:root { color-scheme: dark; font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, sans-serif; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; background: radial-gradient(circle at top left, #283956, #0c1020 55%); color: #f3f6fb; }
.app { display: grid; grid-template-columns: 420px 1fr; gap: 18px; min-height: 100vh; padding: 18px; }
.panel { background: rgba(13,18,34,.86); border: 1px solid rgba(255,255,255,.12); border-radius: 22px; box-shadow: 0 24px 70px rgba(0,0,0,.32); }
.controls { padding: 24px; overflow: auto; }
h1 { margin: 0 0 8px; font-size: 30px; }
p { color: #b8c4d8; line-height: 1.45; }
.dropzone { display: grid; place-items: center; border: 2px dashed #5d77a7; border-radius: 16px; padding: 30px 16px; margin: 22px 0; cursor: pointer; background: rgba(255,255,255,.04); text-align: center; }
.dropzone.drag { border-color: #92c2ff; background: rgba(146,194,255,.12); }
.dropzone input { display: none; }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 14px; }
label { color: #dbe7fb; font-size: 13px; display: grid; gap: 7px; }
input, select, button { width: 100%; border-radius: 12px; border: 1px solid rgba(255,255,255,.16); background: #10182d; color: #fff; padding: 11px 12px; font: inherit; }
input[type="range"] { padding: 0; }
button { margin-top: 10px; border: 0; background: linear-gradient(135deg, #5ee0ff, #7d70ff); color: #06101f; font-weight: 800; cursor: pointer; }
button:disabled { opacity: .45; cursor: not-allowed; }
.status { min-height: 42px; font-size: 13px; }
.preview { position: relative; overflow: hidden; }
#viewer { width: 100%; height: 100%; min-height: calc(100vh - 36px); }
.hint { position: absolute; left: 18px; bottom: 16px; background: rgba(0,0,0,.45); padding: 8px 12px; border-radius: 999px; color: #d5e2f5; font-size: 13px; }
@media (max-width: 900px) { .app { grid-template-columns: 1fr; } #viewer { min-height: 520px; } }