:root {
  --ink: #23332e;
  --forest: #52685c;
  --sage: #879487;
  --cream: #f7f3eb;
  --paper: #fffdf8;
  --line: rgba(63, 76, 69, .24);
  --shadow: 0 28px 65px rgba(40, 49, 45, .22);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 16% 10%, rgba(135, 148, 135, .18), transparent 27rem),
    linear-gradient(145deg, #fbf9f4, #ebe8e1);
  font-family: Avenir, "Helvetica Neue", Arial, sans-serif;
}

button, a { font: inherit; }

.page-shell {
  width: min(1500px, 100%);
  margin: 0 auto;
  padding: clamp(28px, 5vw, 68px) clamp(18px, 4vw, 56px) 48px;
}

.intro { text-align: center; margin: 0 auto 22px; max-width: 760px; }
.eyebrow { margin: 0 0 8px; color: var(--forest); font-size: .78rem; font-weight: 700; letter-spacing: .24em; }
.intro h1 { margin: 0; font-family: Georgia, "Times New Roman", serif; font-size: clamp(2rem, 4vw, 3.8rem); font-weight: 400; letter-spacing: -.035em; }
.intro > p:last-child { margin: 12px auto 0; max-width: 640px; color: #53615b; font-size: clamp(1rem, 1.7vw, 1.15rem); line-height: 1.55; }

.brochure-section { display: grid; justify-items: center; }
.stage {
  width: 100%;
  height: min(74vw, 1080px);
  min-height: 450px;
  display: grid;
  place-items: center;
  perspective: 2200px;
  overflow: hidden;
}

.brochure {
  --full-w: min(88vw, 1320px);
  --panel-w: calc(var(--full-w) / 3);
  --panel-h: calc(var(--full-w) * .768);
  position: relative;
  width: var(--full-w);
  height: var(--panel-h);
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  transform-style: preserve-3d;
  outline: none;
}

.panel {
  position: absolute;
  top: 0;
  left: calc(50% - var(--panel-w) / 2);
  width: var(--panel-w);
  height: var(--panel-h);
  transform-style: preserve-3d;
  transition: transform 1.05s cubic-bezier(.2,.8,.16,1), filter .65s ease;
}

.face {
  position: absolute;
  inset: 0;
  display: block;
  background-repeat: no-repeat;
  background-size: calc(var(--panel-w) * 3) var(--panel-h);
  background-color: var(--paper);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  box-shadow: inset 0 0 0 1px rgba(57, 69, 62, .08);
}

.outside { background-image: url("assets/exterior.png"); }
.inside { background-image: url("assets/interior.png"); transform: rotateY(180deg); }
.outside-left, .inside-left { background-position: left center; }
.outside-middle, .inside-middle { background-position: center center; }
.outside-right, .inside-right { background-position: right center; }

.view-cover .panel-left { transform: translateX(0) rotateY(0); z-index: 1; filter: brightness(.9); }
.view-cover .panel-middle { transform: translateX(2px) rotateY(0); z-index: 2; filter: brightness(.95); }
.view-cover .panel-right { transform: translateX(4px) rotateY(0); z-index: 3; }
.view-outside .panel-left { transform: translateX(calc(var(--panel-w) * -1)) rotateY(0); z-index: 1; }
.view-outside .panel-middle { transform: translateX(0) rotateY(0); z-index: 2; }
.view-outside .panel-right { transform: translateX(var(--panel-w)) rotateY(0); z-index: 3; }
.view-inside .panel-left { transform: translateX(calc(var(--panel-w) * -1)) rotateY(180deg); z-index: 1; }
.view-inside .panel-middle { transform: translateX(0) rotateY(180deg); z-index: 2; }
.view-inside .panel-right { transform: translateX(var(--panel-w)) rotateY(180deg); z-index: 3; }

.brochure::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -22px;
  width: var(--panel-w);
  height: 24px;
  border-radius: 50%;
  background: rgba(37, 46, 42, .22);
  filter: blur(14px);
  transform: translateX(-50%);
  transition: width 1s ease, opacity 1s ease;
}
.brochure:not(.view-cover)::after { width: var(--full-w); opacity: .52; }

.tap-cue {
  position: absolute;
  z-index: 8;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-radius: 999px;
  color: white;
  background: rgba(35, 51, 46, .88);
  box-shadow: 0 8px 26px rgba(27, 38, 34, .22);
  font-size: .9rem;
  letter-spacing: .03em;
  transition: opacity .35s ease, transform .35s ease;
}
.tap-cue i { width: 8px; height: 8px; border-right: 1.5px solid white; border-bottom: 1.5px solid white; transform: rotate(45deg) translateY(-2px); }
.brochure:not(.view-cover) .tap-cue { opacity: 0; transform: translate(-50%, 8px); pointer-events: none; }

.brochure:focus-visible .panel-right { outline: 4px solid #9a6d3c; outline-offset: 7px; }
.controls { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 10px; }
.view-status { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 2px; }
.step { padding: 7px 12px; border: 1px solid var(--line); border-radius: 999px; color: #6d7872; font-size: .84rem; }
.step.active { color: white; border-color: var(--forest); background: var(--forest); }
.control { min-height: 48px; padding: 13px 24px; border-radius: 999px; text-decoration: none; border: 1px solid var(--forest); cursor: pointer; transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.control:hover { transform: translateY(-2px); box-shadow: 0 8px 18px rgba(40, 56, 49, .14); }
.control:disabled { opacity: .42; cursor: default; transform: none; box-shadow: none; }
.primary { background: var(--forest); color: white; }
.secondary { background: rgba(255,255,255,.65); color: var(--forest); }
.hint { margin: 12px 0 0; color: #6a756f; font-size: .9rem; text-align: center; }

@media (max-width: 760px) {
  .page-shell { padding-inline: 14px; }
  .intro { margin-bottom: 8px; }
  .stage { min-height: 520px; height: 112vw; max-height: 660px; }
  .brochure {
    --full-w: min(96vw, 680px);
    --panel-w: calc(var(--full-w) / 3);
    --panel-h: calc(var(--full-w) * .768);
    transform: rotate(90deg) scale(.94);
  }
  .tap-cue { bottom: 12px; padding: 8px 13px; font-size: .78rem; }
  .controls { margin-top: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .panel, .brochure::after, .tap-cue, .control { transition-duration: .01ms; }
}