;
  min-height: 220px;
  border: 1px dashed var(--gray-300);
  background: linear-gradient(135deg, var(--gray-50), var(--blue-soft));
  color: var(--navy);
  font-weight: 900;
}

.site-footer {
  padding: 32px 0;
  color: #d8e6f7;
  background: var(--navy-dark);
}

.footer-grid {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.footer-grid a {
  color: var(--white);
  font-weight: 800;
}

@media (max-width: 980px) {
  :root {
    --section: 72px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-menu {
    position: absolute;
    left: 20px;
    right: 20px;
    top: 74px;
    display: none;
    grid-template-columns: repeat(2, 1fr);
    gap: 4px;
    padding: 16px;
    border: 1px solid var(--gray-100);
    border-radius: var(--radius);
    background: var(--white);
    box-shadow: var(--shadow);
  }

  .nav-menu.is-open {
    display: grid;
  }

  .nav-menu a {
    padding: 6px 8px;
  }

  .hero-grid,
  .profile-layout,
  .company-layout,
  .mentoring-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .trust-bar,
  .ai-practice-grid,
  .cert-grid,
  .skill-matrix,
  .portfolio-grid,
  .three-grid,
  .gallery-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 680px) {
  .container {
    width: min(100% - 28px, var(--container));
  }

  .section {
    padding: 60px 0;
  }

  .split-grid,
  .card-list,
  .trust-bar,
  .ai-practice-grid,
  .cert-grid,
  .skill-matrix,
  .portfolio-grid,
  .three-grid,
  .gallery-grid {
    grid-template-columns: 1fr;
  }

  .practice-flow {
    grid-template-columns: 1fr;
  }

  .hero-grid {
    gap: 32px;
  }

  .card,
  .hero-panel div {
    padding: 22px;
  }

  .image-lightbox {
    width: calc(100% - 24px);
    max-height: calc(100% - 24px);
  }

  .lightbox-panel {
    padding: 12px;
  }

  .lightbox-image {
    max-height: calc(100vh - 120px);
  }

  .media-card {
    grid-template-columns: 1fr;
  }

  .timeline::before,
  .timeline-content::before {
    display: none;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .info-list div,
  .project-card dl div {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .footer-grid {
    align-items: flex-start;
    flex-direction: column;
  }
}

.lecture-category-grid {
  margin-bottom: 3rem;
}

.lecture-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.lecture-card {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.lecture-card-wide {
  grid-column: 1 / -1;
}

.lecture-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-border, #dfe5ec);
}

.lecture-card-header h3 {
  margin: 0.25rem 0 0;
}

.lecture-date {
  margin: 0;
  color: var(--color-blue, #2563eb);
  font-size: 0.875rem;
  font-weight: 700;
}

.lecture-location {
  margin: 0;
  color: var(--color-gray-600, #5f6b7a);
  font-size: 0.9rem;
  line-height: 1.6;
  text-align: right;
}

.lecture-content h4 {
  margin: 0 0 0.875rem;
  font-size: 1rem;
}

.lecture-topics {
  margin: 0;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

@media (max-width: 768px) {
  .lecture-list {
    grid-template-columns: 1fr;
  }

  .lecture-card-wide {
    grid-column: auto;
  }

  .lecture-card-header {
    flex-direction: column;
    gap: 0.75rem;
  }

  .lecture-location {
    text-align: left;
  }
}