* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: "Segoe UI", "Yu Gothic UI", sans-serif;
  background: #14181f; color: #dde3ea;
  height: 100vh; display: flex; flex-direction: column;
}
header { padding: 10px 16px; border-bottom: 1px solid #2a3140; }
header h1 { font-size: 18px; display: inline-block; margin-right: 12px; }
.tagline { display: inline-block; font-size: 12px; color: #8a94a6; }
main { flex: 1; display: flex; min-height: 0; }
#preview-pane { flex: 1; display: flex; flex-direction: column; min-width: 0; }
#canvas-wrap { flex: 1; overflow: auto; padding: 16px; background: #0d1015; }
#preview { display: block; margin: 0 auto; box-shadow: 0 0 24px rgba(0,0,0,.6); }
#zoom-bar { padding: 6px 16px; border-top: 1px solid #2a3140; font-size: 12px; display: flex; align-items: center; gap: 10px; }
#zoom { vertical-align: middle; width: 160px; }
#zoom-fit {
  padding: 4px 10px; font-size: 12px; background: #1c222d; color: #dde3ea;
  border: 1px solid #3a4356; border-radius: 4px; cursor: pointer;
}
#zoom-fit:hover { background: #26304082; border-color: #6db3f2; }
#panel-resizer {
  width: 6px; flex-shrink: 0; cursor: col-resize; position: relative; background: transparent;
}
#panel-resizer::after {
  content: ""; position: absolute; left: 2px; top: 0; bottom: 0; width: 2px; background: #2a3140;
}
#panel-resizer:hover::after, #panel-resizer.dragging::after { background: #6db3f2; }
#panel { width: 340px; flex-shrink: 0; overflow-y: auto; padding: 12px; }
.step { margin-bottom: 18px; }
.step h2 { font-size: 14px; color: #6db3f2; margin-bottom: 8px; }
.step label { display: block; font-size: 12px; margin: 6px 0 2px; color: #a8b2c2; }
.step input, .step select, .step button {
  width: 100%; padding: 5px 8px; font-size: 13px;
  background: #1c222d; color: #dde3ea; border: 1px solid #3a4356; border-radius: 4px;
}
.step input[type="range"] { padding: 0; }
.step button { cursor: pointer; margin-top: 8px; }
.step button:hover { background: #26304082; border-color: #6db3f2; }
.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.hint { font-size: 11px; color: #8a94a6; margin-top: 4px; line-height: 1.5; }
.ad-placeholder {
  margin-top: 12px; padding: 24px 0; text-align: center;
  border: 1px dashed #3a4356; border-radius: 4px; color: #5a6478; font-size: 12px;
}
.footer-link { margin-top: 10px; text-align: center; font-size: 11px; }
.footer-link a { color: #6a7688; }
.footer-link a:hover { color: #6db3f2; }
.step h3.sub { font-size: 12px; color: #a8b2c2; margin: 12px 0 4px; }
.calib-actions { display: flex; justify-content: flex-end; margin-top: 8px; }
.calib-actions .calib-reset { width: auto; padding: 5px 12px; font-size: 12px; }
.zone-item-row { display: flex; gap: 4px; margin-top: 4px; }
.zone-item-row .zone-item {
  flex: 1; height: 28px; box-sizing: border-box; text-align: left; margin-top: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.zone-item.selected { border-color: #6db3f2; background: #223046; }
.zone-item-row .zone-item-delete {
  flex-shrink: 0; flex-grow: 0; width: 32px; height: 28px; box-sizing: border-box;
  padding: 0; margin-top: 0; line-height: 26px; color: #f2a6a6;
}
.zone-item-delete:hover { background: #402626; border-color: #f26d6d; }
.zone-editor { margin-top: 10px; padding: 10px; border: 1px solid #2a3140; border-radius: 6px; }
button.primary { border-color: #2e6db3; background: #1d3a5c; font-weight: bold; }
button.primary:hover { background: #24507e; }
.panel-toolbar { display: flex; align-items: flex-start; gap: 8px; margin-bottom: 14px; }
.guide { flex: 1; min-width: 0; font-size: 12px; }
.guide summary { cursor: pointer; color: #6db3f2; }
.guide ol { margin: 8px 0 8px 18px; line-height: 1.7; }
.guide p { margin: 6px 0; line-height: 1.6; color: #a8b2c2; }
.settings-io { display: flex; gap: 6px; flex-shrink: 0; }
.settings-io button {
  padding: 6px 10px; font-size: 11px; white-space: nowrap;
  background: #1c222d; color: #dde3ea; border: 1px solid #3a4356; border-radius: 4px; cursor: pointer;
}
.settings-io button:hover { background: #26304082; border-color: #6db3f2; }

.tabs { display: flex; gap: 4px; margin-bottom: 14px; border-bottom: 1px solid #2a3140; }
.tab-btn {
  flex: 1; background: none; border: none; border-bottom: 2px solid transparent;
  color: #8a94a6; font-size: 13px; padding: 8px 4px; cursor: pointer; border-radius: 0;
}
.tab-btn:hover { color: #dde3ea; background: #1c222d82; }
.tab-btn.active { color: #6db3f2; border-bottom-color: #6db3f2; }
.step { display: none; }
.step.active { display: block; }

.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,.6);
  display: flex; align-items: center; justify-content: center; z-index: 100;
}
.modal-overlay[hidden] { display: none; }
.modal-box {
  position: relative; max-width: 480px; width: 90%; max-height: 80vh; overflow-y: auto;
  background: #1c222d; border: 1px solid #3a4356; border-radius: 8px; padding: 24px;
}
.modal-close {
  position: absolute; top: 8px; right: 8px; width: 28px; height: 28px;
  background: none; border: none; color: #8a94a6; font-size: 18px; line-height: 1; cursor: pointer;
}
.modal-close:hover { color: #dde3ea; }
.modal-box h2 { font-size: 16px; color: #6db3f2; margin-bottom: 12px; padding-right: 24px; }
.modal-box ol { margin: 8px 0 8px 18px; line-height: 1.7; font-size: 13px; }
.modal-box p { margin: 8px 0; line-height: 1.6; font-size: 13px; color: #a8b2c2; }