:root {
  --bg: #0e1116;
  --bg-elev: #161b22;
  --bg-elev-2: #1f2530;
  --border: #2a3140;
  --text: #e6edf3;
  --text-dim: #8b98a8;
  --accent: #4c9aff;
  --accent-hover: #357de0;
  --ok: #2ea043;
  --warn: #d29922;
  --err: #f85149;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.5;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-elev);
}

.brand h1 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
}

.subtitle {
  margin: 0.25rem 0 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.lang-switch {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.lang-switch button {
  background: transparent;
  color: var(--text-dim);
  border: 0;
  padding: 0.4rem 0.75rem;
  font: inherit;
  cursor: pointer;
  font-size: 0.85rem;
}

.lang-switch button.active {
  background: var(--accent);
  color: white;
}

main {
  flex: 1;
  max-width: 780px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

main > section {
  margin-bottom: 1.75rem;
}

h2 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 0.75rem;
  color: var(--text);
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 2.5rem 1.5rem;
  text-align: center;
  background: var(--bg-elev);
  transition: border-color 0.15s, background 0.15s;
}

.drop-zone.dragover {
  border-color: var(--accent);
  background: var(--bg-elev-2);
}

.drop-primary {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  font-weight: 500;
}

.drop-secondary {
  margin: 0.25rem 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.drop-note {
  margin: 1rem 0 0;
  color: var(--text-dim);
  font-size: 0.8rem;
}

.btn {
  display: inline-block;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font: inherit;
  font-size: 0.9rem;
  text-align: center;
}

.btn:hover:not(:disabled) {
  border-color: var(--accent);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
  font-weight: 500;
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.file-info {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  font-size: 0.9rem;
  display: grid;
  gap: 0.35rem;
}

.file-info strong {
  color: var(--text-dim);
  font-weight: 500;
  display: inline-block;
  min-width: 90px;
}

.algo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.algo-grid label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9rem;
  user-select: none;
}

.algo-grid label:has(input:checked) {
  border-color: var(--accent);
  background: var(--bg-elev-2);
}

.progress {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
}

.progress-bar {
  height: 8px;
  background: var(--bg);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 0.5rem;
}

#progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.1s linear;
}

.progress-text {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.results h2 { margin-bottom: 0.75rem; }

.result-item {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  margin-bottom: 0.5rem;
}

.result-algo {
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 0.35rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.result-hash {
  font-family: var(--mono);
  font-size: 0.85rem;
  word-break: break-all;
  user-select: all;
  color: var(--text);
}

.copy-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  font: inherit;
  font-size: 0.75rem;
  cursor: pointer;
}

.copy-btn:hover { color: var(--text); border-color: var(--accent); }
.copy-btn.copied { color: var(--ok); border-color: var(--ok); }

.compare .hint {
  margin: 0 0 0.75rem;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.compare-row {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

#expected-hash {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.6rem 0.75rem;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 0.9rem;
  width: 100%;
}

#expected-hash:focus {
  outline: none;
  border-color: var(--accent);
}

.compare-result {
  font-size: 0.9rem;
  min-height: 1.4rem;
  font-weight: 500;
}

.compare-result.match { color: var(--ok); }
.compare-result.nomatch { color: var(--err); }
.compare-result.partial { color: var(--warn); }

.about {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
}

.about summary {
  cursor: pointer;
  color: var(--text-dim);
  font-weight: 500;
}

.about summary:hover { color: var(--text); }

.about ul { padding-left: 1.25rem; }
.about code {
  background: var(--bg);
  padding: 0.1rem 0.35rem;
  border-radius: 3px;
  font-family: var(--mono);
  font-size: 0.85em;
}

footer {
  border-top: 1px solid var(--border);
  padding: 1rem 2rem;
  color: var(--text-dim);
  font-size: 0.8rem;
  text-align: center;
  background: var(--bg-elev);
}

footer a { color: var(--accent); text-decoration: none; }
footer a:hover { text-decoration: underline; }

.hidden { display: none !important; }

@media (max-width: 600px) {
  header { padding: 1rem; flex-direction: column; align-items: stretch; }
  main { padding: 1.5rem 1rem 3rem; }
  .drop-zone { padding: 1.75rem 1rem; }
}