/* Data Advance — minimalist teal accent on clean white */
:root {
  --bg: #ffffff;
  --bg-soft: #f4faf9;
  --bg-muted: #e8f4f2;
  --ink: #14231f;
  --ink-soft: #3d524c;
  --muted: #6b7f78;
  --line: #d5e5e1;
  --accent: #0f766e;
  --accent-deep: #0b5c56;
  --accent-soft: #99f6e4;
  --accent-wash: #ccfbf1;
  --danger: #b42318;
  --success: #067647;
  --radius: 4px;
  --shadow: 0 18px 40px rgba(15, 61, 55, 0.08);
  --font-display: "Fraunces", "Noto Serif KR", Georgia, serif;
  --font-body: "Noto Sans KR", "IBM Plex Sans KR", sans-serif;
  --max: 1120px;
  --header-h: 72px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--ink);
  background: var(--bg);
  background-image:
    radial-gradient(ellipse 80% 50% at 100% -10%, rgba(153, 246, 228, 0.35), transparent 55%),
    radial-gradient(ellipse 60% 40% at -10% 20%, rgba(204, 251, 241, 0.45), transparent 50%);
  background-attachment: fixed;
  min-height: 100vh;
}

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

a {
  color: var(--accent-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 560;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 0 0 0.6em;
}

h1 {
  font-size: clamp(2.2rem, 4.5vw, 3.4rem);
}

h2 {
  font-size: clamp(1.6rem, 3vw, 2.25rem);
}

h3 {
  font-size: 1.25rem;
}

p {
  margin: 0 0 1rem;
  color: var(--ink-soft);
}

.sr-only {
  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: var(--radius);
}

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

.container {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

.runtime-error {
  background: #fef3f2;
  color: var(--danger);
  padding: 0.75rem 1.25rem;
  text-align: center;
  font-size: 0.95rem;
  border-bottom: 1px solid #fecdca;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

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

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.logo-mark {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(145deg, var(--accent) 0%, #14b8a6 100%);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.25);
  position: relative;
}

.logo-mark::after {
  content: "";
  position: absolute;
  inset: 7px 7px 7px 10px;
  border-left: 2px solid #ecfeff;
  border-bottom: 2px solid #ecfeff;
  transform: skewX(-12deg);
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.2rem;
}

.site-nav .nav-list {
  display: flex;
  align-items: center;
  gap: 0.35rem 1.1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 0.95rem;
  font-weight: 500;
}

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

.nav-cta {
  background: var(--accent);
  color: #fff !important;
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
}

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

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--line);
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  cursor: pointer;
  position: relative;
}

.nav-toggle-bar,
.nav-toggle-bar::before,
.nav-toggle-bar::after {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  margin: 0 auto;
  position: relative;
}

.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;
}

@media (max-width: 900px) {
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: var(--header-h);
    background: #fff;
    border-bottom: 1px solid var(--line);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.28s ease;
  }

  .site-nav.is-open {
    max-height: 420px;
  }

  .site-nav .nav-list {
    flex-direction: column;
    align-items: stretch;
    padding: 1rem 1.25rem 1.4rem;
    gap: 0.2rem;
  }

  .site-nav a {
    display: block;
    padding: 0.65rem 0.4rem;
  }

  .nav-cta {
    text-align: center;
    margin-top: 0.4rem;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-size: 0.98rem;
  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);
}

.btn-text {
  background: transparent;
  color: var(--accent-deep);
  padding-inline: 0.4rem;
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* Hero variants */
.hero-path {
  padding: 3.5rem 0 2.5rem;
  overflow: hidden;
}

.hero-path-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2.5rem;
  align-items: end;
}

.brand-signal {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 0.95;
  color: var(--ink);
  margin: 0 0 1.5rem;
}

.brand-signal span {
  display: block;
  color: var(--accent);
}

.hero-lede {
  font-size: 1.15rem;
  max-width: 34ch;
  margin-bottom: 1.75rem;
}

.hero-visual {
  position: relative;
  min-height: 360px;
  border-radius: 2px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  min-height: 360px;
  animation: rise-in 0.9s ease both;
}

.path-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 2rem;
  list-style: none;
  padding: 0;
}

.path-rail li {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  padding: 0.45rem 0.85rem;
  font-size: 0.88rem;
  color: var(--ink-soft);
  animation: fade-up 0.6s ease both;
}

.path-rail li:nth-child(2) {
  animation-delay: 0.08s;
}
.path-rail li:nth-child(3) {
  animation-delay: 0.16s;
}
.path-rail li:nth-child(4) {
  animation-delay: 0.24s;
}
.path-rail li:nth-child(5) {
  animation-delay: 0.32s;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: scale(1.04);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 860px) {
  .hero-path-grid {
    grid-template-columns: 1fr;
  }
  .hero-visual {
    order: -1;
    min-height: 260px;
  }
  .hero-visual img {
    min-height: 260px;
  }
}

