:root {
  --bg: #f8f8f6;
  --surface: #ffffff;
  --ink: #1c1c1a;
  --muted: #5f5f5a;
  --line: #e4e2dc;
  --accent: #3d5a5b;
  --accent-soft: #e8efef;
  --accent-hover: #2f4849;
  --warm: #c4b8a5;
  --success: #2f6b4f;
  --danger: #8b3a3a;
  --radius: 4px;
  --shadow: 0 1px 0 rgba(28, 28, 26, 0.04);
  --font-display: "Song Myung", "Nanum Myeongjo", serif;
  --font-body: "IBM Plex Sans KR", "Noto 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: 1rem;
  line-height: 1.7;
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 100% 0%, rgba(61, 90, 91, 0.06), transparent 55%),
    radial-gradient(ellipse 60% 40% at 0% 20%, rgba(196, 184, 165, 0.12), transparent 50%),
    var(--bg);
  min-height: 100vh;
}

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

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

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

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 0 0 0.6em;
}

h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
}

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

h3 {
  font-size: 1.35rem;
}

p {
  margin: 0 0 1em;
  color: var(--muted);
}

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

.inline-error {
  background: #f8eaea;
  color: var(--danger);
  padding: 0.75rem 1.25rem;
  font-size: 0.9rem;
  border-bottom: 1px solid #e8cfcf;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(248, 248, 246, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

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

.logo {
  font-family: var(--font-display);
  font-size: 1.55rem;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: 0.02em;
}

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

.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  padding: 0.45rem 0.7rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-body);
  color: var(--ink);
}

@media (max-width: 880px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    position: absolute;
    left: 0;
    right: 0;
    top: var(--header-h);
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    padding: 0.5rem 0;
  }

  .nav.is-open {
    display: flex;
  }

  .nav a {
    padding: 0.85rem 1.25rem;
    border-top: 1px solid var(--line);
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.75rem 1.35rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.25s ease;
}

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

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

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

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

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

/* Hero */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: grid;
  align-items: end;
  overflow: hidden;
}

.hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  animation: heroDrift 18s ease-in-out infinite alternate;
}

.hero__shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(248, 248, 246, 0.15) 0%,
    rgba(28, 28, 26, 0.45) 45%,
    rgba(28, 28, 26, 0.78) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 1;
  padding: 4.5rem 0 3.5rem;
  color: #f8f8f6;
  max-width: 36rem;
  animation: riseIn 0.9s ease both;
}

.hero__brand {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 5rem);
  margin: 0 0 0.35em;
  color: #fff;
  line-height: 1.05;
}

.hero__lead {
  color: rgba(248, 248, 246, 0.88);
  font-size: 1.08rem;
  margin: 0;
}

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

.hero .btn--primary:hover {
  background: var(--accent-soft);
  color: var(--ink);
}

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

@keyframes heroDrift {
  from {
    transform: scale(1.02) translateY(0);
  }
  to {
    transform: scale(1.08) translateY(-1.5%);
  }
}

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

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.reveal {
  animation: fadeUp 0.7s ease both;
}

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

.section--tight {
  padding: 3rem 0;
}

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

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

.section__head p {
  margin-bottom: 0;
}

.eyebrow {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
  font-family: var(--font-body);
}

/* Proof strip */
.proof {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding: 2.5rem 0;
  border-bottom: 1px solid var(--line);
}

.proof__item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 400;
  color: var(--ink);
}

.proof__item span {
  color: var(--muted);
  font-size: 0.92rem;
}

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

/* Course / content grids */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

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

@media (max-width: 900px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }
  .grid-2 {
    grid-template-columns: 1fr;
  }
}

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

.course-item__media {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--accent-soft);
}

.course-item__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

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

.course-item h3 {
  margin-bottom: 0.25em;
}

.course-item h3 a {
  color: var(--ink);
  text-decoration: none;
}

.course-item h3 a:hover {
  color: var(--accent);
}

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

/* Benefits */
.benefit-list {
  display: grid;
  gap: 1.75rem;
  counter-reset: benefit;
}

.benefit-list article {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid var(--line);
}

.benefit-list article:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.benefit-list article::before {
  counter-increment: benefit;
  content: counter(benefit, decimal-leading-zero);
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--accent);
  line-height: 1.2;
}

/* Testimonials */
.quote {
  border-left: 2px solid var(--accent);
  padding: 0.25rem 0 0.25rem 1.25rem;
}

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

.quote footer {
  margin-top: 0.75rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.stars {
  letter-spacing: 0.08em;
  color: var(--warm);
  font-size: 0.85rem;
  margin-bottom: 0.35rem;
}

