* { box-sizing: border-box; }
:root { font-family: "Segoe UI", "Lucida Grande", sans-serif; color: #303030; background: #c4c4c4; }
body { min-width: 320px; min-height: 100vh; margin: 0; background: linear-gradient(#e2e2e2, #c4c4c4); }
.app-shell { width: min(820px, 100%); min-height: 100vh; margin: 0 auto; padding: 18px 24px 16px; display: flex; flex-direction: column; }
.app-header { text-align: center; margin-bottom: 12px; }
h1 { margin: 0; font-size: 21px; font-weight: 650; }
.app-header p { margin: 3px 0 0; color: #777; font-size: 13px; }
.segment-bar { align-self: center; display: flex; padding: 2px; border: 1px solid #858585; border-radius: 5px; background: #b1b1b1; }
.segment-option { position: relative; cursor: pointer; }
.segment-option input { position: absolute; opacity: 0; pointer-events: none; }
.segment-option span { display: block; min-width: 84px; padding: 7px 14px; border: 1px solid #a5a5a5; background: linear-gradient(#f8f8f8, #d8d8d8); color: #333; text-align: center; font-size: 13px; }
.segment-option:first-child span { border-radius: 3px 0 0 3px; }
.segment-option:last-child span { border-radius: 0 3px 3px 0; }
.segment-option input:checked + span { background: linear-gradient(#7a7a7a, #5e5e5e); color: #fff; font-weight: 600; }
.segment-option input:focus-visible + span { outline: 2px solid #0000fe; outline-offset: 2px; }
.workspace { flex: 1; display: grid; grid-template-columns: 1fr auto 1fr; gap: 16px; align-items: center; padding-top: 18px; }
.editor-column { min-width: 0; display: flex; flex-direction: column; align-items: center; gap: 8px; }
.preview-card { width: 260px; height: 260px; padding: 8px; display: grid; place-items: center; overflow: hidden; border: 1px solid #8f8f8f; border-radius: 3px; background: #c7c7c7; }
.dropzone { cursor: pointer; }
.dropzone.drag-active { border: 2px solid #0000fe; background: #d9dded; }
.preview-card img { display: block; max-width: 100%; max-height: 100%; object-fit: contain; }
.preview-card canvas { display: none; }
.placeholder { color: #777; font-size: 14px; line-height: 1.4; text-align: center; }
.button { min-height: 32px; padding: 0 14px; border: 1px solid #8e8e8e; border-radius: 5px; color: #333; background: linear-gradient(#fff, #e9e9e9 48%, #c9c9c9); font: inherit; cursor: pointer; }
.button:hover:not(:disabled) { border-color: #6d6d6d; background: #f7f7f7; }
.button:active:not(:disabled) { background: #bdbdbd; }
.button:focus-visible, select:focus-visible, .dropzone:focus-visible { outline: 2px solid #0000fe; outline-offset: 2px; }
.button:disabled { color: #999; background: #d2d2d2; cursor: not-allowed; }
.accent { min-width: 170px; min-height: 44px; border-color: #0000b5; border-radius: 7px; color: #fff; background: linear-gradient(#4b65ff, #142bda 45%, #0000a8); font-weight: 700; }
.accent:hover:not(:disabled) { background: #3049ed; }
.action-column { display: flex; align-items: center; justify-content: center; }
.download-row { display: flex; gap: 6px; align-items: center; }
select { height: 32px; padding: 0 4px; border: 1px solid #8e8e8e; border-radius: 5px; background: #eee; color: #333; font: inherit; }
.status { min-height: 20px; margin: 10px 0 0; color: #555; font-size: 12px; text-align: center; }
.status.error { color: #9b2020; }
.author-callout { height: clamp(64px, 12vw, 112px); margin: -2px -8px -4px; pointer-events: none; }
.author-arrow { width: 100%; height: 100%; overflow: visible; }
.author-arrow path { fill: none; stroke: #0000fe; stroke-width: 22; stroke-linecap: round; stroke-linejoin: round; }
footer { margin-top: auto; padding-top: 4px; text-align: right; font-size: 12px; }
footer a { color: #555; text-decoration: none; }
footer a:hover { color: #0000fe; }
@media (max-width: 720px) {
  .app-shell { padding: 14px 12px 12px; }
  .workspace { grid-template-columns: 1fr; gap: 20px; padding-top: 16px; }
  .action-column { order: 2; }
  .editor-column:last-child { order: 3; }
  .segment-option span { min-width: 0; padding-inline: 10px; }
  .preview-card { width: min(260px, 82vw); height: min(260px, 82vw); }
  .download-row { width: min(260px, 82vw); }
  .download-row .button { flex: 1; }
  .author-callout { height: 70px; margin-top: 4px; }
  .author-arrow path { stroke-width: 18; }
}
@media (max-width: 390px) { .segment-option span { padding-inline: 7px; font-size: 12px; } }