:root {
  --bg: #f3f6f4;
  --bg-soft: #e8efe9;
  --ink: #12201a;
  --muted: #4d5f56;
  --accent: #0d7a5f;
  --accent-deep: #095c47;
  --warm: #e8a317;
  --line: #cfd9d2;
  --white: #ffffff;
  --font: 'Noto Sans KR', sans-serif;
  --display: 'Outfit', 'Noto Sans KR', sans-serif;
  --header: 72px;
  --max: 1080px;
  --ease: 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header);
}

body {
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(13, 122, 95, 0.08), transparent 60%),
    radial-gradient(900px 500px at 100% 20%, rgba(232, 163, 23, 0.08), transparent 55%),
    var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { display: block; width: 100%; height: 100%; object-fit: cover; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

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

/* Header */
.header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  height: var(--header);
  background: rgba(243, 246, 244, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--ease), background var(--ease);
}

.header.scrolled {
  border-bottom-color: var(--line);
  background: rgba(243, 246, 244, 0.95);
}

.nav {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 28px;
}

.logo {
  font-family: var(--display);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.03em;
  margin-right: auto;
}

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

.nav-menu {
  display: flex;
  gap: 28px;
}

.nav-menu a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--muted);
  transition: color var(--ease);
}

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

.nav-cta {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--accent-deep);
  padding: 8px 14px;
  border: 1.5px solid var(--accent);
  border-radius: 999px;
  transition: background var(--ease), color var(--ease);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  border: 0;
  background: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--ink);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 26px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform var(--ease), background var(--ease), color var(--ease), border-color var(--ease);
}

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

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

.btn-primary:hover { background: var(--accent-deep); }

.btn-ghost {
  border: 1.5px solid rgba(255, 255, 255, 0.55);
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.18);
  border-color: #fff;
}

/* Hero — full-bleed */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
}

.hero-media {
  position: absolute;
  inset: 0;
  background:
    url('images/hero-main.png')
    center 30% / cover no-repeat;
  animation: heroZoom 18s ease-in-out infinite alternate;
}

.hero-shade {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.72) 0%, rgba(232, 245, 240, 0.45) 42%, rgba(255, 255, 255, 0.08) 72%),
    linear-gradient(to top, rgba(243, 246, 244, 0.88) 0%, rgba(243, 246, 244, 0.2) 38%, transparent 58%);
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: calc(var(--header) + 80px) 0 88px;
  max-width: 720px;
  color: var(--ink);
  animation: riseIn 0.9s var(--ease) both;
}

.brand-mark {
  font-family: var(--display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 18px;
  color: var(--ink);
}

.brand-mark::after {
  content: '';
  display: block;
  width: 48px;
  height: 4px;
  margin-top: 14px;
  background: var(--warm);
  border-radius: 2px;
  animation: barGrow 0.8s 0.3s var(--ease) both;
}

.hero h1 {
  font-family: var(--display);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--muted);
  margin-bottom: 32px;
  max-width: 28em;
}

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

.hero .btn-ghost {
  border-color: var(--line);
  color: var(--ink);
  background: rgba(255, 255, 255, 0.65);
}

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

/* About */
.about {
  padding: 96px 0;
}

.about-inner {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 48px;
  align-items: end;
}

.label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.about h2,
.section-head h2,
.instructor h2,
.contact-panel h2 {
  font-family: var(--display);
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.about-copy p {
  margin-top: 18px;
  color: var(--muted);
  max-width: 36em;
}

.about-copy strong { color: var(--ink); }

.about-points {
  display: grid;
  gap: 12px;
}

.about-points li {
  padding: 16px 18px;
  background: var(--white);
  border-left: 3px solid var(--accent);
  font-weight: 600;
  box-shadow: 0 1px 0 rgba(18, 32, 26, 0.04);
}

/* Instructor accordion */
.instructor {
  padding: 0 0 80px;
}

.accordion {
  background: var(--white);
  border: 1px solid var(--line);
  overflow: hidden;
}

.accordion-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 32px;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  color: inherit;
  transition: background var(--ease);
}

.accordion-trigger:hover {
  background: var(--bg-soft);
}

.accordion-lead {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.accordion-lead .label {
  margin-bottom: 2px;
}

.accordion-title {
  font-family: var(--display);
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.accordion-desc {
  font-size: 0.92rem;
  color: var(--muted);
}

.accordion-icon {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1.5px solid var(--line);
  position: relative;
  transition: transform var(--ease), border-color var(--ease), background var(--ease);
}

.accordion-icon::before,
.accordion-icon::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 12px;
  height: 2px;
  background: var(--accent);
  transform: translate(-50%, -50%);
}

.accordion-icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
  transition: transform var(--ease), opacity var(--ease);
}

.accordion.open .accordion-icon {
  border-color: var(--accent);
  background: rgba(13, 122, 95, 0.08);
}

.accordion.open .accordion-icon::after {
  transform: translate(-50%, -50%) rotate(90deg) scaleY(0);
  opacity: 0;
}

.accordion-panel {
  border-top: 1px solid var(--line);
  padding: 0 32px 32px;
}