/* Pricing */
.price-list {
  display: grid;
  gap: 1.5rem;
}

.price-tier {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem 2rem;
  align-items: start;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--line);
}

.price-tier:first-child {
  border-top: 1px solid var(--line);
}

.price-tier__cost {
  font-family: var(--font-display);
  font-size: 1.8rem;
  color: var(--ink);
  white-space: nowrap;
}

.price-tier ul {
  margin: 0.75rem 0 0;
  padding-left: 1.1rem;
  color: var(--muted);
}

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

/* Forms */
.form {
  display: grid;
  gap: 1.15rem;
  max-width: 36rem;
}

.form-field label {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.9rem;
  color: var(--ink);
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--ink);
}

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

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

.field-error {
  display: block;
  min-height: 1.2em;
  margin-top: 0.3rem;
  font-size: 0.82rem;
  color: var(--danger);
}

.form-status {
  margin-top: 0.5rem;
  font-size: 0.95rem;
}

.form-status--success {
  color: var(--success);
}

.form-status--error {
  color: var(--danger);
}

/* Contact block */
.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
}

@media (max-width: 860px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.address-block {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 1.5rem;
}

.address-block dt {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-top: 1rem;
}

.address-block dt:first-child {
  margin-top: 0;
}

.address-block dd {
  margin: 0.25rem 0 0;
  color: var(--ink);
}

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

.blog-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.5rem;
  align-items: start;
}

.blog-row__media {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--accent-soft);
}

.blog-row__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.prose {
  max-width: 42rem;
}

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

.prose ul,
.prose ol {
  color: var(--muted);
  padding-left: 1.2rem;
}

.prose li {
  margin-bottom: 0.4rem;
}

.article-hero {
  margin-bottom: 2rem;
}

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

/* Page hero compact */
.page-hero {
  padding: 3.5rem 0 2rem;
  border-bottom: 1px solid var(--line);
}

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

.page-hero p {
  max-width: 40rem;
  margin: 0;
}

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

.faq summary {
  cursor: pointer;
  font-weight: 500;
  color: var(--ink);
}

.faq details p {
  margin: 0.75rem 0 0.25rem;
}

/* Modules */
.module-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.module-list li {
  display: grid;
  grid-template-columns: 3.5rem 1fr;
  gap: 1rem;
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line);
}

.module-list span {
  font-family: var(--font-display);
  color: var(--accent);
}

/* Instructor */
.instructor {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.5rem;
  align-items: start;
}

.instructor img {
  width: 140px;
  height: 140px;
  object-fit: cover;
  border-radius: 50%;
}

@media (max-width: 600px) {
  .instructor {
    grid-template-columns: 1fr;
  }
}

/* Table */
.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

th,
td {
  text-align: left;
  padding: 0.75rem 0.85rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  color: var(--ink);
  font-weight: 500;
  background: var(--surface);
}

/* Footer */
.site-footer {
  margin-top: 3rem;
  border-top: 1px solid var(--line);
  background: var(--surface);
  padding: 3rem 0 2rem;
}

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

.site-footer h3 {
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.site-footer p,
.site-footer li {
  color: var(--muted);
  font-size: 0.9rem;
}

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

.site-footer li {
  margin-bottom: 0.4rem;
}

.site-footer a {
  color: var(--muted);
  text-decoration: none;
}

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

.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
}

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

/* Cookie banner */
.cookie-banner {
  position: fixed;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  z-index: 60;
  max-width: 640px;
  margin-inline: auto;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 12px 40px rgba(28, 28, 26, 0.12);
  padding: 1.25rem;
  animation: riseIn 0.45s ease both;
}

.cookie-banner__text {
  margin: 0 0 1rem;
  font-size: 0.9rem;
}

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

/* CTA band */
.cta-band {
  padding: 3.5rem 0;
  background: linear-gradient(135deg, var(--accent) 0%, #2a4142 100%);
  color: #fff;
}

.cta-band h2 {
  color: #fff;
  max-width: 18ch;
}

.cta-band p {
  color: rgba(255, 255, 255, 0.85);
  max-width: 34rem;
}

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

.cta-band .btn--ghost {
  border-color: rgba(255, 255, 255, 0.4);
  color: #fff;
}

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

.case:last-child {
  border-bottom: 0;
}

/* 404 */
.error-page {
  min-height: 60vh;
  display: grid;
  place-content: 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-bottom: 0.5rem;
}

/* Split feature */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

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

@media (max-width: 860px) {
  .split {
    grid-template-columns: 1fr;
  }
}

.legal h2 {
  margin-top: 2.25rem;
}

.legal ul {
  color: var(--muted);
}