:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eff6ff;
  --danger-bg: #fef2f2;
  --danger: #b91c1c;
  --code-bg: #f8fafc;
  --warn-bg: #fffbeb;
  --warn-border: #fcd34d;
  --radius: 12px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --surface: #111827;
    --text: #e5e7eb;
    --muted: #94a3b8;
    --border: #1f2937;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --accent-soft: #172554;
    --danger-bg: #2a1215;
    --danger: #fca5a5;
    --code-bg: #0f172a;
    --warn-bg: #2a2110;
    --warn-border: #854d0e;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

a { color: var(--accent); }

.container { max-width: 960px; margin: 0 auto; padding: 0 16px; }

.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 60px; flex-wrap: wrap; }
.brand { font-weight: 700; color: var(--text); text-decoration: none; letter-spacing: -0.01em; }
.brand-mark { color: var(--accent); }
.nav { display: flex; gap: 4px; }
.nav-link { color: var(--muted); text-decoration: none; padding: 6px 12px; border-radius: 8px; font-weight: 500; }
.nav-link:hover { color: var(--text); }
.nav-link.active { background: var(--accent-soft); color: var(--accent); }

.hero { padding: 32px 0 16px; }
.hero h1 { margin: 0 0 6px; font-size: clamp(1.5rem, 4vw, 2rem); letter-spacing: -0.02em; }
.lede { margin: 0; color: var(--muted); }
.filename { color: var(--accent); word-break: break-all; }

.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin-bottom: 16px; }

.form { display: grid; gap: 16px; }
.form-row { display: flex; align-items: end; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.field { display: grid; gap: 6px; }
.field-inline { min-width: 220px; }
.label { font-size: 0.875rem; font-weight: 600; }
.muted { color: var(--muted); font-size: 0.9rem; }

.select, .code {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--code-bg);
  color: var(--text);
  font: inherit;
  padding: 8px 10px;
}
.code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.85rem; resize: vertical; word-break: break-all; }

.dropzone {
  position: relative;
  display: grid;
  place-items: center;
  gap: 4px;
  text-align: center;
  padding: 36px 16px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.dropzone:hover, .dropzone.dragging { border-color: var(--accent); background: var(--accent-soft); }
.dropzone-text { display: grid; gap: 2px; }
.file-input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.file-name { font-weight: 600; color: var(--accent); word-break: break-all; }

.button {
  appearance: none;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  padding: 9px 18px;
  border-radius: 8px;
  cursor: pointer;
}
.button:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.button-secondary { background: transparent; color: var(--accent); }
.button-secondary:hover { background: var(--accent-soft); }

.alert { background: var(--danger-bg); color: var(--danger); border-radius: 8px; padding: 10px 14px; margin-bottom: 16px; font-weight: 500; }

.form-options { display: flex; align-items: end; gap: 16px; flex-wrap: wrap; }
.checkbox { display: flex; align-items: center; gap: 8px; padding-bottom: 9px; font-weight: 500; cursor: pointer; }
.checkbox input { width: 18px; height: 18px; accent-color: var(--accent); }

.issue { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; background: var(--warn-bg); border-color: var(--warn-border); }
.issue h2 { margin: 0 0 4px; font-size: 1.05rem; }
.issue p { margin: 0; color: var(--text); }
.issue form { margin: 0; }

.map { height: 420px; border-radius: 8px; border: 1px solid var(--border); z-index: 0; }
.stats { margin: 0 0 12px; }

.result h2 { margin: 0; font-size: 1.1rem; }
.result p { margin: 2px 0 0; }
.result-head { display: flex; justify-content: space-between; align-items: start; gap: 12px; margin-bottom: 12px; flex-wrap: wrap; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; }
.actions form { margin: 0; }

.site-footer { color: var(--muted); font-size: 0.85rem; padding: 24px 16px 40px; }

@media (max-width: 600px) {
  .map { height: 320px; }
  .form-row .button { width: 100%; }
}

.prose { padding: 8px 4px 16px; max-width: 70ch; }
.prose h2 { font-size: 1.25rem; margin: 28px 0 8px; letter-spacing: -0.01em; }
.prose h3 { font-size: 1rem; margin: 20px 0 4px; }
.prose p, .prose li { color: var(--text); }
.prose ol { padding-left: 1.25rem; }
.prose li { margin-bottom: 6px; }
.prose code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.85em; background: var(--code-bg); border: 1px solid var(--border); border-radius: 4px; padding: 1px 4px; }

.site-footer p { margin: 0 0 6px; }
.tip { font-weight: 500; color: var(--text); }