:root {
  --bg-app: #1e1e1e;
  --bg-panel: #252526;
  --bg-header: #252528;
  --bg-input: #2d2d30;
  --border: #3c3c3c;
  --text: #d4d4d4;
  --text-muted: #8a8a8a;
  --heading: #ececec;
  --accent: #3b9eff;
  --accent-hover: #5aadff;
  --accent-muted: rgba(59, 158, 255, 0.14);
  --header-h: 48px;
  --page-max: 1080px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
  font-size: 16px;
}

body {
  margin: 0;
  font-family: "Segoe UI", "Noto Sans KR", system-ui, sans-serif;
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(59, 158, 255, 0.08), transparent),
    var(--bg-app);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ── App header ── */
.app-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  height: auto;
  padding: 6px 14px;
  background: rgba(37, 37, 40, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  overflow: visible;
}

.app-bar-left {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  flex: 1;
  overflow: visible;
}

.app-bar-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  overflow: visible;
}

.app-bar-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  min-height: 30px;
  padding: 6px 12px;
  line-height: 1.25;
  border-radius: 4px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.15s;
}

.app-bar-cta:hover {
  background: var(--accent-hover);
}

.app-bar-cta-ghost:hover {
  background: rgba(59, 158, 255, 0.12);
  color: #c8e4ff;
}

.app-bar-cta-ghost {
  background: transparent;
  color: #9ecfff;
  border: 1px solid rgba(59, 158, 255, 0.35);
}

.app-icon {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  object-fit: contain;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 24px;
  padding: 3px 8px;
  line-height: 1.25;
  border-radius: 4px;
  background: var(--accent-muted);
  border: 1px solid rgba(59, 158, 255, 0.28);
  color: #9ecfff;
  font-size: 10px;
  font-weight: 600;
  white-space: nowrap;
}

.app-bar-slogan {
  font-size: 11px;
  font-weight: 500;
  line-height: 1.25;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

.app-bar-slogan::before {
  content: "·";
  margin: 0 0.45rem;
  color: rgba(255, 255, 255, 0.2);
  font-weight: 400;
}

/* ── Page ── */
.page {
  width: min(var(--page-max), calc(100% - 3rem));
  margin: 0 auto;
  padding: calc(var(--header-h) + 2rem) 0 3rem;
}

/* ── Hero ── */
.hero {
  margin-bottom: 1.75rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.75rem 2rem;
  align-items: start;
}

.hero-copy {
  max-width: 420px;
}

.hero-title-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.35rem;
}

.hero-icon {
  flex-shrink: 0;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.hero-brand-ko {
  margin: 0 0 0.55rem;
  padding-top: 0;
  line-height: 1.2;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.hero-copy h1 {
  margin: 0;
  font-size: clamp(1.85rem, 3.8vw, 2.45rem);
  font-weight: 600;
  color: #ffffff;
  letter-spacing: -0.02em;
}

.hero-motto {
  margin: 0.55rem 0 0;
  font-size: 1.08rem;
  font-weight: 600;
  color: #9ecfff;
  line-height: 1.45;
}

.hero-tagline {
  margin: 0.4rem 0 0.35rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  letter-spacing: 0.03em;
}

.hero-audience {
  margin: 0 0 1rem;
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--text-muted);
}

.hero-audience strong {
  color: #9ecfff;
  font-weight: 600;
}

.hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.hero-chips li {
  padding: 5px 11px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 500;
  color: #c8e4ff;
  background: rgba(59, 158, 255, 0.12);
  border: 1px solid rgba(59, 158, 255, 0.25);
}

.hero-preview-wrap {
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.hero-preview {
  margin: 0;
  width: 100%;
  max-width: 400px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid rgba(59, 158, 255, 0.12);
  background: linear-gradient(145deg, #1e1e24, #141418);
  box-shadow:
    0 16px 48px rgba(0, 0, 0, 0.55),
    0 0 64px rgba(39, 109, 195, 0.1),
    0 0 0 1px rgba(255, 255, 255, 0.06) inset;
  line-height: 0;
  aspect-ratio: 795 / 400;
}

.hero-preview img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
}

/* ── Highlights ── */
.highlights {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.highlight-card {
  padding: 1rem 1.1rem;
  border-radius: 5px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  transition: border-color 0.15s;
}

.highlight-card:hover {
  border-color: rgba(59, 158, 255, 0.35);
}

.highlight-icon {
  display: block;
  font-size: 1.35rem;
  margin-bottom: 0.35rem;
}

.highlight-card h3 {
  margin: 0 0 0.2rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--heading);
}

.highlight-card p {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.45;
}

/* ── Content grid ── */
.content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1.75rem 2rem;
}

