:root {
  --bg: #fafbfc;
  --bg-soft: #eef5f5;
  --surface: #ffffff;
  --ink: #1a2328;
  --ink-muted: #5a6a72;
  --accent: #1f6f78;
  --accent-soft: #d7ebed;
  --accent-deep: #14545b;
  --line: #d8e2e5;
  --danger: #9b3b3b;
  --success: #2f6b4f;
  --radius: 10px;
  --shadow: 0 12px 40px rgba(26, 35, 40, 0.06);
  --font-display: "Gowun Batang", "Noto Serif KR", serif;
  --font-body: "Noto Sans KR", sans-serif;
  --space: clamp(1rem, 2vw, 1.5rem);
  --max: 1120px;
  --header-h: 4.25rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(31, 111, 120, 0.08), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(168, 213, 216, 0.25), transparent 50%),
    var(--bg);
  line-height: 1.7;
  min-height: 100vh;
}

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

a {
  color: var(--accent-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0 0 0.6em;
}

p {
  margin: 0 0 1em;
}

ul, ol {
  margin: 0 0 1em;
  padding-left: 1.2em;
}

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -100px;
  background: var(--accent);
  color: #fff;
  padding: 0.6rem 1rem;
  z-index: 1000;
  border-radius: 6px;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 251, 252, 0.88);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 4px 20px rgba(26, 35, 40, 0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 6px;
  background:
    linear-gradient(145deg, var(--accent) 0%, var(--accent-deep) 100%);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.2);
  animation: brandPulse 4s ease-in-out infinite;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: -0.03em;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.15rem 1.35rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  text-decoration: none;
  color: var(--ink-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-list a:hover,
.nav-list a[aria-current="page"] {
  color: var(--accent-deep);
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  width: 2.75rem;
  height: 2.75rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  padding: 0;
}

.nav-toggle-bar,
.nav-toggle-bar::before,
.nav-toggle-bar::after {
  display: block;
  width: 1.1rem;
  height: 2px;
  background: var(--ink);
  position: relative;
  transition: transform 0.2s ease;
}

.nav-toggle-bar::before,
.nav-toggle-bar::after {
  content: "";
  position: absolute;
  left: 0;
}

.nav-toggle-bar::before { top: -6px; }
.nav-toggle-bar::after { top: 6px; }

/* Hero — brand-forward split */
.hero-brand {
  padding: clamp(3rem, 8vw, 6.5rem) 0 clamp(2.5rem, 5vw, 4rem);
  overflow: hidden;
}

.hero-brand-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: end;
}

.hero-brand-label {
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
  font-weight: 600;
}

.hero-brand h1 {
  font-size: clamp(2.4rem, 5.5vw, 4.1rem);
  margin-bottom: 0.35em;
  color: var(--ink);
}

.hero-brand .brand-hero-name {
  display: block;
  font-size: clamp(2.8rem, 6.5vw, 4.8rem);
  color: var(--accent-deep);
  margin-bottom: 0.15em;
}

.hero-lead {
  font-size: 1.08rem;
  color: var(--ink-muted);
  max-width: 34ch;
  margin-bottom: 1.75rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-visual {
  position: relative;
  min-height: 360px;
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  min-height: 360px;
  border-radius: 0;
  animation: fadeRise 1s ease both;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 35%;
  background: linear-gradient(to top, var(--bg), transparent);
  pointer-events: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn:active {
  transform: translateY(1px);
}

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

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

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent-deep);
}

/* Sections */
.section {
  padding: clamp(3rem, 7vw, 5.5rem) 0;
}

.section-soft {
  background: var(--bg-soft);
}

.section-head {
  max-width: 38rem;
  margin-bottom: 2.5rem;
}

.section-head h2 {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
}

.section-head p {
  color: var(--ink-muted);
  margin: 0;
}

.eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.6rem;
}

/* Proof strip — early on home */
.proof-strip {
  border-block: 1px solid var(--line);
  padding: 1.75rem 0;
  background: var(--surface);
}

.proof-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  text-align: center;
}

.proof-item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.85rem;
  color: var(--accent-deep);
  letter-spacing: -0.02em;
}

.proof-item span {
  font-size: 0.88rem;
  color: var(--ink-muted);
}

/* Featured deep dive */
.feature-dive {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
}

.feature-dive img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

.feature-dive-body h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
}

.feature-dive-body p {
  color: var(--ink-muted);
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  font-size: 0.88rem;
  color: var(--ink-muted);
  margin: 1.25rem 0;
}

.meta-row span::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  margin-right: 0.45rem;
  vertical-align: middle;
}

/* Benefit list — not cards */
.benefit-list {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.benefit-row {
  display: grid;
  grid-template-columns: 4rem 1fr 1.2fr;
  gap: 1.5rem;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.benefit-row.is-visible {
  opacity: 1;
  transform: none;
}

