:root {
  color-scheme: light;
  --bg-accent: radial-gradient(circle at top left, rgba(16, 123, 121, 0.22), transparent 36%),
    radial-gradient(circle at top right, rgba(241, 105, 67, 0.18), transparent 30%),
    linear-gradient(180deg, #f9f5ee 0%, #f4ebdd 100%);
  --panel: rgba(255, 253, 248, 0.84);
  --panel-border: rgba(36, 51, 66, 0.14);
  --text: #1e2b32;
  --muted: #5a6a72;
  --primary: #0f7b79;
  --primary-soft: rgba(15, 123, 121, 0.12);
  --shadow: 0 20px 50px rgba(47, 46, 37, 0.12);
  --radius: 28px;
  --font-sans: "Segoe UI Variable", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg-accent);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image: linear-gradient(rgba(15, 123, 121, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 123, 121, 0.04) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.32), transparent 70%);
  pointer-events: none;
}

.page-shell {
  width: min(1440px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 32px 0 48px;
}

.hero,
.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(320px, 0.9fr);
  gap: 24px;
  align-items: start;
}

.hero {
  align-items: end;
  margin-bottom: 24px;
}

.eyebrow,
.section-label {
  margin: 0 0 8px;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--primary);
}

.hero h1,
.panel h2 {
  margin: 0;
}

.hero h1 {
  font-size: clamp(2rem, 3vw, 3.8rem);
  line-height: 1.05;
}

.hero-copy {
  max-width: 720px;
  margin: 18px 0 0;
  font-size: 1.06rem;
  line-height: 1.7;
  color: var(--muted);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.stat-card,
.panel {
  backdrop-filter: blur(14px);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow);
}

.stat-card {
  border-radius: 22px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stat-card span,
.support-text,
.tips,
.dropzone-subtitle,
.export-status {
  color: var(--muted);
}

.stat-card strong {
  font-size: 1.7rem;
}

.panel {
  border-radius: var(--radius);
  padding: 24px;
}

.upload-panel,
.sheet-panel {
  margin-bottom: 24px;
}

.sidebar {
  display: grid;
  gap: 24px;
}

.panel-heading {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 18px;
}

.panel h2 {
  font-size: 1.3rem;
}

.support-text {
  margin: 0;
  max-width: 300px;
  line-height: 1.6;
  font-size: 0.95rem;
}

.dropzone {
  display: grid;
  place-items: center;
  min-height: 180px;
  padding: 24px;
  border-radius: 22px;
  border: 2px dashed rgba(15, 123, 121, 0.3);
  background:
    linear-gradient(180deg, rgba(15, 123, 121, 0.08), rgba(15, 123, 121, 0.02)),
    rgba(255, 255, 255, 0.45);
  text-align: center;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.dropzone:hover,
.dropzone.is-active {
  transform: translateY(-2px);
  border-color: var(--primary);
  background:
    linear-gradient(180deg, rgba(15, 123, 121, 0.14), rgba(15, 123, 121, 0.03)),
    rgba(255, 255, 255, 0.72);
}

.dropzone-title {
  display: block;
  font-size: 1.16rem;
  font-weight: 700;
}

.dropzone-subtitle {
  display: block;
  margin-top: 8px;
}

.canvas-frame {
  position: relative;
  overflow: hidden;
  border-radius: 24px;
  background:
    linear-gradient(180deg, rgba(36, 51, 66, 0.04), rgba(36, 51, 66, 0.08)),
    #fbfaf7;
  border: 1px solid rgba(36, 51, 66, 0.08);
  min-height: 420px;
}

#sheetCanvas,
#previewCanvas {
  display: block;
  width: 100%;
}

#sheetCanvas {
  max-width: 100%;
  min-height: 420px;
  margin: 0 auto;
  cursor: crosshair;
  touch-action: none;
}

.canvas-empty {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  text-align: center;
  gap: 8px;
  padding: 32px;
  color: var(--muted);
  pointer-events: none;
}

.canvas-empty[hidden] {
  display: none;
}

.canvas-empty strong {
  font-size: 1.1rem;
  color: var(--text);
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.field,
.slider-field {
  display: grid;
  gap: 8px;
}

.field-full {
  grid-column: 1 / -1;
}

.field span,
.slider-field span,
.checkbox-field span {
  font-weight: 600;
}

.field input,
.slider-field input[type="range"] {
  width: 100%;
}

input[type="number"] {
  appearance: textfield;
  border: 1px solid rgba(36, 51, 66, 0.14);
  border-radius: 14px;
  padding: 12px 14px;
  font: inherit;
  background: rgba(255, 255, 255, 0.82);
  color: var(--text);
}

input[type="range"] {
  accent-color: var(--primary);
}

.tips {
  margin-top: 18px;
  padding: 16px;
  border-radius: 18px;
  background: rgba(15, 123, 121, 0.06);
  line-height: 1.65;
}

.tips p {
  margin: 0;
}

.tips p + p {
  margin-top: 6px;
}

.preview-stage {
  overflow: hidden;
  border-radius: 22px;
  border: 1px solid rgba(36, 51, 66, 0.08);
  background:
    linear-gradient(45deg, rgba(36, 51, 66, 0.04) 25%, transparent 25%),
    linear-gradient(-45deg, rgba(36, 51, 66, 0.04) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, rgba(36, 51, 66, 0.04) 75%),
    linear-gradient(-45deg, transparent 75%, rgba(36, 51, 66, 0.04) 75%);
  background-size: 28px 28px;
  background-position: 0 0, 0 14px, 14px -14px, -14px 0;
}

#previewCanvas {
  aspect-ratio: 1;
}

.frame-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.frame-pill {
  border: 1px solid rgba(36, 51, 66, 0.12);
  border-radius: 999px;
  padding: 8px 12px;
  background: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

.frame-pill.is-active {
  background: var(--primary-soft);
  border-color: rgba(15, 123, 121, 0.28);
  color: var(--primary);
}

.checkbox-field {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  margin: 18px 0;
}

.button-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.button-row + .button-row {
  margin-top: 12px;
}

button {
  appearance: none;
  border: 1px solid rgba(36, 51, 66, 0.14);
  border-radius: 16px;
  padding: 13px 16px;
  font: inherit;
  font-weight: 700;
  color: var(--text);
  background: rgba(255, 255, 255, 0.78);
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

button:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 10px 22px rgba(36, 51, 66, 0.12);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

button.primary {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, #0f7b79, #10989d);
}

button.accent {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, #f16943, #ff8e63);
}

.export-status {
  margin: 16px 0 0;
  line-height: 1.6;
  min-height: 2.6em;
}

@media (max-width: 1120px) {
  .hero,
  .workspace {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(100vw - 18px, 100%);
    padding-top: 18px;
  }

  .panel,
  .stat-card {
    border-radius: 22px;
    padding: 18px;
  }

  .hero-stats,
  .field-grid,
  .button-row {
    grid-template-columns: 1fr;
  }

  .canvas-frame,
  #sheetCanvas {
    min-height: 320px;
  }

  .panel-heading {
    flex-direction: column;
  }

  .support-text {
    max-width: none;
  }
}