/* Sections */
.section {
  padding: 4.5rem 0;
}

.section-soft {
  background: var(--bg-soft);
  border-block: 1px solid var(--line);
}

.section-head {
  max-width: 40rem;
  margin-bottom: 2.25rem;
}

.section-head p {
  margin-bottom: 0;
}

.eyebrow {
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

/* Proof strip */
.proof-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding: 2rem 0 0;
}

.proof-item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--ink);
  letter-spacing: -0.03em;
}

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

@media (max-width: 700px) {
  .proof-strip {
    grid-template-columns: 1fr;
  }
}

/* Course cards — interaction containers */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.course-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.course-card:hover {
  border-color: var(--accent-soft);
  box-shadow: var(--shadow);
}

.course-card img {
  aspect-ratio: 16 / 10;
  object-fit: cover;
  width: 100%;
}

.course-card-body {
  padding: 1.25rem 1.3rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.course-card h3 {
  margin: 0;
  font-size: 1.15rem;
  color: var(--ink);
}

.course-card p {
  margin: 0;
  font-size: 0.95rem;
  flex: 1;
}

.course-meta {
  font-size: 0.85rem;
  color: var(--muted);
}

@media (max-width: 900px) {
  .course-grid {
    grid-template-columns: 1fr;
  }
}

/* Benefit list */
.benefit-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem 3rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.benefit-list li {
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.benefit-list h3 {
  margin-bottom: 0.4rem;
}

@media (max-width: 700px) {
  .benefit-list {
    grid-template-columns: 1fr;
  }
}

/* Testimonials */
.quote-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 1.5rem;
}

.quote {
  background: #fff;
  border-left: 3px solid var(--accent);
  padding: 1.5rem 1.6rem;
}

.quote p {
  font-size: 1.05rem;
  color: var(--ink);
}

.quote footer {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
}

@media (max-width: 800px) {
  .quote-grid {
    grid-template-columns: 1fr;
  }
}

/* CTA band */
.cta-band {
  padding: 4rem 0;
  text-align: center;
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.08), rgba(153, 246, 228, 0.25)),
    var(--bg-soft);
  border-block: 1px solid var(--line);
}

.cta-band h2 {
  max-width: 18ch;
  margin-inline: auto;
}

.cta-band p {
  max-width: 42ch;
  margin-inline: auto;
  margin-bottom: 1.5rem;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

/* Page hero (inner) */
.page-hero {
  padding: 3rem 0 2rem;
}

.page-hero h1 {
  max-width: 18ch;
}

.page-hero .lede {
  max-width: 48ch;
  font-size: 1.1rem;
}

.page-hero-media {
  margin-top: 2rem;
  border-radius: 2px;
  overflow: hidden;
  max-height: 380px;
}

.page-hero-media img {
  width: 100%;
  height: 380px;
  object-fit: cover;
}

/* Pricing */
.price-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  align-items: stretch;
}

.price-tier {
  background: #fff;
  border: 1px solid var(--line);
  padding: 1.75rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.price-tier.is-featured {
  border-color: var(--accent);
  box-shadow: var(--shadow);
  background: linear-gradient(180deg, #fff 0%, var(--accent-wash) 160%);
}

.price-tier h2 {
  font-size: 1.35rem;
  margin: 0;
}

.price-amount {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--ink);
  letter-spacing: -0.03em;
}

.price-amount small {
  font-size: 0.95rem;
  color: var(--muted);
  font-family: var(--font-body);
}

.price-tier ul {
  margin: 0.5rem 0 1rem;
  padding-left: 1.1rem;
  color: var(--ink-soft);
  flex: 1;
}

.price-tier li {
  margin-bottom: 0.4rem;
}

.price-note {
  font-size: 0.9rem;
  color: var(--muted);
  margin-top: 1.5rem;
}

@media (max-width: 900px) {
  .price-grid {
    grid-template-columns: 1fr;
  }
}

/* Forms */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 2.5rem;
}

.contact-details dt {
  font-weight: 700;
  margin-top: 1rem;
  color: var(--ink);
}

.contact-details dd {
  margin: 0.25rem 0 0;
  color: var(--ink-soft);
}

.form-group {
  margin-bottom: 1.1rem;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.35rem;
  font-size: 0.95rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  background: #fff;
  color: var(--ink);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}

