:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --text: #1f2430;
  --muted: #6b7280;
  --border: #e2e5ec;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --success: #16a34a;
  --success-bg: #f0fdf4;
  --radius: 12px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.wrap {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

header h1 {
  font-size: 1.6rem;
  margin-bottom: 6px;
}

.subtitle {
  color: var(--muted);
  font-size: 0.95rem;
  margin-top: 0;
}

.tabs {
  display: flex;
  gap: 8px;
  margin: 24px 0 20px;
  border-bottom: 1px solid var(--border);
}

.tab-btn {
  background: none;
  border: none;
  padding: 10px 18px;
  font-size: 1rem;
  cursor: pointer;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

.tab-panel { display: none; }
.tab-panel.active { display: block; }

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  cursor: pointer;
  background: var(--card);
  transition: border-color 0.15s ease, background 0.15s ease;
}

.dropzone:hover, .dropzone.dragover {
  border-color: var(--accent);
  background: #f5f4ff;
}

.drop-icon { font-size: 2rem; display: block; margin-bottom: 8px; }

.hint-small { color: var(--muted); font-size: 0.85rem; margin: 4px 0 0; }

.preview-img {
  max-width: 100%;
  max-height: 320px;
  border-radius: 8px;
  display: block;
  margin: 0 auto;
}

.file-info {
  font-size: 0.85rem;
  color: var(--muted);
  min-height: 1.2em;
  margin: 6px 2px 0;
}

.field-label {
  display: block;
  font-weight: 600;
  margin: 18px 0 6px;
  font-size: 0.92rem;
}

textarea, input[type="password"], input[type="text"] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  background: var(--card);
  color: var(--text);
}

textarea { resize: vertical; }

.password-row {
  display: flex;
  gap: 8px;
}

.password-row input { flex: 1; }

.toggle-pw {
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: 8px;
  cursor: pointer;
  padding: 0 14px;
  font-size: 1rem;
}

.primary-btn {
  display: inline-block;
  width: 100%;
  margin-top: 20px;
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  box-sizing: border-box;
}

.primary-btn:hover { background: var(--accent-hover); }
.primary-btn:disabled { opacity: 0.6; cursor: not-allowed; }

.secondary-btn {
  margin-top: 10px;
  padding: 8px 14px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
}

.status {
  min-height: 1.4em;
  margin-top: 12px;
  font-size: 0.92rem;
}

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

.result-box {
  margin-top: 20px;
  padding: 16px;
  background: var(--success-bg);
  border: 1px solid #bbf7d0;
  border-radius: var(--radius);
}

.result-box p { margin-top: 0; font-weight: 600; }

.download-btn { margin-top: 14px; }

#reveal-result-text {
  background: #fff;
}

footer {
  margin-top: 40px;
  font-size: 0.82rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

footer .warn {
  color: #92400e;
  background: #fffbeb;
  border: 1px solid #fde68a;
  padding: 10px 12px;
  border-radius: 8px;
  margin-top: 10px;
}