:root {
  --bg: #ffffff;
  --fg: #1a1d23;
  --muted: #5b6270;
  --border: #e2e5ea;
  --accent: #2f6fed;
  --accent-fg: #ffffff;
  --highlight: #ffe08a;
  --surface: #f6f7f9;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --fg: #e9ebef;
    --muted: #9aa1ad;
    --border: #2a2d34;
    --accent: #6d9dff;
    --accent-fg: #0c1220;
    --highlight: #7a5b00;
    --surface: #1b1e24;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
}

.wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--fg);
  text-decoration: none;
}
.brand .tagline {
  font-weight: 400;
  font-size: 0.75rem;
  color: var(--muted);
  margin-left: 6px;
  vertical-align: middle;
}
.site-header nav a {
  margin-left: 18px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}
.site-header nav a:hover { color: var(--accent); }
.lang-switch {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
}

main.wrap { padding: 36px 20px 60px; }

h1 { font-size: 1.8rem; margin: 0 0 8px; }
h2 { font-size: 1.25rem; margin: 32px 0 12px; }
p.intro { color: var(--muted); max-width: 60ch; }

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}
.tool-card {
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  text-decoration: none;
  color: var(--fg);
  background: var(--surface);
  transition: border-color .15s ease;
}
.tool-card:hover { border-color: var(--accent); }
.tool-card .icon { font-size: 1.6rem; }
.tool-card h3 { margin: 10px 0 6px; font-size: 1.05rem; }
.tool-card p { margin: 0; color: var(--muted); font-size: 0.9rem; }

textarea.dwf-input {
  width: 100%;
  min-height: 220px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--fg);
  font-size: 1rem;
  font-family: inherit;
  resize: vertical;
}

.dwf-options {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  align-items: center;
  margin: 14px 0;
  font-size: 0.9rem;
  color: var(--muted);
}
.dwf-options label { display: flex; align-items: center; gap: 6px; }
.dwf-options input[type="number"] {
  width: 56px;
  padding: 3px 6px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--fg);
}

.dwf-actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 14px 0 28px; }
button, .btn {
  border: none;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 0.95rem;
  cursor: pointer;
  background: var(--accent);
  color: var(--accent-fg);
}
button.secondary {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
}
button:disabled { opacity: .5; cursor: default; }

.dwf-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
  margin: 20px 0;
}
.dwf-stats .stat {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  background: var(--surface);
}
.dwf-stats .stat .value { font-size: 1.4rem; font-weight: 700; }
.dwf-stats .stat .label { font-size: 0.8rem; color: var(--muted); }

.dwf-result {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  background: var(--surface);
  white-space: pre-wrap;
  word-wrap: break-word;
  min-height: 60px;
}
.dwf-result mark {
  background: var(--highlight);
  color: inherit;
  border-radius: 3px;
  padding: 0 1px;
}

table.dwf-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 28px;
  font-size: 0.92rem;
}
table.dwf-table th, table.dwf-table td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
}
table.dwf-table th { color: var(--muted); font-weight: 600; }

.faq dt { font-weight: 600; margin-top: 14px; }
.faq dd { margin: 4px 0 0; color: var(--muted); }

.feedback-form {
  display: grid;
  gap: 10px;
  max-width: 480px;
  margin-top: 12px;
}
.feedback-form input, .feedback-form textarea {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--fg);
  font-family: inherit;
  font-size: 0.95rem;
}
.feedback-form textarea { min-height: 100px; resize: vertical; }
.feedback-status { font-size: 0.88rem; margin-top: 4px; }
.feedback-status.ok { color: #2e8b57; }
.feedback-status.err { color: #c0392b; }

.upload-form { margin: 20px 0; }
.upload-drop {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 32px 20px;
  cursor: pointer;
  background: var(--surface);
  color: var(--muted);
}
.upload-drop:hover { border-color: var(--accent); color: var(--fg); }
.upload-icon { font-size: 1.8rem; }
.upload-drop input[type="file"] { margin-top: 8px; max-width: 100%; }
.privacy-note { font-size: 0.85rem; color: var(--muted); margin-top: 8px; }
.form-error {
  background: color-mix(in srgb, #c0392b 12%, transparent);
  border: 1px solid #c0392b;
  color: #c0392b;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.9rem;
}

.doc-page {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px clamp(20px, 6vw, 64px);
  margin: 20px 0 32px;
  box-shadow: 0 1px 3px rgba(0,0,0,.06);
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.7;
}
.doc-page p { position: relative; margin: 0 0 1em; }
.doc-page .doc-heading { font-family: inherit; margin: 1.2em 0 0.6em; }
.doc-page .doc-para-num {
  display: block;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--muted);
  margin-bottom: 2px;
}
.doc-page mark.repeat {
  background: transparent;
  color: inherit;
  border-bottom: 2px solid #e0a800;
  background: color-mix(in srgb, #ffe08a 35%, transparent);
  padding: 0 1px;
  border-radius: 2px;
  cursor: help;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 20px 0 40px;
  color: var(--muted);
  font-size: 0.85rem;
}
.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}
.site-footer nav a { color: var(--muted); margin-left: 14px; }