.design-shell {
  margin: 0;
  position: relative;
  background-color: #171819;
  color: #fff;
  min-height: 100vh;
  overflow-x: hidden;
}
.design-room-stage {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-color: #171819;
  animation: design-room-enter 0.32s ease both;
}
.design-room-stage canvas {
  position: absolute;
  inset: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  display: block;
}
.design-room-poster {
  position: absolute;
  inset: 0;
  z-index: 2;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  opacity: 1;
  transition: opacity 0.3s ease;
}
.design-room-poster.is-fading {
  opacity: 0;
}
.design-room-fallback {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: none;
  align-items: center;
  justify-content: center;
  color: #888;
  font-family: system-ui, sans-serif;
  background: linear-gradient(180deg, #1f1f23 0%, #111 100%);
}
.design-room-fallback.visible {
  display: flex;
}
.design-shell-main {
  position: relative;
  z-index: 2;
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 24px 96px;
  font-family: system-ui, sans-serif;
}
.design-shell .site-footer {
  position: relative;
  z-index: 2;
}
.design-shell-card {
  background: rgba(24, 25, 30, 0.78);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 18px;
  padding: 36px 32px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: 0 18px 48px rgba(0, 0, 0, 0.45);
  animation: design-card-enter 0.32s cubic-bezier(0.2, 0.7, 0.25, 1) both;
}

@keyframes design-room-enter {
  from {
    opacity: 0;
    transform: scale(1.012);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes design-card-enter {
  from {
    opacity: 0;
    transform: translateY(16px) scale(0.985);
    filter: blur(3px);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
    filter: blur(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .design-room-stage,
  .design-shell-card {
    animation: none;
  }
}
.design-shell-tag {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #9aa0a6;
}
.design-shell-title {
  margin: 0 0 16px;
  font-size: 28px;
  font-weight: 600;
}
.design-shell-lead {
  margin: 0 0 16px;
  color: #cfd2d6;
  line-height: 1.5;
}
.design-shell-list {
  margin: 0 0 18px;
  padding-left: 20px;
  color: #cfd2d6;
  line-height: 1.5;
}
.design-shell-list code {
  background: rgba(255, 255, 255, 0.08);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 13px;
}
.design-shell-status {
  margin: 18px 0 22px;
  padding: 12px 14px;
  border-radius: 10px;
  background: rgba(184, 119, 255, 0.12);
  color: #d6c0ff;
  font-size: 14px;
  border: 1px solid rgba(184, 119, 255, 0.25);
}
.design-shell-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.design-shell-btn {
  display: inline-flex;
  align-items: center;
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
}
.design-shell-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}
.design-shell-btn-primary {
  background: #4a78ff;
  border-color: #4a78ff;
}
.design-shell-btn-primary:hover {
  background: #3a64e0;
  border-color: #3a64e0;
}

/* ---- Build form (Slice 5) ---- */
.design-build-form { display: block; margin-top: 16px; }
.design-build-fieldset {
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 0 0 14px;
}
.design-build-fieldset legend {
  padding: 0 6px;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #9aa0a6;
}
.design-build-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
}
.design-build-grid label,
.design-build-checks label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  color: #cfd2d6;
}
.design-build-checks {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 6px;
}
.design-build-checks label {
  flex-direction: row;
  align-items: center;
  gap: 8px;
}
.design-build-fieldset input,
.design-build-fieldset select,
.design-build-fieldset textarea {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  color: #fff;
  border-radius: 6px;
  padding: 6px 8px;
  font: inherit;
}
.design-build-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 8px;
}
.design-build-status {
  margin-top: 16px;
  padding: 10px 14px;
  border-radius: 10px;
  font: 14px system-ui, sans-serif;
  background: rgba(255,255,255,0.06);
  color: #d6d8dc;
  border: 1px solid rgba(255,255,255,0.1);
}
.design-build-status[data-kind="error"] {
  background: rgba(255,77,79,0.15);
  border-color: rgba(255,77,79,0.4);
  color: #ffb3b5;
}
.design-build-status[data-kind="success"] {
  background: rgba(64,192,120,0.15);
  border-color: rgba(64,192,120,0.4);
  color: #b6f0c8;
}
.design-build-result {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-family: system-ui, sans-serif;
}
.design-build-result-title { font-size: 18px; margin: 0 0 12px; }
.design-build-subtitle {
  font-size: 14px;
  margin: 16px 0 8px;
  color: #cfd2d6;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}
.design-build-summary {
  display: grid;
  grid-template-columns: max-content 1fr;
  column-gap: 16px;
  row-gap: 6px;
  margin: 0;
  font-size: 14px;
  color: #cfd2d6;
}
.design-build-summary dt { color: #9aa0a6; }
.design-build-summary dd { margin: 0; color: #fff; }
.design-build-chip-list {
  display: flex; flex-wrap: wrap; gap: 8px;
  list-style: none; padding: 0; margin: 0;
}
.design-build-chip {
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.1);
  color: #fff;
  font-size: 13px;
}
.design-build-chip-warn {
  background: rgba(184,119,255,0.18);
  border-color: rgba(184,119,255,0.4);
  color: #d6c0ff;
}
.design-build-issue-list {
  list-style: none; padding: 0; margin: 0;
  display: flex; flex-direction: column; gap: 8px;
}
.design-build-issue {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 8px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  font-size: 13px;
  align-items: center;
}
.design-build-issue-severity {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 11px;
  color: #9aa0a6;
}
.design-build-issue-needs_review { border-color: rgba(184,119,255,0.4); }
.design-build-issue-needs_review .design-build-issue-severity { color: #d6c0ff; }
.design-build-issue-warning { border-color: rgba(255,176,32,0.4); }
.design-build-issue-warning .design-build-issue-severity { color: #ffd58a; }
.design-build-issue-error { border-color: rgba(255,77,79,0.5); }
.design-build-issue-error .design-build-issue-severity { color: #ffb3b5; }
.design-build-json {
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 10px;
  background: rgba(0,0,0,0.4);
  border: 1px solid rgba(255,255,255,0.1);
  color: #cfd2d6;
  font-family: ui-monospace, monospace;
  font-size: 12px;
  max-height: 320px;
  overflow: auto;
}