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

:root {
  --black: #090e0a;
  --white: #e4ede6;
  --red: #6dbd7a;
  --border: #131e14;
  --faint: #111a12;
  --muted: #3a5040;
}

html { scroll-behavior: smooth; }

body {
  background: #000000;
  color: var(--white);
  font-family: 'Space Mono', monospace;
  overflow-x: hidden;
}

/* LAYOUT */
.page-wrap {
  max-width: 1280px;
  margin: 0 auto;
  background: var(--black);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}

/* HERO */
.book-hero {
  padding-top: 60px;
  min-height: 100vh;
  display: grid;
  grid-template-columns: 480px 1fr;
  border-bottom: 1px solid var(--border);
}

.book-cover-col {
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
}

.book-cover-wrap {
  flex: 1;
  padding: 4rem 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--faint);
  position: relative;
  overflow: hidden;
}

.book-cover-wrap::before {
  content: 'UNDERXGRIND';
  position: absolute;
  font-family: 'Bebas Neue', sans-serif;
  font-size: 8rem;
  color: var(--red);
  opacity: 0.03;
  letter-spacing: 0.1em;
  transform: rotate(-15deg);
  white-space: nowrap;
  pointer-events: none;
}

.book-cover-img {
  width: 240px;
  box-shadow: 0 40px 80px rgba(0,0,0,0.6), 0 0 0 1px rgba(109,189,122,0.1);
  position: relative;
  z-index: 1;
  transition: transform 0.4s ease;
}
.book-cover-img:hover { transform: translateY(-6px) rotate(-1deg); }

.book-cover-meta {
  padding: 1.5rem 3rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.book-num-badge {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 0.92rem;
  letter-spacing: 0.2em;
  color: #2a4030;
}

.book-genre-tag {
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  border: 1px solid #1e3020;
  padding: 0.3rem 0.7rem;
  color: var(--red);
}

/* BOOK INFO */
.book-info-col {
  display: flex;
  flex-direction: column;
}

.book-info-main {
  flex: 1;
  padding: 5rem 4rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.book-eyebrow {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.book-eyebrow-line { width: 28px; height: 1px; background: var(--red); }
.book-eyebrow-text { font-size: 0.66rem; letter-spacing: 0.3em; text-transform: uppercase; color: var(--red); }

.book-title-main {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: clamp(2.2rem, 4vw, 3.5rem);
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--white);
  margin-bottom: 1.2rem;
}

.book-author-line {
  font-size: 0.82rem;
  letter-spacing: 0.15em;
  color: #5a7060;
  margin-bottom: 3rem;
  font-family: 'Noto Sans KR', sans-serif;
}

.book-desc {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.92rem;
  line-height: 2.2;
  color: #6a8070;
  max-width: 520px;
  letter-spacing: 0.02em;
  margin-bottom: 3rem;
}

.book-cta-group {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--black);
  background: var(--red);
  border: 1px solid var(--red);
  text-decoration: none;
  padding: 0.85rem 2rem;
  transition: all 0.2s;
  font-family: 'Space Mono', monospace;
}
.btn-primary:hover { background: transparent; color: var(--red); }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--white);
  border: 1px solid #1e3020;
  text-decoration: none;
  padding: 0.85rem 2rem;
  transition: all 0.2s;
  font-family: 'Space Mono', monospace;
}
.btn-secondary:hover { border-color: var(--white); }

/* SPECS STRIP */
.book-specs {
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.spec-item {
  padding: 1.5rem 2rem;
  border-right: 1px solid var(--border);
}
.spec-item:last-child { border-right: none; }

.spec-label {
  font-size: 0.58rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: #2a4030;
  margin-bottom: 0.5rem;
}

.spec-value {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 1.2rem;
  letter-spacing: 0.05em;
  color: var(--white);
  line-height: 1.1;
}

.spec-sub {
  font-size: 0.62rem;
  color: #4a6050;
  margin-top: 0.3rem;
  letter-spacing: 0.08em;
}

/* CONTENT SECTIONS */
.content-section {
  display: grid;
  grid-template-columns: 240px 1fr;
  border-bottom: 1px solid var(--border);
  min-height: 30vh;
}

.content-label-col {
  padding: 3rem 2.5rem;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.content-section-num {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 4rem;
  line-height: 1;
  color: #111a12;
}

.content-section-title {
  font-size: 0.66rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--red);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  align-self: flex-end;
}

.content-body-col {
  padding: 3rem 4rem;
}

/* SYNOPSIS */
.synopsis-text {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.94rem;
  line-height: 2.4;
  color: #6a8070;
  letter-spacing: 0.02em;
  max-width: 640px;
}

.synopsis-text p + p { margin-top: 1.5rem; }

.synopsis-pull {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 2rem;
  line-height: 1.1;
  letter-spacing: 0.03em;
  color: var(--white);
  margin: 2.5rem 0;
  max-width: 480px;
  padding-left: 1.5rem;
  border-left: 3px solid var(--red);
}