.accordion-panel[hidden] {
  display: none;
}

.profile {
  display: grid;
  gap: 28px;
  padding-top: 28px;
}

.profile-intro {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.profile-photo {
  flex-shrink: 0;
  width: 168px;
  height: 168px;
  object-fit: cover;
  object-position: center 20%;
  border-radius: 10px;
  background: var(--bg-soft);
}

.profile-intro h3 {
  font-family: var(--display);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.profile-role {
  margin-top: 4px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
}

.profile-summary {
  margin-top: 12px;
  color: var(--muted);
  max-width: 40em;
}

.profile-research {
  margin-top: 14px;
  font-size: 0.92rem;
  color: var(--ink);
  max-width: 42em;
  line-height: 1.6;
}

.profile-research a {
  color: var(--accent);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.profile-research a:hover {
  color: var(--accent-deep);
}

.profile-career {
  display: grid;
  gap: 16px;
}

.profile-career li {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.profile-career li:last-child { border-bottom: none; }

.profile-career strong {
  font-size: 0.85rem;
  color: var(--accent-deep);
}

.profile-career span {
  color: var(--muted);
  font-size: 0.95rem;
}


/* Curriculum */
.curriculum {
  padding: 20px 0 100px;
}

.section-head {
  margin-bottom: 40px;
}

.section-head p {
  margin-top: 10px;
  color: var(--muted);
}

.course-list {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.course {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 0;
  background: var(--white);
  overflow: hidden;
  border: 1px solid var(--line);
  transition: transform var(--ease), box-shadow var(--ease);
}

.course:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 40px rgba(18, 32, 26, 0.08);
}

.course:nth-child(even) .course-media { order: 2; }

.course-media {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--bg-soft);
}

.course-media img {
  transition: transform 0.7s var(--ease);
}

.course:hover .course-media img {
  transform: scale(1.04);
}

.course-body {
  padding: 36px 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.course-num {
  font-family: var(--display);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--warm);
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.course-body h3 {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.course-body h3 em {
  font-style: normal;
  font-weight: 600;
  font-size: 0.85em;
  color: var(--muted);
}

.course-body > p {
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.course-body ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.course-body li {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-deep);
  background: var(--bg-soft);
  padding: 6px 12px;
  border-radius: 999px;
}

/* Path */
.path {
  padding: 0 0 100px;
}

.path-track {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 10px;
}

.path-track li {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 22px 10px;
  text-align: center;
  position: relative;
  animation: riseIn 0.6s var(--ease) both;
}

.path-track li:nth-child(1) { animation-delay: 0.05s; }
.path-track li:nth-child(2) { animation-delay: 0.1s; }
.path-track li:nth-child(3) { animation-delay: 0.15s; }
.path-track li:nth-child(4) { animation-delay: 0.2s; }
.path-track li:nth-child(5) { animation-delay: 0.25s; }
.path-track li:nth-child(6) { animation-delay: 0.3s; }
.path-track li:nth-child(7) { animation-delay: 0.35s; }

.path-track strong {
  display: block;
  font-family: var(--display);
  font-size: 0.88rem;
  margin-bottom: 4px;
  line-height: 1.3;
}

.path-track span {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.35;
}

/* Contact */
.contact { padding-bottom: 100px; }

.contact-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 48px;
  background:
    linear-gradient(135deg, #0d7a5f 0%, #0a5c48 100%),
    var(--accent);
  color: #fff;
}

.contact-panel .label { color: var(--warm); }

.contact-panel p {
  margin-top: 10px;
  opacity: 0.9;
}

.contact-address {
  margin-top: 16px;
  font-size: 0.95rem;
  font-weight: 500;
  opacity: 1;
  line-height: 1.5;
}

.contact-call {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 14px;
  flex-shrink: 0;
}

.phone {
  font-family: var(--display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

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

.contact-call .btn-primary:hover {
  background: #f3f6f4;
}

/* Footer */
.footer {
  padding: 28px 0 36px;
  border-top: 1px solid var(--line);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.footer p {
  font-size: 0.85rem;
  color: var(--muted);
}

/* Motion */
@keyframes heroZoom {
  from { transform: scale(1); }
  to { transform: scale(1.06); }
}

@keyframes riseIn {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes barGrow {
  from { width: 0; opacity: 0; }
  to { width: 48px; opacity: 1; }
}

/* Responsive */
@media (max-width: 900px) {
  .about-inner,
  .course,
  .course:nth-child(even) {
    grid-template-columns: 1fr;
  }

  .course:nth-child(even) .course-media { order: 0; }

  .path-track {
    grid-template-columns: repeat(4, 1fr);
  }

  .contact-panel {
    flex-direction: column;
    align-items: flex-start;
    padding: 36px 28px;
  }

  .contact-call { align-items: flex-start; }
}

@media (max-width: 640px) {
  .accordion-trigger,
  .accordion-panel {
    padding-left: 20px;
    padding-right: 20px;
  }

  .profile-intro { flex-direction: column; }

  .profile-career li {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .nav-toggle { display: flex; }
  .nav-cta { display: none; }

  .nav-menu {
    position: fixed;
    top: var(--header);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 12px 20px 20px;
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: var(--ease);
  }

  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-menu li {
    padding: 12px 0;
    border-bottom: 1px solid var(--line);
  }

  .hero-content { padding-bottom: 64px; }

  .hero-actions .btn { width: 100%; }

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

  .course-body { padding: 24px 20px; }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}