:root {
  color-scheme: dark;
  --bg: #070b12;
  --panel: #0f1624;
  --panel-border: #28364f;
  --text: #eaf2ff;
  --muted: #9ab0d1;
  --accent: #66b3ff;
  --accent-strong: #3f94f8;
  --ok: #6be7b6;
  --error: #ff8e8e;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% -20%, #11203f 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #162f5b 0%, transparent 50%),
    var(--bg);
}

.app-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.2rem;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.eyebrow {
  margin: 0;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}

h1 {
  margin: 0.25rem 0 0;
  font-size: clamp(1.4rem, 3vw, 2rem);
}

#glb-input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.upload-button {
  border: 1px solid #7bc2ff;
  background: linear-gradient(160deg, var(--accent), var(--accent-strong));
  color: #001028;
  font-weight: 700;
  padding: 0.75rem 1rem;
  border-radius: 0.8rem;
  cursor: pointer;
  transition: transform 140ms ease, box-shadow 140ms ease;
  box-shadow: 0 10px 30px rgba(67, 140, 255, 0.28);
}

.upload-button:hover {
  transform: translateY(-1px);
}

.upload-button:active {
  transform: translateY(0);
}

.viewer-layout {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 1rem;
}

.panel {
  position: relative;
  border-radius: 1rem;
  border: 1px solid var(--panel-border);
  background: linear-gradient(160deg, rgba(20, 30, 49, 0.8), rgba(11, 17, 30, 0.8));
  backdrop-filter: blur(8px);
}

.viewer-panel {
  min-height: 68vh;
  overflow: hidden;
}

#viewer-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.status-pill {
  position: absolute;
  left: 1rem;
  bottom: 1rem;
  z-index: 2;
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  border: 1px solid #3c4f72;
  background: rgba(9, 14, 24, 0.78);
  color: var(--muted);
  font-size: 0.87rem;
}

.status-pill.ok {
  color: var(--ok);
  border-color: rgba(107, 231, 182, 0.55);
}

.status-pill.error {
  color: var(--error);
  border-color: rgba(255, 142, 142, 0.6);
}

.loading-overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  gap: 0.7rem;
  background: rgba(8, 12, 22, 0.72);
}

.hidden {
  display: none;
}

.spinner {
  width: 2rem;
  height: 2rem;
  border-radius: 999px;
  border: 3px solid rgba(133, 170, 223, 0.22);
  border-top-color: #93c5ff;
  animation: spin 900ms linear infinite;
  margin: 0 auto;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.tips-panel {
  padding: 1.1rem;
}

.tips-panel h2 {
  margin-top: 0;
}

.tips-panel ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--muted);
  display: grid;
  gap: 0.5rem;
}

@media (max-width: 950px) {
  .viewer-layout {
    grid-template-columns: 1fr;
  }

  .viewer-panel {
    min-height: 56vh;
  }
}