/* ========== Base ========== */

:root {
  --bg: #050608;
  --bg-soft: #0b0d10;
  --ink: #f4f4f4;
  --muted: #8b8f96;
  --accent: #e5e2d8;
  --border: #22252a;
  --max-width: 1120px;
  --radius: 10px;
  --gap: 20px;
  --transition: 0.2s ease;
  --font-sans: -apple-system, BlinkMacSystemFont,
    "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic",
    system-ui, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html,
body {
  width: 100%;
  height: 100%;
}

body {
  background: #0d0d0d;
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.wrapper,
.page,
main {
  background: #0d0d0d !important;
}

/* ========== Header ========== */

header {
  padding: 14px 26px 10px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 20px;
  backdrop-filter: blur(10px);
  background: radial-gradient(circle at top, rgba(10, 12, 18, 0.96), rgba(5, 6, 8, 0.96));
  position: sticky;
  top: 0;
  z-index: 20;
}

.site-title a {
  font-size: 17px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.site-subtitle {
  margin-top: 2px;
  font-size: 10px;
  color: var(--muted);
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 11px;
}

nav a {
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

nav a.active {
  border-color: var(--accent);
}

/* ========== Layout ========== */

main {
  flex: 1;
  padding: 28px 26px 40px;
  display: flex;
  justify-content: center;
}

.page {
  width: 100%;
  max-width: var(--max-width);
}

/* ========== Landing ========== */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.9fr) minmax(260px, 1.1fr);
  gap: 22px;
  align-items: flex-end;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 30px;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.hero-subtitle {
  font-size: 13px;
  color: var(--muted);
  max-width: 520px;
}

.hero-keywords {
  margin-top: 14px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.hero-note {
  font-size: 11px;
  color: var(--muted);
  margin-top: 12px;
}

.hero-images {
  margin-bottom: 26px;
  display: grid;
  grid-template-columns: 1.6fr 1.4fr;
  gap: 8px;
}

.hero-image {
  position: relative;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #111;
}

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

.hero-image-label {
  position: absolute;
  left: 10px;
  bottom: 8px;
  font-size: 9px;
  padding: 2px 7px;
  border-radius: 999px;
  background: rgba(3, 4, 6, 0.86);
  color: var(--muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.intro-text {
  max-width: 720px;
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 22px;
}

.chapters-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chapters-links a {
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  transition:
    background var(--transition),
    color var(--transition),
    border-color var(--transition),
    transform var(--transition);
}

.chapters-links a span {
  font-size: 9px;
  color: var(--muted);
  text-transform: none;
  letter-spacing: 0;
  margin-left: 6px;
}

.chapters-links a:hover {
  background: var(--accent);
  color: #050608;
  border-color: var(--accent);
  text-decoration: none;
  transform: translateY(-1px);
}

/* ========== Chapter (sequence view) ========== */

.chapter-header {
  margin-bottom: 22px;
}

.chapter-label {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--muted);
}

.chapter-title {
  font-size: 22px;
  margin: 4px 0 6px;
  font-weight: 400;
  letter-spacing: 0.02em;
}

.chapter-description {
  font-size: 13px;
  color: var(--accent);
  max-width: 720px;
}

/* Document-style sequence for each chapter */
.doc-sequence {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 26px;
}

.doc-item {
  margin: 0;
  padding: 6px;
  border-radius: 6px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
}

.doc-item img {
  width: 100%;
  display: block;
  border-radius: 3px;
  object-fit: cover;
}

.doc-caption {
  margin-top: 3px;
  font-size: 8px;
  color: var(--muted);
  text-align: right;
}

/* installation views: full width break */

.doc-item.installation {
  grid-column: 1 / -1;      /* 그리드 전체 폭 사용 */
  padding: 8px 10px;
  border-style: dashed;
  border-color: #353841;
  background: #050608;
}

.doc-item.installation img {
  border-radius: 4px;
}

.doc-item.installation .doc-caption {
  color: var(--accent);
  font-size: 9px;
}
/* ========== Texts ========== */

.texts-list article {
  padding: 14px 0;
  border-top: 1px solid var(--border);
}

.texts-list article:last-child {
  border-bottom: 1px solid var(--border);
}

.texts-list .label {
  font-size: 9px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

.texts-list h2 {
  font-size: 15px;
  margin: 3px 0 4px;
  font-weight: 400;
}

.texts-list p {
  font-size: 12px;
  color: var(--accent);
  margin: 0;
}

/* ========== About ========== */

.about-section {
  max-width: 720px;
  font-size: 12px;
  color: var(--accent);
}

.about-section h2 {
  font-size: 15px;
  margin: 0 0 6px;
  font-weight: 400;
}

/* ========== Footer ========== */

footer {
  border-top: 1px solid var(--border);
  padding: 8px 26px 12px;
  font-size: 9px;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  gap: 10px;
}

/* ========== Responsive ========== */

@media (max-width: 768px) {
  header {
    position: static;
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 16px 8px;
  }

  main {
    padding: 20px 16px 26px;
  }

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

  .hero-title {
    font-size: 24px;
  }

  .hero-images {
    grid-template-columns: 1fr;
  }
}
.text-block {
  max-width: 720px;
  margin: 80px auto;
  line-height: 1.7;
  font-size: 1.05rem;
  text-align: left;
}

.hidden-gallery {
  display: none;
}