:root {
  color-scheme: light;
  --ink: #101114;
  --muted: #5f6368;
  --soft: #8b9097;
  --paper: #ffffff;
  --mist: #f6f7f9;
  --line: rgba(16, 17, 20, .09);
  --line-strong: rgba(16, 17, 20, .15);
  --blue: #0071e3;
  --green: #0c9f6b;
  --green-soft: rgba(12, 159, 107, .08);
  --danger: #ef5a6f;
  --shadow-card: rgba(16, 17, 20, .08) 0 0 0 1px, rgba(16, 17, 20, .06) 0 18px 54px;
  --shadow-soft: rgba(16, 17, 20, .07) 0 0 0 1px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", "PingFang TC", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 85% -10%, rgba(0, 113, 227, .10), transparent 26rem),
    radial-gradient(circle at 6% 2%, rgba(12, 159, 107, .10), transparent 24rem),
    linear-gradient(180deg, #fff 0%, #f7f8fa 74%, #fff 100%);
  letter-spacing: -0.02em;
}

button, input, a { font: inherit; }
button { transition: transform .16s ease, box-shadow .16s ease, background .16s ease; }
button:hover:not(:disabled), .download:hover, .file-picker span:hover, .portfolio-link:hover { transform: translateY(-1px); }
.shell { width: min(1180px, calc(100% - 40px)); margin: 0 auto; padding: 46px 0 64px; overflow-x: clip; }
.hero { margin-bottom: 24px; }
.hero-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}
.portfolio-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255,255,255,.88);
  box-shadow: var(--shadow-soft);
  text-decoration: none;
  font-size: 13px;
  font-weight: 720;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,.84);
  box-shadow: var(--shadow-soft);
  color: var(--muted);
  text-transform: none;
  letter-spacing: 0;
  font-size: 13px;
  font-weight: 680;
}
.eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 5px rgba(12, 159, 107, .12);
}
h1 { max-width: 860px; margin: 0 0 12px; font-size: clamp(2rem, 4vw, 3.4rem); line-height: 1.02; letter-spacing: -0.06em; font-weight: 760; }
h2 { margin: 0 0 14px; font-size: 18px; letter-spacing: -0.035em; }
.subtle, .status, .placeholder { color: var(--muted); }
.subtle { max-width: 760px; line-height: 1.72; font-size: clamp(1rem, 1.35vw, 1.12rem); }

.panel, .canvas-card, .result-card {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, .86);
  border-radius: 28px;
  box-shadow: var(--shadow-card);
  backdrop-filter: saturate(180%) blur(16px);
}
.controls { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; padding: 18px; margin-bottom: 18px; }
.file-picker input { display: none; }
.file-picker span, button, .download {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 42px; padding: 0 16px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255,255,255,.92);
  cursor: pointer;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
}
button.active { border-color: rgba(12, 159, 107, .36); color: #0f6b4b; background: var(--green-soft); }
button.primary { background: var(--ink); color: #fff; border: none; font-weight: 800; box-shadow: rgba(16,17,20,.12) 0 12px 28px; }
button:disabled { opacity: 0.45; cursor: not-allowed; box-shadow: none; }
.tool-row { display: flex; gap: 8px; flex-wrap: wrap; }
.slider { display: flex; align-items: center; gap: 10px; color: var(--muted); }
.slider input { accent-color: var(--green); }
.mode-picker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 42px;
  margin: 0;
  padding: 6px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255,255,255,.64);
}
.mode-picker legend { padding: 0 4px; color: #0f6b4b; font-size: 12px; font-weight: 740; }
.mode-picker label { display: inline-flex; align-items: center; gap: 5px; color: var(--ink); }
.mode-picker input { accent-color: var(--green); }
.status { margin: 0; flex: 1 1 260px; }
.status.error { color: var(--danger); }
.status.ok { color: var(--green); }

.workspace { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.canvas-card, .result-card { padding: 18px; min-width: 0; }
.canvas-wrap, .result-frame {
  position: relative;
  min-height: 420px;
  border-radius: 20px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(255,255,255,.78), rgba(241,243,246,.92)),
    var(--mist);
  border: 1px solid var(--line);
  display: grid;
  place-items: center;
}
.canvas-wrap canvas { position: absolute; inset: 0; width: 100%; height: 100%; touch-action: none; }
.canvas-wrap.empty canvas { display: none; }
.placeholder { padding: 24px; text-align: center; }
#resultImage { max-width: 100%; max-height: 70vh; border-radius: 16px; box-shadow: var(--shadow-soft); }
.download { margin-top: 14px; }

@media (max-width: 840px) {
  .workspace { grid-template-columns: 1fr; }
  .canvas-wrap, .result-frame { min-height: 320px; }
}

@media (max-width: 640px) {
  .shell { width: min(100% - 24px, 1180px); padding: 26px 0 34px; }
  h1 { font-size: clamp(30px, 12vw, 48px); }
  .controls { align-items: stretch; padding: 12px; }
  .file-picker span, button, .download { width: 100%; min-height: 44px; }
  .tool-row, .slider, .mode-picker { width: 100%; }
  .tool-row button { flex: 1 1 140px; }
  .slider { justify-content: space-between; }
  .slider input { min-width: 0; flex: 1 1 auto; }
  .mode-picker { border-radius: 18px; flex-wrap: wrap; justify-content: center; }
  .status { flex-basis: 100%; }
  .canvas-card, .result-card { padding: 12px; border-radius: 18px; }
  .canvas-wrap, .result-frame { min-height: min(72vw, 300px); }
}