.card-eyebrow {
  margin: 0 0 0.4rem;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.card h2 {
  margin: 0 0 0.85rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--heading);
}

.lead {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  line-height: 1.75;
}

.lead strong {
  color: #9ecfff;
  font-weight: 600;
}

.intro-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.intro-list li {
  position: relative;
  padding: 0.45rem 0 0.45rem 1.1rem;
  font-size: 0.86rem;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.intro-list li:first-child {
  border-top: none;
  padding-top: 0;
}

.intro-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

.intro-list strong {
  color: var(--text);
}

.download-version {
  margin: 0 0 0.75rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.download-version span {
  color: var(--heading);
  font-weight: 500;
}

.download-recommend {
  margin: 0 0 1rem;
  font-size: 0.86rem;
  line-height: 1.6;
  color: #9ecfff;
}

.download-recommend strong {
  color: #c8e4ff;
}

.btn-full {
  display: flex;
  width: 100%;
  margin-bottom: 0.25rem;
}

.btn-zip {
  background: #0d7a4a;
  color: #ecfdf5;
  border: 1px solid #10b981;
}

.btn-zip:hover {
  background: #0f9660;
}

.btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
  padding: 1rem 0.75rem;
  border-radius: 5px;
  text-decoration: none;
  font-size: 13px;
  transition: background 0.15s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-label {
  font-weight: 600;
}

.btn-meta {
  display: block;
  font-size: 11px;
  opacity: 0.85;
}

.install-help {
  margin: 1rem 0 0;
  border: 1px solid rgba(59, 158, 255, 0.22);
  border-radius: 5px;
  background: rgba(59, 158, 255, 0.05);
}

.install-help summary {
  padding: 0.65rem 1rem;
  font-size: 0.84rem;
  font-weight: 600;
  color: #9ecfff;
  cursor: pointer;
  list-style: none;
}

.install-help summary::-webkit-details-marker {
  display: none;
}

.install-help-body {
  padding: 0 1rem 0.85rem;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text-muted);
}

.install-help-body ol {
  margin: 0;
  padding-left: 1.2rem;
}

.install-steps li {
  margin-bottom: 0.45rem;
}

.install-steps strong {
  color: var(--text);
}

.install-help-note {
  margin: 0.5rem 0 0;
  padding: 0.5rem 0.6rem;
  border-radius: 4px;
  background: rgba(59, 158, 255, 0.08);
  border: 1px solid rgba(59, 158, 255, 0.2);
  font-size: 0.78rem;
  color: #9ecfff;
}

/* ── Feature tiles ── */
.feature-tiles {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}

.feature-tile {
  padding: 1.15rem 1rem;
  border-radius: 5px;
  background: var(--bg-input);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.feature-tile-icon {
  display: block;
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.feature-tile h3 {
  margin: 0 0 0.35rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--heading);
}

.feature-tile p {
  margin: 0;
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--text-muted);
}

/* ── Edition compare ── */
.edition-compare {
  margin-bottom: 1.25rem;
}

.edition-lead {
  margin: 0 0 1.1rem;
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--text-muted);
}

.edition-lead strong {
  color: #9ecfff;
  font-weight: 600;
}

.edition-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.edition-col {
  padding: 1rem 1.15rem;
  border-radius: 5px;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.15);
}

.edition-col-beta {
  border-color: rgba(59, 158, 255, 0.25);
}

.edition-col-formal {
  border-color: rgba(255, 200, 80, 0.22);
}

.edition-col h3 {
  margin: 0 0 0.75rem;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--heading);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.edition-tag {
  font-size: 0.68rem;
  font-weight: 500;
  padding: 0.15rem 0.45rem;
  border-radius: 3px;
  background: rgba(59, 158, 255, 0.15);
  color: #9ecfff;
  border: 1px solid rgba(59, 158, 255, 0.3);
}

.edition-tag-formal {
  background: rgba(255, 200, 80, 0.12);
  color: #ffe8a3;
  border-color: rgba(255, 200, 80, 0.35);
}

.edition-dl {
  margin: 0;
}

.edition-dl > div {
  padding: 0.55rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.edition-dl > div:first-child {
  border-top: none;
  padding-top: 0;
}

.edition-dl dt {
  margin: 0 0 0.2rem;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.edition-dl dd {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.55;
  color: var(--text);
}

.edition-note {
  color: var(--text-muted);
  font-size: 0.78rem;
}

.edition-foot {
  margin: 1rem 0 0;
  font-size: 0.8rem;
  line-height: 1.55;
  color: var(--text-muted);
}

.edition-foot a {
  color: #9ecfff;
  text-decoration: none;
}

.edition-foot a:hover {
  text-decoration: underline;
}

/* ── Workshop ── */
.workshop {
  margin-bottom: 1.25rem;
  background:
    linear-gradient(135deg, rgba(13, 122, 74, 0.08) 0%, var(--bg-panel) 45%),
    var(--bg-panel);
  border-color: rgba(16, 185, 129, 0.22);
}