.benefit-num {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--accent);
}

.benefit-row h3 {
  font-size: 1.2rem;
  margin: 0;
}

.benefit-row p {
  margin: 0;
  color: var(--ink-muted);
}

/* Course grid */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.course-item {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.course-item a {
  text-decoration: none;
  color: inherit;
}

.course-item img {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  transition: transform 0.45s ease;
}

.course-item:hover img {
  transform: scale(1.02);
}

.course-item h3 {
  font-size: 1.2rem;
  margin: 0 0 0.35em;
}

.course-item p {
  color: var(--ink-muted);
  font-size: 0.95rem;
  margin: 0;
}

.course-meta {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 600;
}

/* Testimonials */
.quote-stack {
  display: grid;
  gap: 2rem;
}

.quote-block {
  max-width: 40rem;
}

.quote-block.offset {
  margin-left: auto;
  text-align: right;
}

.quote-block blockquote {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 2vw, 1.45rem);
  line-height: 1.55;
  font-weight: 500;
}

.quote-block cite {
  font-style: normal;
  font-size: 0.9rem;
  color: var(--ink-muted);
}

.quote-block .stars {
  color: var(--accent);
  letter-spacing: 0.08em;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}

/* CTA band */
.cta-band {
  padding: clamp(3rem, 6vw, 4.5rem) 0;
  background:
    linear-gradient(120deg, var(--accent-deep), var(--accent));
  color: #fff;
}

.cta-band h2 {
  color: #fff;
  font-size: clamp(1.7rem, 3vw, 2.3rem);
}

.cta-band p {
  color: rgba(255, 255, 255, 0.88);
  max-width: 36rem;
}

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

.cta-band .btn-primary:hover {
  background: var(--accent-soft);
}

.cta-band .btn-ghost {
  border-color: rgba(255, 255, 255, 0.45);
  color: #fff;
}

.cta-band .btn-ghost:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

/* Page hero (inner) */
.page-hero {
  padding: clamp(2.5rem, 6vw, 4rem) 0 2rem;
}

.page-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
}

.page-hero p {
  color: var(--ink-muted);
  max-width: 42rem;
  font-size: 1.05rem;
}

.page-hero-media {
  margin-top: 2rem;
}

.page-hero-media img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
}

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.price-tier {
  padding: 2rem 1.75rem;
  border: 1px solid var(--line);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.price-tier.featured {
  border-color: var(--accent);
  box-shadow: var(--shadow);
  background: linear-gradient(180deg, #fff 0%, var(--bg-soft) 100%);
}

.price-tier h2 {
  font-size: 1.4rem;
  margin: 0;
}

.price-tier .price {
  font-family: var(--font-display);
  font-size: 2.2rem;
  color: var(--accent-deep);
}

.price-tier .price span {
  font-size: 0.95rem;
  font-family: var(--font-body);
  color: var(--ink-muted);
  font-weight: 400;
}

.price-tier ul {
  list-style: none;
  padding: 0;
  margin: 0 0 1rem;
  flex: 1;
}

.price-tier li {
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.95rem;
  color: var(--ink-muted);
}

.price-note {
  font-size: 0.88rem;
  color: var(--ink-muted);
  margin-top: 2rem;
}

/* Forms */
.form-layout {
  display: grid;
  grid-template-columns: 1fr 0.9fr;
  gap: clamp(2rem, 5vw, 3.5rem);
}

.contact-aside h2 {
  font-size: 1.3rem;
}

.contact-aside p,
.contact-aside address {
  color: var(--ink-muted);
  font-style: normal;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.8rem 0.95rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 1rem;
  background: var(--surface);
  color: var(--ink);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

.field-error {
  color: var(--danger);
  font-size: 0.85rem;
  margin-top: 0.35rem;
  display: none;
}

.form-group.has-error .field-error {
  display: block;
}

.form-group.has-error input,
.form-group.has-error select,
.form-group.has-error textarea {
  border-color: var(--danger);
}

.form-status {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius);
  display: none;
}

.form-status.is-success {
  display: block;
  background: #e8f4ee;
  color: var(--success);
}

.form-status.is-error {
  display: block;
  background: #f8eaea;
  color: var(--danger);
}

.inline-error {
  margin: 1rem 0;
  padding: 0.85rem 1rem;
  background: #f8eaea;
  color: var(--danger);
  border-radius: var(--radius);
}

/* Blog */
.blog-list {
  display: grid;
  gap: 2.5rem;
}

.blog-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.75rem;
  align-items: start;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--line);
}

.blog-row img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

.blog-row h2 {
  font-size: 1.35rem;
  margin-bottom: 0.4em;
}

.blog-row h2 a {
  text-decoration: none;
  color: var(--ink);
}

.blog-row h2 a:hover {
  color: var(--accent);
}

.blog-meta {
  font-size: 0.82rem;
  color: var(--ink-muted);
  margin-bottom: 0.6rem;
}

