:root {
  --bg: #f4f6fb;
  --panel: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --border: rgba(15, 23, 42, 0.16);
  --accent: #2563eb;
  --danger: #dc2626;
  --ok: #059669;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: radial-gradient(1200px 600px at 20% 0%, #ffffff 0%, var(--bg) 55%);
  color: var(--text);
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 16px 28px;
  display: grid;
  gap: 16px;
}

.header {
  display: grid;
  gap: 6px;
}

.title {
  margin: 0;
  font-size: 22px;
  letter-spacing: 0.2px;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.35;
}

.mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
}

.controls {
  display: grid;
  gap: 12px;
}

.field {
  display: grid;
  gap: 6px;
}

.field label {
  font-size: 13px;
  color: var(--muted);
}

input[type="file"],
input[type="number"],
select,
button {
  font: inherit;
}

input[type="number"],
select {
  padding: 10px 10px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #ffffff;
  color: var(--text);
  outline: none;
}

/* Drag & drop zones */
.dropzone {
  position: relative;
  border-radius: 12px;
  border: 1px dashed var(--border);
  background: #ffffff;
  padding: 12px;
  min-height: 64px;
  display: grid;
  align-content: center;
  width: 100%;
  transition: border-color 120ms ease, background-color 120ms ease;
}

.dropzone.is-dragover {
  border-color: color-mix(in srgb, var(--accent) 80%, var(--border));
  background: color-mix(in srgb, var(--accent) 8%, #ffffff);
}

.dropzone-input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.dropzone-ui {
  pointer-events: none;
  display: grid;
  gap: 3px;
}

.dropzone-title {
  font-size: 13px;
  color: var(--text);
  opacity: 0.92;
}

.dropzone-sub {
  font-size: 12px;
  color: var(--muted);
}

.fileSummary {
  min-height: 16px;
  font-size: 12px;
  color: var(--muted);
}

.hint {
  color: var(--muted);
  font-size: 12px;
}

.row {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.row-files {
  grid-template-columns: 1fr;
}

.row-actions {
  grid-template-columns: 1fr auto;
  align-items: end;
}

button {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  background: #ffffff;
  color: var(--text);
  cursor: pointer;
}

button:hover {
  border-color: color-mix(in srgb, var(--accent) 70%, var(--border));
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

#updateBtn {
  background: color-mix(in srgb, var(--accent) 14%, #ffffff);
  border-color: color-mix(in srgb, var(--accent) 60%, var(--border));
}

.export {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: max-content;
  gap: 8px;
  justify-content: end;
  align-items: center;
}

.status {
  min-height: 18px;
  font-size: 13px;
  color: var(--muted);
}

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

.status.ok {
  color: var(--ok);
}

.chartWrap {
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
  min-height: 420px;
}

canvas {
  width: 100% !important;
  height: 420px !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 980px) {
  .row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .row-actions {
    grid-template-columns: 1fr;
  }
  .export {
    justify-content: start;
  }
}