.workshop-lead {
  margin: 0 0 1rem;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--text-muted);
}

.workshop-lead a {
  color: #9ecfff;
  text-decoration: none;
}

.workshop-lead a:hover {
  text-decoration: underline;
}

.workshop-lead strong {
  color: #a7f3d0;
  font-weight: 600;
}

.workshop-price {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.45rem 0.75rem;
  margin-bottom: 1rem;
  padding: 0.85rem 1rem;
  border-radius: 5px;
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.22);
}

.workshop-price-label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.workshop-price-value {
  font-size: 1.05rem;
  color: #ecfdf5;
}

.workshop-price-value strong {
  color: #6ee7b7;
  font-weight: 700;
}

.workshop-price-note {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.workshop-sessions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.workshop-session {
  padding: 1rem 1.1rem;
  border-radius: 5px;
  border: 1px solid rgba(16, 185, 129, 0.2);
  background: rgba(0, 0, 0, 0.15);
}

.workshop-session-label {
  margin: 0 0 0.25rem;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #6ee7b7;
}

.workshop-session h3 {
  margin: 0 0 0.35rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--heading);
}

.workshop-session-meta {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.workshop-session-meta strong {
  color: #a7f3d0;
}

.workshop-list {
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
}

.workshop-list li {
  position: relative;
  padding: 0.4rem 0 0.4rem 1.1rem;
  font-size: 0.84rem;
  line-height: 1.55;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.workshop-list li:first-child {
  border-top: none;
  padding-top: 0;
}

.workshop-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #10b981;
}

.workshop-list strong {
  color: #c8e4ff;
  font-weight: 600;
}

.btn-workshop {
  background: #0d7a4a;
  color: #ecfdf5;
  border: 1px solid #10b981;
}

.btn-workshop:hover {
  background: #0f9660;
}

.workshop-note {
  margin: 0.75rem 0 0;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.workshop-note a {
  color: #9ecfff;
  text-decoration: none;
}

.workshop-note a:hover {
  text-decoration: underline;
}

/* ── Inquiry ── */
.inquiry {
  margin-bottom: 1.25rem;
  background:
    linear-gradient(135deg, rgba(180, 120, 20, 0.06) 0%, var(--bg-panel) 40%),
    var(--bg-panel);
  border-color: rgba(255, 200, 80, 0.2);
}

.inquiry-teaser {
  margin: 0 0 1.25rem;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-muted);
}

.inquiry-teaser strong {
  color: #ffe8a3;
  font-weight: 600;
}

.inquiry-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.inquiry-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0.85rem 0.75rem;
  border-radius: 5px;
  font-size: 13px;
  font-weight: 600;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.15s, filter 0.15s;
}

.inquiry-btn-purchase {
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  color: #eff6ff;
  border: 1px solid #3b82f6;
}

.inquiry-btn-purchase:hover {
  filter: brightness(1.08);
}

.inquiry-btn-lecture {
  background: linear-gradient(135deg, rgba(140, 90, 15, 0.85), rgba(100, 60, 10, 0.9));
  color: #ffe8a3;
  border: 1px solid rgba(255, 200, 80, 0.45);
}

.inquiry-btn-lecture:hover {
  filter: brightness(1.1);
}

/* ── Footer ── */
.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-brand img {
  border-radius: 50%;
  opacity: 0.9;
}

.footer-copy {
  margin: 0;
}

.footer-inquiry {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.footer-inquiry:hover {
  color: #ffe8a3;
  border-bottom-color: rgba(255, 200, 80, 0.4);
}

@media (max-width: 960px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    max-width: none;
    text-align: center;
  }

  .hero-title-row {
    justify-content: center;
  }

  .hero-chips {
    justify-content: center;
  }

  .hero-preview {
    order: -1;
    max-width: min(100%, 440px);
    margin-inline: auto;
  }

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

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

@media (max-width: 860px) {
  .app-bar-slogan {
    display: none;
  }

  .app-bar-cta-ghost {
    padding: 6px 10px;
    font-size: 11px;
  }

  .app-bar-cta {
    padding: 6px 10px;
    font-size: 11px;
  }

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

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

  .workshop-sessions {
    grid-template-columns: 1fr;
  }

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

  .footer-brand {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .page {
    width: calc(100% - 2rem);
  }

  .hero-title-row {
    flex-direction: column;
    text-align: center;
  }

  .hero-chips {
    justify-content: center;
  }

  .highlights,
  .feature-tiles,
  .inquiry-actions {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 1.35rem 1.15rem;
  }
}