html, body {
  margin: 0;
  background: #fff;
  height: 100%;
}

.fs {
  --ink: #111114;
  --soft: rgba(17, 17, 20, 0.55);
  --faint: rgba(17, 17, 20, 0.08);
  --line: rgba(17, 17, 20, 0.12);
  position: fixed;
  inset: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 400px;
  background: #fff;
  color: var(--ink);
  font: 13px/1.45 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", system-ui, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

.fs-stage {
  position: relative;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  user-select: none;
}

.fc-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
  opacity: 0;
  transition: opacity 0.6s ease;
}

.fs[data-ready] .fc-canvas { opacity: 1; }
.fc-canvas[data-grabbing] { cursor: grabbing; }

.fs-sr {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.fs-fail {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  margin: 0;
  max-width: 80%;
  text-align: center;
  color: var(--soft);
}

.fs-corner {
  position: absolute;
  top: max(18px, env(safe-area-inset-top));
  left: max(18px, env(safe-area-inset-left));
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}

.fs-badge {
  font-size: 19px;
  font-weight: 650;
  letter-spacing: -0.03em;
}

.fs-credit {
  margin: 0;
  max-width: 240px;
  font-size: 12px;
  color: rgba(17, 17, 20, 0.5);
}

.fs-guide {
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: max(22px, env(safe-area-inset-bottom));
  margin: 0;
  text-align: center;
  font-size: 12px;
  letter-spacing: 0.01em;
  color: rgba(17, 17, 20, 0.45);
  pointer-events: none;
  transition: opacity 0.8s ease 0.2s;
}

.fs:not([data-ready]) .fs-guide,
.fs:not([data-ready]) .fs-corner { opacity: 0; }

.fs-fold { display: none; }

.fs-drop {
  position: absolute;
  inset: 14px;
  z-index: 3;
  display: grid;
  place-items: center;
  border: 1.5px dashed rgba(17, 17, 20, 0.35);
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(6px);
  font-size: 15px;
  font-weight: 600;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.fs[data-dragging] .fs-drop { opacity: 1; }

.fs-panel {
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  border-left: 1px solid var(--faint);
  background: #fcfcfb;
  display: flex;
  flex-direction: column;
}

.fs-head { padding: 26px 24px 6px; }
.fs-head h1 { margin: 0; font-size: 22px; font-weight: 650; letter-spacing: -0.025em; }
.fs-head p { margin: 4px 0 0; color: var(--soft); }

.fs-section { padding: 18px 24px; border-bottom: 1px solid var(--faint); }
.fs-section h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 600;
}

.fs-n {
  display: grid;
  place-items: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--ink);
  color: #fff;
  font-size: 10.5px;
  font-weight: 600;
}

.fs-sub { font-weight: 400; color: var(--soft); }
.fs-section h2 .fs-link { margin-left: auto; }

.fs-surprise {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  text-decoration: none;
}

.fs-surprise span {
  text-decoration: underline;
  text-decoration-color: rgba(17, 17, 20, 0.3);
  text-underline-offset: 3px;
}

.fs-label { margin: 14px 0 7px; font-size: 12px; color: var(--soft); }

.fs-cover { display: flex; gap: 14px; align-items: flex-start; }

.fs-proof {
  flex: none;
  width: 104px;
  height: auto;
  border-radius: 6px;
  box-shadow: 0 0 0 1px var(--faint), 0 6px 14px -8px rgba(17, 17, 20, 0.35);
  cursor: crosshair;
}

.fs-cover-side { min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.fs-note { margin: 0; font-size: 12px; color: var(--soft); }
.fs-pages { margin-top: 8px; }
.fs-error { margin: 0; font-size: 12px; color: #b4232f; }

.fs-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-weight: 550;
  cursor: pointer;
  align-self: flex-start;
}

.fs-button:hover { background: #f4f4f2; }
.fs-primary { border-color: var(--ink); background: var(--ink); color: #fff; }
.fs-primary:hover { background: #2a2a30; }
.fs-button:disabled { opacity: 0.5; cursor: default; }

.fs-link {
  padding: 0;
  border: 0;
  background: none;
  color: var(--ink);
  font: inherit;
  font-size: 12px;
  font-weight: 500;
  text-decoration: underline;
  text-decoration-color: rgba(17, 17, 20, 0.3);
  text-underline-offset: 3px;
  cursor: pointer;
}