/* TABLE OF CONTENTS */
.toc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}

.toc-chapter {
  padding: 1.2rem 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  gap: 1.2rem;
}
.toc-chapter:nth-child(odd) { padding-right: 2rem; border-right: 1px solid var(--border); }
.toc-chapter:nth-child(even) { padding-left: 2rem; }
.toc-chapter:nth-last-child(-n+2) { border-bottom: none; }

.toc-num {
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  color: var(--red);
  flex-shrink: 0;
  font-family: 'Space Mono', monospace;
}

.toc-title {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.88rem;
  color: #8aaa90;
  letter-spacing: 0.02em;
  line-height: 1.5;
}

/* AUTHOR */
.author-block {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.author-name {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 2.5rem;
  letter-spacing: 0.05em;
  color: var(--white);
}

.author-bio {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.90rem;
  line-height: 2.2;
  color: #6a8070;
  max-width: 560px;
  letter-spacing: 0.02em;
}

/* REVIEWS */
.reviews-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}

.review-item {
  padding: 2rem;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.review-item:nth-child(even) { border-right: none; }
.review-item:nth-last-child(-n+2) { border-bottom: none; }

.review-stars {
  font-size: 0.72rem;
  color: var(--red);
  letter-spacing: 0.2em;
  margin-bottom: 0.8rem;
}

.review-text {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.88rem;
  line-height: 2;
  color: #6a8070;
  letter-spacing: 0.02em;
  margin-bottom: 1rem;
}

.review-from {
  font-size: 0.64rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #2a4030;
}

/* BUY SECTION */
.buy-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-bottom: 1px solid var(--border);
}

.buy-left {
  padding: 4rem;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.5rem;
}

.buy-price-label {
  font-size: 0.64rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: #2a4030;
}

.buy-price {
  font-family: 'Bebas Neue', sans-serif;
  font-size: 4rem;
  letter-spacing: 0.03em;
  line-height: 1;
  color: var(--white);
}

.buy-price-note {
  font-size: 0.66rem;
  color: #4a6050;
  letter-spacing: 0.1em;
  margin-top: 0.3rem;
}

.buy-right {
  padding: 4rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1rem;
}

.buy-desc {
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.75rem;
  line-height: 2;
  color: #4a6050;
  letter-spacing: 0.02em;
  margin-bottom: 1rem;
}

.top-btn {
  position: fixed;
  right: calc((100vw - 1280px) / 2 - 52px);
  bottom: 2.5rem;
  width: 42px;
  background: transparent;
  border: 1px solid #1e3020;
  color: #4a6050;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 0.9rem 0;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.3s, transform 0.3s, border-color 0.2s, color 0.2s;
  pointer-events: none;
  z-index: 300;
}
.top-btn.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.top-btn:hover {
  border-color: #6dbd7a;
  color: #6dbd7a;
}
.top-btn-line {
  display: block;
  width: 1px;
  height: 28px;
  background: currentColor;
}
.top-btn-text {
  font-family: 'Space Mono', monospace;
  font-size: 0.56rem;
  letter-spacing: 0.2em;
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}
@media (max-width: 1380px) {
  .top-btn { right: 0.8rem; }
}

@media (max-width: 980px) {
  .page-wrap {
    border-left: none;
    border-right: none;
    overflow-x: hidden;
  }

  .book-hero,
  .content-section,
  .buy-section {
    grid-template-columns: minmax(0, 1fr);
  }

  .book-hero {
    padding-top: 52px;
    min-height: auto;
  }

  .book-cover-col {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .book-cover-wrap {
    padding: 2.5rem 1.5rem;
  }

  .book-cover-img {
    width: min(210px, 62vw);
  }

  .book-cover-meta {
    padding: 1.2rem 1.5rem;
  }

  .book-info-main {
    padding: 3rem 1.5rem;
  }

  .book-title-main {
    font-size: clamp(2rem, 10vw, 3rem);
  }

  .book-specs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .spec-item {
    padding: 1.2rem 1.5rem;
  }

  .content-label-col {
    padding: 1.5rem;
    border-right: none;
    border-bottom: 1px solid var(--border);
    gap: 1rem;
  }

  .content-section-title {
    writing-mode: horizontal-tb;
    transform: none;
    align-self: flex-start;
  }

  .content-body-col,
  .buy-left,
  .buy-right {
    padding: 2rem 1.5rem;
  }

  .toc-grid,
  .reviews-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .toc-chapter:nth-child(odd),
  .toc-chapter:nth-child(even),
  .review-item {
    padding-left: 0;
    padding-right: 0;
    border-right: none;
  }

  .toc-chapter:nth-last-child(-n+2),
  .review-item:nth-last-child(-n+2) {
    border-bottom: 1px solid var(--border);
  }

  .buy-left {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    justify-content: center;
    padding-left: 1rem;
    padding-right: 1rem;
  }
}