:root {
  --bg: #0e1116;
  --bg-elev: #161b22;
  --bg-elev-2: #1c2330;
  --border: #2a3240;
  --text: #e6edf3;
  --text-dim: #8b98a9;
  --accent: #4f8cff;
  --accent-hover: #6ba0ff;
  --accent-soft: rgba(79, 140, 255, 0.14);
  --good: #3fb950;
  --radius: 12px;
  --shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

/* 确保 hidden 属性始终生效（覆盖下方 display:flex/grid 等规则） */
[hidden] { display: none !important; }

html, body {
  margin: 0;
  height: 100%;
}

body {
  background: radial-gradient(1200px 600px at 80% -10%, #182234 0%, var(--bg) 55%);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  flex-direction: column;
  min-height: 100%;
}

/* ---------- Top bar ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  background: rgba(14, 17, 22, 0.7);
  backdrop-filter: blur(8px);
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo { font-size: 32px; line-height: 1; }
.topbar h1 { margin: 0; font-size: 20px; letter-spacing: 0.5px; }
.tagline { margin: 2px 0 0; color: var(--text-dim); font-size: 13px; }
.ghost-link { color: var(--text-dim); font-size: 13px; text-decoration: none; }
.ghost-link:hover { color: var(--accent); }

/* ---------- Layout ---------- */
.layout {
  flex: 1;
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 18px;
  padding: 18px;
  min-height: 0;
}
.panel {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.controls {
  padding: 8px 18px 20px;
  overflow-y: auto;
  max-height: calc(100vh - 150px);
}
.result { display: flex; flex-direction: column; min-height: 0; }

/* ---------- Steps ---------- */
.step { padding: 16px 0; border-bottom: 1px solid var(--border); }
.step:last-of-type { border-bottom: none; }
.step h2 {
  display: flex; align-items: center; gap: 10px;
  font-size: 15px; margin: 0 0 12px;
}
.num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent);
  font-size: 13px; font-weight: 700;
}

/* ---------- Dropzone ---------- */
.dropzone {
  border: 1.5px dashed var(--border);
  border-radius: var(--radius);
  padding: 18px 16px;
  text-align: center;
  transition: border-color 0.15s, background 0.15s;
}
.dropzone.dragover { border-color: var(--accent); background: var(--accent-soft); }
.dropzone > p { margin: 0 0 12px; color: var(--text-dim); font-size: 14px; }
.dropzone-sm { padding: 14px; }
.btn-row { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.hint { color: var(--text-dim); font-size: 12px; margin: 10px 0 0; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 6px; cursor: pointer;
  background: var(--bg-elev-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 9px 16px; font-size: 14px; font-weight: 500;
  transition: background 0.15s, border-color 0.15s, transform 0.05s;
  user-select: none;
}
.btn:hover { border-color: var(--accent); }
.btn:active { transform: translateY(1px); }
.btn-outline { background: transparent; }
.btn-block { width: 100%; }
.btn-primary {
  background: var(--accent); border-color: var(--accent); color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-primary:disabled,
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.btn-primary:disabled:hover { background: var(--accent); border-color: var(--accent); }
.link-btn {
  background: none; border: none; color: var(--accent);
  cursor: pointer; font-size: 13px; padding: 0;
}
.link-btn:hover { text-decoration: underline; }

/* ---------- Tile status / preview ---------- */
.tile-status { margin-top: 12px; font-size: 13px; color: var(--text-dim); }
.count { color: var(--text); font-weight: 700; font-size: 15px; }
.tile-preview {
  margin-top: 10px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(38px, 1fr));
  gap: 4px;
}
.tile-preview canvas {
  width: 100%; aspect-ratio: 1; border-radius: 5px; display: block;
  background: var(--bg-elev-2);
}
.tile-preview .more {
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; color: var(--text-dim);
  background: var(--bg-elev-2); border-radius: 5px; aspect-ratio: 1;
}

/* ---------- Divider ---------- */
.divider {
  display: flex; align-items: center; gap: 10px;
  margin: 16px 0 14px; color: var(--text-dim); font-size: 12px;
}
.divider::before, .divider::after {
  content: ""; flex: 1; height: 1px; background: var(--border);
}

/* ---------- Search ---------- */
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 10px; }
.chip {
  padding: 5px 12px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--bg-elev-2);
  color: var(--text); font-size: 13px; cursor: pointer;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.active { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }

.search-row { display: flex; gap: 8px; }
.search-row input[type="text"] {
  flex: 1; min-width: 0; padding: 8px 10px;
  background: var(--bg-elev-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px; font-size: 14px;
}
.search-row select { width: 62px; padding: 8px 6px; }
.btn-sm { padding: 8px 14px; font-size: 13px; }

