:root {
  color-scheme: light;
  --bg: #f4f7fb;
  --card: #ffffff;
  --text: #172033;
  --muted: #64748b;
  --line: #dbe3ef;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  --radius: 20px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  background: radial-gradient(circle at top left, #e0edff 0, transparent 36rem), var(--bg);
  color: var(--text);
}

code {
  padding: 0.1rem 0.35rem;
  border-radius: 0.35rem;
  background: #edf2ff;
  color: #1e40af;
}

button,
select,
input {
  font: inherit;
}

button,
.file-button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--text);
  border-radius: 12px;
  padding: 0.72rem 1rem;
  cursor: pointer;
  transition: 0.16s ease;
  white-space: nowrap;
}

button:hover,
.file-button:hover {
  transform: translateY(-1px);
  border-color: #9bb8f3;
  box-shadow: 0 10px 22px rgba(37, 99, 235, 0.12);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.48;
  transform: none;
  box-shadow: none;
}

button.primary {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
}

button.primary:hover {
  background: var(--primary-dark);
}

select {
  width: 100%;
  min-width: 11rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.72rem 0.85rem;
  background: #fff;
  color: var(--text);
}

.hero {
  max-width: 1180px;
  margin: 0 auto;
  padding: 4rem 1.25rem 2rem;
}

.eyebrow {
  margin: 0 0 0.5rem;
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0.75rem;
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1.05;
}

.subtitle {
  max-width: 780px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.75;
}

.page {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.25rem 3rem;
}

.card {
  border: 1px solid rgba(219, 227, 239, 0.9);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: var(--shadow);
}

.uploader {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 1.25rem;
  align-items: center;
  min-height: 150px;
  padding: 1.5rem;
  border-style: dashed;
}

.uploader.drag-over {
  border-color: var(--primary);
  background: #f8fbff;
}

.upload-icon {
  display: grid;
  width: 4rem;
  height: 4rem;
  place-items: center;
  border-radius: 18px;
  background: #eaf1ff;
  color: var(--primary);
  font-size: 2rem;
  font-weight: 800;
}

.upload-copy h2 {
  margin-bottom: 0.35rem;
}

.upload-copy p,
.status,
.section-head p,
.footer {
  color: var(--muted);
}

.file-button input {
  display: none;
}

.file-name {
  grid-column: 2 / -1;
  color: var(--muted);
  font-size: 0.9rem;
  overflow-wrap: anywhere;
}

.controls {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr)) auto;
  gap: 1rem;
  align-items: end;
  margin-top: 1rem;
  padding: 1.25rem;
}

.field label {
  display: block;
  margin-bottom: 0.45rem;
  color: #334155;
  font-size: 0.9rem;
  font-weight: 700;
}

.actions,
.button-row {
  display: flex;
  gap: 0.65rem;
  align-items: center;
  flex-wrap: wrap;
}

.status {
  grid-column: 1 / -1;
  margin: 0.25rem 0 0;
}

.status.error {
  color: var(--danger);
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}

.summary-card {
  padding: 1rem;
  border: 1px solid rgba(219, 227, 239, 0.9);
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 12px 26px rgba(15, 23, 42, 0.05);
}

.summary-label {
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: 0.82rem;
}

.summary-value {
  font-size: 1.35rem;
  font-weight: 800;
  overflow-wrap: anywhere;
}

.chart-card {
  margin-top: 1rem;
  padding: 1.25rem;
}

.section-head {
  display: flex;
  gap: 1rem;
  align-items: start;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.section-head h2 {
  margin-bottom: 0.35rem;
}

.section-head p {
  margin-bottom: 0;
}

.chart {
  width: 100%;
  min-height: 620px;
  border: 1px solid #eef2f7;
  border-radius: 16px;
  background: #fff;
  overflow: hidden;
}

.stacked-chart {
  min-height: 1200px;
}

.hidden {
  display: none;
}

.footer {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.25rem 2rem;
  font-size: 0.85rem;
}

@media (max-width: 820px) {
  .uploader,
  .controls,
  .section-head {
    grid-template-columns: 1fr;
  }

  .section-head {
    display: block;
  }

  .button-row {
    margin-top: 1rem;
  }

  .summary-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .file-name {
    grid-column: auto;
  }
}

@media (max-width: 520px) {
  .summary-grid {
    grid-template-columns: 1fr;
  }
}