/* =============================================
   TIMELINE.CSS — Chapter 3: Our Story
   ============================================= */
:root {
  --rose:        #c0143c;
  --rose-mid:    #e0365a;
  --rose-light:  #f48fb1;
  --white:       #ffffff;
  --bg:          #04000a;
  --font-display: 'Cinzel', serif;
  --font-serif:   'Cormorant Garamond', serif;
  --font-sans:    'Lato', sans-serif;
  --ease-expo:    cubic-bezier(0.16, 1, 0.3, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--white);
  font-family: var(--font-sans);
  overflow-x: hidden;
  /* Ensure body is tall enough to scroll */
  min-height: 100%;
}

/* ── Background canvas (fixed) ── */
#bg-canvas {
  position: fixed;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 0;
}

/* ── Sticky chapter header ── */
.chapter-header {
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 1.4rem 0 1rem;
  text-align: center;
  background: linear-gradient(to bottom, rgba(4,0,10,0.96) 65%, transparent);
  pointer-events: none;
}
.ch-eyebrow {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.58rem;
  font-weight: 300;
  letter-spacing: 0.45em;
  text-transform: uppercase;
  color: var(--rose-mid);
  margin-bottom: 0.4rem;
}
.ch-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  font-weight: 300;
  letter-spacing: 0.12em;
  color: var(--white);
  text-shadow: 0 0 60px rgba(192,20,60,0.4);
}

/* ── Scroll container ── */
#scroll-container {
  position: relative;   /* essential: spine + flight-path are absolute children */
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.5rem 12vh;
}

/* ── Paper airplane (fixed, JS positions it) ── */
#airplane-wrap {
  position: fixed;
  top: 0; left: 0;
  width: 52px; height: 52px;
  z-index: 30;
  pointer-events: none;
  transform: translate(-50%, -50%);
  filter: drop-shadow(0 0 8px rgba(192,20,60,0.65));
  transition: opacity 0.4s;
}
#airplane { width: 100%; height: 100%; }

/* ── Flight path SVG (absolute inside #scroll-container) ── */
#flight-path {
  position: absolute;
  top: 0; left: 0;
  pointer-events: none;
  z-index: 2;
  overflow: visible;
}

/* ── Spine (absolute inside #scroll-container) ── */
#spine-wrap {
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;           /* full height — button is now outside this container */
  transform: translateX(-50%);
  width: 2px;
  pointer-events: none;
  z-index: 2;
}
#spine-track {
  position: relative;
  width: 100%; height: 100%;
  background: rgba(192,20,60,0.08);
  border-radius: 1px;
}
#spine-fill {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 0%;
  background: linear-gradient(to bottom, var(--rose-mid), var(--rose-light));
  border-radius: 1px;
  transition: height 0.06s linear;
  box-shadow: 0 0 12px rgba(192,20,60,0.5);
}

/* ── Events wrapper ── */
#events-wrap {
  position: relative;
  z-index: 5;
  padding: 6vh 0 4vh;
}

/* ── Individual event ── */
.tl-event {
  position: relative;
  display: flex;
  align-items: center;
  margin-bottom: 13vh;
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.75s var(--ease-expo), transform 0.75s var(--ease-expo);
}
.tl-event.visible { opacity: 1; transform: translateY(0); }

.tl-event.left  { flex-direction: row; }
.tl-event.right { flex-direction: row-reverse; }

/* Centre dot */
.tl-dot {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--rose-mid);
  border: 2px solid rgba(255,255,255,0.12);
  box-shadow: 0 0 16px rgba(192,20,60,0.7), 0 0 4px rgba(255,255,255,0.3);
  z-index: 10;
  flex-shrink: 0;
  transition: transform 0.4s var(--ease-expo), box-shadow 0.4s;
}
.tl-event.visible .tl-dot {
  transform: translateX(-50%) scale(1.25);
  box-shadow: 0 0 26px rgba(192,20,60,0.95), 0 0 6px rgba(255,255,255,0.4);
}

/* Card */
.tl-card {
  width: calc(50% - 2.8rem);
  padding: 1.5rem 1.8rem;
  background: rgba(255,255,255,0.025);
  border: 1px solid rgba(192,20,60,0.16);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
}
.tl-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(192,20,60,0.5), transparent);
}
.tl-event.left  .tl-card { margin-right: auto; text-align: right; }
.tl-event.right .tl-card { margin-left:  auto; text-align: left;  }