.prose {
  max-width: 42rem;
}

.prose h2 {
  margin-top: 2rem;
  font-size: 1.45rem;
}

.prose h3 {
  margin-top: 1.5rem;
  font-size: 1.15rem;
}

.prose img.cover {
  width: 100%;
  max-width: 720px;
  aspect-ratio: 16/9;
  object-fit: cover;
  margin: 1.5rem 0 2rem;
}

/* Course detail */
.module-list {
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--line);
}

.module-list li {
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 1rem;
}

.module-list .mod-num {
  font-family: var(--font-display);
  color: var(--accent);
  font-size: 1.1rem;
}

.instructor {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.5rem;
  align-items: start;
  margin: 2rem 0;
}

.instructor img {
  width: 120px;
  height: 120px;
  object-fit: cover;
  border-radius: 50%;
}

.faq-list details {
  border-bottom: 1px solid var(--line);
  padding: 1rem 0;
}

.faq-list summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  float: right;
  color: var(--accent);
  font-weight: 400;
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list details p {
  color: var(--ink-muted);
  margin: 0.75rem 0 0;
}

/* Reviews / case studies */
.case-study {
  padding: 2rem 0;
  border-top: 1px solid var(--line);
}

.case-study h3 {
  font-size: 1.35rem;
}

.rating-line {
  color: var(--accent);
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}

/* Legal */
.legal-doc {
  max-width: 46rem;
  padding-bottom: 3rem;
}

.legal-doc h2 {
  font-size: 1.35rem;
  margin-top: 2rem;
}

.legal-doc table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 1.25rem 0;
}

.legal-doc th,
.legal-doc td {
  border: 1px solid var(--line);
  padding: 0.65rem 0.75rem;
  text-align: left;
  vertical-align: top;
}

.legal-doc th {
  background: var(--bg-soft);
}

/* 404 */
.error-page {
  min-height: 60vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 4rem 1rem;
}

.error-page h1 {
  font-size: clamp(3rem, 8vw, 5rem);
  color: var(--accent);
  margin-bottom: 0.2em;
}

/* Cookie banner */
.cookie-banner {
  position: fixed;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  z-index: 200;
  max-width: 520px;
  margin-inline: auto;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 1.25rem 1.35rem;
  border-radius: 12px;
  display: none;
}

.cookie-banner.is-visible {
  display: block;
  animation: fadeRise 0.35s ease;
}

.cookie-banner p {
  font-size: 0.92rem;
  color: var(--ink-muted);
  margin-bottom: 1rem;
}

.cookie-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.cookie-actions .btn {
  padding: 0.65rem 1.1rem;
  font-size: 0.88rem;
}

/* Footer */
.site-footer {
  background: #152024;
  color: rgba(255, 255, 255, 0.78);
  padding: 3.5rem 0 1.5rem;
  margin-top: 2rem;
}

.site-footer a {
  color: rgba(255, 255, 255, 0.78);
  text-decoration: none;
}

.site-footer a:hover {
  color: #fff;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.3fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: #fff;
  margin-bottom: 0.6rem;
}

.footer-tag {
  font-size: 0.9rem;
  max-width: 28ch;
}

.footer-heading {
  color: #fff;
  font-weight: 600;
  font-size: 0.88rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 0.85rem;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col li {
  margin-bottom: 0.45rem;
}

.footer-address {
  font-style: normal;
  font-size: 0.88rem;
  line-height: 1.55;
  margin-bottom: 0.75rem;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 1.25rem;
  font-size: 0.85rem;
}

/* Topic page accent */
.topic-panel {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.topic-panel > div {
  padding: 1.5rem 0;
  border-top: 2px solid var(--accent);
}

.topic-panel h3 {
  font-size: 1.15rem;
}

.topic-panel p {
  color: var(--ink-muted);
  margin: 0;
}

/* Animations */
@keyframes fadeRise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes brandPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.85; }
}

@media (max-width: 900px) {
  .hero-brand-grid,
  .feature-dive,
  .form-layout,
  .pricing-grid,
  .course-grid,
  .footer-grid,
  .topic-panel {
    grid-template-columns: 1fr;
  }

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

  .benefit-row {
    grid-template-columns: 3rem 1fr;
  }

  .benefit-row p {
    grid-column: 1 / -1;
  }

  .blog-row {
    grid-template-columns: 1fr;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: var(--header-h);
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    padding: 1rem 1.25rem 1.25rem;
    display: none;
  }

  .site-nav.is-open {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    gap: 0.85rem;
  }

  .quote-block.offset {
    text-align: left;
    margin-left: 0;
  }
}

@media (max-width: 560px) {
  .proof-grid {
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
  }

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