@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=IBM+Plex+Sans:wght@300;400;500&display=swap');

/* tokens */
:root {
  --color-surface-primary: #E8E1D9;
  --color-surface-secondary: #D3EEFF;
  --color-surface-dark: #243743;
  --color-text-primary: #3A2F2A;
  --color-text-inverse: #E8F3ED;
  --color-text-accent: #2F4F3A;
  --color-accent-warm: #F3D6D0;
  --color-accent-gold: #DEC978;
  --font-heading: "DM Serif Display", serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --text-h1: clamp(3rem, 6vw, 4rem);
  --text-h2: clamp(2rem, 4vw, 2.5rem);
  --text-h3: 1.375rem;
  --text-body: 1.125rem;
  --text-label: 2.5rem;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --transition-default: 200ms ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  font-size: var(--text-body);
  color: var(--color-text-primary);
  background-color: var(--color-surface-primary);
}

/* =========================
   chapter frames layout
========================== */
.chapter {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1fr 1fr;
  position: relative;
  overflow: hidden;
}

/* sky/soil horizon split at 55% */
.chapter::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    var(--color-surface-secondary) 55%,
    var(--color-surface-primary) 55%
  );
  z-index: 0;
}

.chapter--dark::before {
  background: linear-gradient(
    to bottom,
    var(--color-surface-dark) 55%,
    var(--color-surface-primary) 55%
  );
}

/* left side text */
.chapter-text {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--space-xl) var(--space-lg);
  gap: var(--space-sm);
}

.chapter-label {
  font-family: var(--font-heading);
  font-size: var(--text-h3);
  color: var(--color-text-primary);
  opacity: 0.5;
  font-style: italic;
}

.chapter-heading {
  font-family: var(--font-heading);
  font-size: var(--text-h2);
  line-height: 1.15;
  color: var(--color-text-primary);
}

.chapter-heading em {
  font-style: italic;
  color: var(--color-text-accent);
}

.chapter--dark .chapter-label,
.chapter--dark .chapter-heading {
  color: var(--color-text-inverse);
}

.chapter-body {
  font-family: var(--font-body);
  font-size: var(--text-body);
  font-weight: 300;
  line-height: 1.75;
  color: var(--color-text-primary);
  max-width: 36ch;
}

.chapter-note {
  font-size: 0.8rem;
  color: var(--color-text-primary);
  opacity: 0.4;
  font-style: italic;
  margin-top: var(--space-xs);
}

/* visual stuff */
.chapter-visual {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chapter-visual img {
  max-width: 80%;
  max-height: 80vh;
  object-fit: contain;
}

/* ch1 */
#ch1 .chapter-visual img[alt="A seed packet"] {
  position: absolute;
  width: 40%;
  left: 10%;
  top: 15%;
  transform: rotate(14deg);
  transform-origin: top left;
}

#ch1 .chapter-visual img[alt="seeds"] {
  position: absolute;
  width: 9%;
  left: 14%;
  top: 44%;
}

/* =========================
   ch2
========================== */
#ch2 .ch2-roots,
#ch2 .ch2-sprout,
#ch2 .drops {
  position: absolute;
  z-index: 1;
}

#ch2 .ch2-roots {
  width: 33%;
  right: 8%;
  bottom: 0;
}

#ch2 .ch2-roots img,
#ch2 .ch2-sprout img {
  width: 100%;
  display: block;
}

#ch2 .ch2-sprout {
  width: 12%;
  right: 18%;
  bottom: 44%;
}

#ch2 .drops {
  display: flex;
  gap: 2.5%;
  right: 10%;
  top: 8%;
}

#ch2 .drops img {
  width: 42px;
}

#ch2 .drops img:nth-child(1) { margin-top: 0rem; }
#ch2 .drops img:nth-child(2) { margin-top: 3rem; }
#ch2 .drops img:nth-child(3) { margin-top: 1rem; }

/* =========================
   ch3
========================== */
#ch3 .ch3-roots,
#ch3 .ch3-sprout,
#ch3 .ch3-watering-can,
#ch3 .ch3-drop {
  position: absolute;
  z-index: 1;
}

#ch3 .ch3-roots {
  width: 33%;
  right: 8%;
  bottom: 0;
}

#ch3 .ch3-roots img,
#ch3 .ch3-sprout img {
  width: 100%;
  display: block;
}

#ch3 .ch3-sprout {
  width: 12%;
  right: 18%;
  bottom: 44%;
}

#ch3 .ch3-watering-can {
  width: 21%;
  right: 5%;
  top: 10%;
}

#ch3 .ch3-watering-can img {
  width: 100%;
  display: block;
}

/* slightly bigger raindrop, left of can */
#ch3 .ch3-drop {
  width: 4%;
  right: 25%;
  top: 32%;
}

#ch3 .ch3-drop img {
  width: 100%;
  display: block;
}

/* =========================
   ch4
========================== */
#ch4 .chapter-visual img {
  position: absolute;
  width: 33%;
  right: 8%;
  bottom: 0;
}

#ch4 .sprout {
  position: absolute;
  z-index: 1;
  width: 12%;
  right: 18%;
  bottom: 44%;
}

#ch4 .sprout img {
  width: 100%;
  display: block;
}

/* =========================
   ch5
========================== */
#ch5 .chapter-visual img[alt="roots"] {
  position: absolute;
  width: 40%;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
}

#ch5 .chapter-visual img[alt="A flower in full bloom with roots"] {
  position: absolute;
  width: 28%;
  bottom: 42%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
}

/* =========================
   responsive
========================== */
@media (max-width: 768px) {
  .chapter {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .chapter-text {
    padding: var(--space-lg) var(--space-md) var(--space-md);
  }

  .chapter-visual {
    min-height: 320px;
  }

  /* ch1 seed packet */
  #ch1 .chapter-visual img[alt="A seed packet"] {
    position: absolute;
    width: 55%;
    right: 4%;
    top: 8%;
    transform: rotate(-14deg);
    transform-origin: top right;
  }

  #ch1 .chapter-visual img[alt="seeds"] {
    display: none;
  }

  /* ch2 & ch3 stacking */
  #ch2 .ch2-roots,
  #ch3 .ch3-roots {
    position: relative;
    width: 75%;
    right: auto;
    bottom: auto;
    margin: var(--space-md) auto 0;
  }

  #ch2 .ch2-sprout,
  #ch3 .ch3-sprout { display: none; }

  #ch2 .drops {
    position: relative;
    top: auto;
    right: auto;
    justify-content: center;
    padding: var(--space-md) 0 0;
  }

  #ch3 .ch3-watering-can {
    position: relative;
    width: 45%;
    top: auto;
    right: auto;
    margin: var(--space-md) auto 0;
    display: block;
  }

  #ch3 .ch3-drop { display: none; }

  #ch5 .chapter-visual img[alt="roots"],
  #ch5 .chapter-visual img[alt="A flower in full bloom with roots"] {
    position: relative;
    width: 60%;
    bottom: auto;
    left: auto;
    transform: none;
    margin: 0 auto;
    display: block;
  }
}