.tl-date {
  font-family: var(--font-sans);
  font-size: 0.58rem;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--rose-mid);
  margin-bottom: 0.5rem;
}
.tl-title {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.2vw, 1.45rem);
  font-weight: 300;
  letter-spacing: 0.06em;
  color: var(--white);
  margin-bottom: 0.6rem;
}
.tl-desc {
  font-family: var(--font-serif);
  font-size: clamp(0.9rem, 1.5vw, 1.05rem);
  font-style: italic;
  color: rgba(255,255,255,0.5);
  line-height: 1.7;
}
.tl-icon {
  position: absolute;
  font-size: 1.8rem;
  opacity: 0.12;
  pointer-events: none;
}
.tl-event.left  .tl-icon { bottom: 0.6rem; left: 0.8rem; }
.tl-event.right .tl-icon { bottom: 0.6rem; right: 0.8rem; }

/* Spotify */
.tl-spotify { margin-top: 1rem; border-radius: 4px; overflow: hidden; }

/* ── Chapter nav buttons (outside scroll-container) ── */
#chapter-nav {
  display: flex;
  justify-content: center;
  gap: 1rem;
  padding: 4vh 1.5rem 8vh;
  position: relative;
  z-index: 10;
}

/* Hero-identical button — matches flower/hero */
.ch-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1.8rem;
  font-family: var(--font-sans);
  font-size: 0.65rem;
  font-weight: 300;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--white);
  border: 1px solid rgba(255,255,255,0.18);
  position: relative;
  overflow: hidden;
  transition: border-color 0.4s;
}
.ch-btn::before {
  content: '';
  position: absolute; inset: 0;
  background: var(--rose);
  transform: translateX(-101%);
  transition: transform 0.5s var(--ease-expo);
}
.ch-btn:hover::before { transform: translateX(0); }
.ch-btn:hover { border-color: var(--rose); }
.ch-btn span, .ch-btn svg { position: relative; z-index: 1; }
.ch-btn:hover svg { transition: transform 0.4s; }

.ch-btn--next {
  border-color: rgba(192,20,60,0.35);
}

/* ── Keyframes ── */
@keyframes fadeIn { to { opacity: 1; } }

/* ================================================================
   MOBILE  ≤700px
   Spine shifts to left edge; all cards full width on the right
   ================================================================ */
@media (max-width: 700px) {
  #scroll-container { padding: 0 1rem 4vh; }

  /* Spine: left rail, full height of scroll-container (buttons are outside) */
  #spine-wrap {
    left: 1.5rem;
    transform: none;
    bottom: 0;
  }

  /* All events: single column on the right */
  .tl-event,
  .tl-event.left,
  .tl-event.right {
    flex-direction: row !important;
    margin-bottom: 7vh;
    padding-left: 3.4rem;
  }

  /* Dot anchored to the spine */
  .tl-event .tl-dot,
  .tl-event.left .tl-dot,
  .tl-event.right .tl-dot {
    left: 1.5rem !important;
    right: auto !important;
    transform: translateX(-50%) !important;
  }
  .tl-event.visible .tl-dot,
  .tl-event.left.visible .tl-dot,
  .tl-event.right.visible .tl-dot {
    transform: translateX(-50%) scale(1.25) !important;
  }

  /* Cards: full width, left-aligned */
  .tl-card,
  .tl-event.left  .tl-card,
  .tl-event.right .tl-card {
    width: 100% !important;
    margin: 0 !important;
    text-align: left !important;
  }
  .tl-icon { display: none; }

  #events-wrap { padding-top: 3vh; }

  /* Airplane: visible, JS positions it */
  #airplane-wrap {
    display: block;
    width: 36px;
    height: 36px;
    position: fixed;
    opacity: 1;
  }
  #flight-path { display: none; }

  /* Nav buttons: stacked, full width */
  #chapter-nav {
    flex-direction: column;
    align-items: center;
    gap: 0.7rem;
    padding: 3vh 1rem 6vh;
  }
  .ch-btn {
    width: 88vw;
    justify-content: center;
  }
}