.search-status { color: var(--text-dim); font-size: 12px; margin: 8px 0 0; min-height: 15px; line-height: 1.4; }

.search-results {
  margin-top: 10px;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
  gap: 5px; max-height: 240px; overflow-y: auto; padding: 2px;
}
.result-thumb {
  position: relative; aspect-ratio: 1; border-radius: 6px; overflow: hidden;
  cursor: pointer; border: 2px solid transparent; background: var(--bg-elev-2);
}
.result-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.result-thumb::after {
  content: ""; position: absolute; inset: 0;
  background: rgba(0, 0, 0, 0.5); transition: background 0.12s;
}
.result-thumb.sel { border-color: var(--accent); }
.result-thumb.sel::after { background: transparent; }
.result-thumb .tick {
  position: absolute; top: 3px; right: 3px; z-index: 1;
  width: 16px; height: 16px; border-radius: 50%;
  background: var(--accent); color: #fff; font-size: 10px;
  display: flex; align-items: center; justify-content: center;
  opacity: 0; transform: scale(0.6); transition: opacity 0.12s, transform 0.12s;
}
.result-thumb.sel .tick { opacity: 1; transform: scale(1); }

.search-actions { display: flex; align-items: center; gap: 12px; margin-top: 12px; }
.search-actions .btn-sm { margin-left: auto; }

/* ---------- Target preview ---------- */.target-preview { margin-top: 12px; text-align: center; }
.target-preview canvas {
  max-width: 100%; max-height: 160px; border-radius: 8px;
  border: 1px solid var(--border);
}
.meta { display: block; margin-top: 6px; color: var(--text-dim); font-size: 12px; }

/* ---------- Fields ---------- */
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 13px; margin-bottom: 6px; }
.field label b { color: var(--accent); }
.field small { display: block; color: var(--text-dim); font-size: 11px; margin-top: 4px; }
.field-inline { display: grid; grid-template-columns: auto 90px; align-items: center; gap: 8px; }
.field-inline small { grid-column: 1 / -1; margin-top: 0; }

input[type="range"] {
  width: 100%; accent-color: var(--accent); cursor: pointer;
}
select, input[type="number"] {
  width: 100%; padding: 8px 10px;
  background: var(--bg-elev-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px; font-size: 14px;
}
input[type="number"] { text-align: center; }

.btn-primary.btn-block { margin-top: 6px; padding: 12px; font-size: 15px; }
.gen-hint { color: var(--text-dim); font-size: 12px; text-align: center; margin: 8px 0 0; }

/* ---------- Progress ---------- */
.progress-wrap { margin-top: 14px; }
.progress {
  height: 8px; background: var(--bg-elev-2);
  border-radius: 999px; overflow: hidden;
}
.progress-bar {
  height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover));
  transition: width 0.1s linear;
}
.progress-text { display: block; margin-top: 6px; font-size: 12px; color: var(--text-dim); text-align: center; }

/* ---------- Result ---------- */
.result-toolbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 16px; border-bottom: 1px solid var(--border); gap: 12px;
}
.result-toolbar .left { display: flex; align-items: center; gap: 16px; }
.zoom-label { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-dim); }
.zoom-label input { width: 130px; }
.result-toolbar .meta { margin: 0; }

.stage {
  flex: 1; position: relative; min-height: 0;
  background:
    linear-gradient(45deg, #0b0e13 25%, transparent 25%) 0 0/24px 24px,
    linear-gradient(-45deg, #0b0e13 25%, transparent 25%) 0 0/24px 24px,
    linear-gradient(45deg, transparent 75%, #0b0e13 75%) 0 0/24px 24px,
    linear-gradient(-45deg, transparent 75%, #0b0e13 75%) 12px 12px/24px 24px,
    var(--bg);
  border-radius: 0 0 var(--radius) var(--radius);
  overflow: hidden;
}
.empty-state {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: var(--text-dim); gap: 6px;
}
.empty-emoji { font-size: 52px; opacity: 0.6; }
.empty-state p { margin: 0; }
.canvas-scroll {
  position: absolute; inset: 0; overflow: auto; padding: 18px;
  display: flex; align-items: flex-start; justify-content: center;
}
#output {
  display: block; image-rendering: auto;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  background: #fff;
}

/* ---------- Footer ---------- */
.footer {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px; color: var(--text-dim); font-size: 12px;
  border-top: 1px solid var(--border);
}
.footer .dot { opacity: 0.5; }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .controls { max-height: none; }
  .result { min-height: 70vh; }
}