.fs-chips { display: flex; flex-wrap: wrap; gap: 6px; }

.fs-chip {
  height: 30px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-size: 12.5px;
  cursor: pointer;
}

.fs-chip[aria-checked="true"] {
  border-color: var(--ink);
  background: var(--ink);
  color: #fff;
}

.fs-hint {
  display: flex;
  align-items: center;
  gap: 7px;
  margin: 10px 0 0;
  font-size: 12px;
  color: var(--soft);
}

.fs-picked {
  flex: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(17, 17, 20, 0.2);
}

.fs-range {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 14px;
  font-size: 12px;
  color: var(--soft);
}

.fs-range input { width: 100%; accent-color: var(--ink); }

.fs-check {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  cursor: pointer;
}

.fs-check input { width: 15px; height: 15px; margin: 0; accent-color: var(--ink); }

.fs-swatches { display: flex; flex-wrap: wrap; gap: 8px; }
.fs-swatches:has(.fs-foil) { gap: 4px; margin: -4px 0 0 -6px; }

.fs-swatch {
  width: 30px;
  height: 30px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--c);
  box-shadow: inset 0 0 0 1px rgba(17, 17, 20, 0.14);
  cursor: pointer;
}

.fs-swatch[aria-checked="true"] { outline: 2px solid var(--ink); outline-offset: 3px; }

.fs-foil {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
}

.fs-foil svg { overflow: visible; filter: drop-shadow(0 1px 1px rgba(40, 30, 10, 0.22)); }
.fs-foil[aria-checked="true"] { background: #fff; box-shadow: inset 0 0 0 1.5px var(--ink); }

.fs-letter, .fs-input {
  display: block;
  width: 100%;
  box-sizing: border-box;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  outline: none;
}

.fs-letter {
  padding: 10px 12px;
  resize: vertical;
  min-height: 150px;
  font: 500 21px/1.25 "Caveat", "Segoe Script", cursive;
}

.fs-input {
  height: 36px;
  margin-top: 8px;
  padding: 0 12px;
  font: inherit;
}

.fs-letter:focus, .fs-input:focus {
  border-color: rgba(17, 17, 20, 0.4);
  box-shadow: 0 0 0 3px rgba(17, 17, 20, 0.06);
}

.fs-share {
  position: sticky;
  bottom: 0;
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 14px 24px max(16px, env(safe-area-inset-bottom));
  background: rgba(252, 252, 251, 0.92);
  border-top: 1px solid var(--faint);
  backdrop-filter: blur(12px);
}

.fs-make { width: 100%; height: 42px; align-self: stretch; }
.fs-done { display: flex; flex-direction: column; gap: 10px; }
.fs-url { display: flex; gap: 6px; }

.fs-url input {
  flex: 1;
  min-width: 0;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-size: 12.5px;
}

.fs-url .fs-button { height: 38px; }

button:focus-visible, .fs-chip:focus-visible {
  outline: 2px solid #3b82f6;
  outline-offset: 2px;
}

@media (max-width: 860px) {
  .fs { grid-template-columns: minmax(0, 1fr); grid-template-rows: 46svh minmax(0, 1fr); }
  .fs-panel {
    border-left: 0;
    border-top: 1px solid var(--faint);
    border-radius: 20px 20px 0 0;
    box-shadow: 0 -12px 30px -18px rgba(17, 17, 20, 0.25);
  }
  .fs-head { padding: 20px 18px 2px; }
  .fs-head h1 { font-size: 19px; }
  .fs-section { padding: 16px 18px; }
  .fs-share { padding-left: 18px; padding-right: 18px; }
  .fs[data-reading] { grid-template-rows: 78svh minmax(0, 1fr); }
  .fs-fold {
    position: absolute;
    right: 14px;
    bottom: max(10px, env(safe-area-inset-bottom));
    z-index: 3;
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: 50%;
    background: #fff;
    color: var(--ink);
    cursor: pointer;
  }
  .fs[data-collapsed] { grid-template-rows: minmax(0, 1fr) 0; }
  .fs[data-collapsed] .fs-panel { display: none; }
  .fs[data-collapsed] .fs-fold svg { transform: rotate(180deg); }
}