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

.field-error {
  display: block;
  color: var(--danger);
  font-size: 0.88rem;
  margin-top: 0.3rem;
  min-height: 1.2em;
}

.form-status {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius);
}

.form-status.is-success {
  background: #ecfdf3;
  color: var(--success);
}

.form-status.is-error {
  background: #fef3f2;
  color: var(--danger);
}

@media (max-width: 800px) {
  .contact-layout {
    grid-template-columns: 1fr;
  }
}

/* Blog */
.blog-list {
  display: grid;
  gap: 1.75rem;
}

.blog-item {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.5rem;
  align-items: start;
  text-decoration: none;
  color: inherit;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--line);
}

.blog-item img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 2px;
}

.blog-item h2 {
  font-size: 1.35rem;
  margin-bottom: 0.4rem;
  color: var(--ink);
}

.blog-meta {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

@media (max-width: 700px) {
  .blog-item {
    grid-template-columns: 1fr;
  }
}

.prose {
  max-width: 42rem;
}

.prose h2 {
  margin-top: 2.2rem;
}

.prose ul,
.prose ol {
  color: var(--ink-soft);
  padding-left: 1.25rem;
}

.prose li {
  margin-bottom: 0.45rem;
}

.article-cover {
  margin: 1.5rem 0 2rem;
  border-radius: 2px;
  overflow: hidden;
}

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

/* Legal */
.legal-doc {
  max-width: 48rem;
  padding-bottom: 4rem;
}

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

.legal-doc table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 1rem 0 1.5rem;
}

.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);
}

/* Course detail */
.module-list {
  list-style: none;
  padding: 0;
  margin: 0;
  counter-reset: mod;
}

.module-list li {
  counter-increment: mod;
  padding: 1.1rem 0 1.1rem 3rem;
  border-bottom: 1px solid var(--line);
  position: relative;
}

.module-list li::before {
  content: counter(mod, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 1.1rem;
  font-family: var(--font-display);
  color: var(--accent);
  font-weight: 600;
}

.instructor {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.25rem;
  align-items: center;
  margin: 1.5rem 0;
}

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

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

.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--ink);
}

.faq details p {
  margin: 0.75rem 0 0;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

@media (max-width: 800px) {
  .two-col,
  .instructor {
    grid-template-columns: 1fr;
  }
}

/* Reviews / case studies */
.case-study {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  padding: 1.75rem;
  margin-bottom: 1.5rem;
}

.rating {
  color: var(--accent);
  letter-spacing: 0.08em;
  font-size: 0.9rem;
}

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

.error-page .code {
  font-family: var(--font-display);
  font-size: 5rem;
  color: var(--accent);
  line-height: 1;
  margin: 0;
}

/* Footer */
.site-footer {
  background: #0c1f1c;
  color: #c5d9d4;
  padding: 3.5rem 0 1.5rem;
  margin-top: 2rem;
}

.site-footer a {
  color: #e7f7f3;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--accent-soft);
}

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

.footer-logo {
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: #fff;
  margin-bottom: 0.4rem;
}

.footer-tag {
  color: #8fb3ab;
  font-size: 0.9rem;
}

.footer-contact {
  font-size: 0.88rem;
  color: #a8c4bd;
  margin-bottom: 0.4rem;
}

.footer-heading {
  color: #fff;
  font-weight: 700;
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
}

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

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

.footer-col a {
  font-size: 0.92rem;
  color: #b7d0c9;
}

.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.85rem;
  color: #7a9a92;
}

@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

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

/* Cookie banner */
.cookie-banner {
  position: fixed;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  z-index: 200;
  max-width: 640px;
  margin-inline: auto;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  border-radius: 8px;
  animation: fade-up 0.35s ease both;
}

.cookie-banner-inner {
  padding: 1.15rem 1.25rem;
}

.cookie-banner-inner p {
  margin: 0 0 1rem;
  font-size: 0.95rem;
}

.cookie-banner-actions {
  display: flex;
  gap: 0.6rem;
  justify-content: flex-end;
  flex-wrap: wrap;
}

/* Misc */
.split-media {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
}

.split-media img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  border-radius: 2px;
}

@media (max-width: 800px) {
  .split-media {
    grid-template-columns: 1fr;
  }
}

.tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent-deep);
  background: var(--accent-wash);
  padding: 0.2rem 0.55rem;
  border-radius: 3px;
}

.outcome-list {
  display: grid;
  gap: 0.75rem;
  list-style: none;
  padding: 0;
}

.outcome-list li {
  padding-left: 1.4rem;
  position: relative;
  color: var(--ink-soft);
}

.outcome-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 0.55rem;
  height: 0.55rem;
  background: var(--accent);
  border-radius: 1px;
}