:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --border: #dde1e6;
  --text: #1b1f24;
  --muted: #5b6472;
  --accent: #2f6fed;
  --accent-hover: #2559c4;
  --success: #157347;
  --error: #b00020;
  --mono: "Menlo", "SF Mono", Consolas, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.login-body {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.login-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  width: 320px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}

.login-card h1 { margin: 0; font-size: 20px; }
.subtitle { margin: 0; color: var(--muted); font-size: 14px; }
.error { color: var(--error); font-size: 14px; margin: 0; }

.login-card input {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}

.login-card button, .primary-btn {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 14px;
  cursor: pointer;
}

.login-card button:hover, .primary-btn:hover { background: var(--accent-hover); }

.app-body {
  display: flex;
  min-height: 100vh;
}

.sidenav {
  width: 220px;
  flex-shrink: 0;
  background: var(--card);
  border-right: 1px solid var(--border);
  padding: 20px 16px;
  display: flex;
  flex-direction: column;
}

.sidenav .brand {
  font-weight: 600;
  margin-bottom: 20px;
  padding: 0 4px;
}

.sidenav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1;
}

.sidenav a {
  display: block;
  padding: 9px 10px;
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
  margin-bottom: 2px;
}

.sidenav a:hover { background: var(--bg); }
.sidenav a.active { background: var(--accent); color: white; }

.logout-form { padding: 0 4px; }

.link-btn {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 14px;
  padding: 0;
}

.tool-card {
  flex: 1;
  max-width: 780px;
  margin: 32px auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  align-self: flex-start;
}

.tool-card h1 { margin-top: 0; font-size: 20px; }

.field-label {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin: 12px 0 6px;
}

.editor-wrap {
  position: relative;
  height: 260px;
}

.editor-layer {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  margin: 0;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow: auto;
  border-radius: 8px;
  border: 1px solid var(--border);
}

#highlight-layer {
  color: transparent;
  pointer-events: none;
}

.editor-input {
  background: transparent;
  resize: none;
  color: var(--text);
  caret-color: var(--text);
}

.dup-message {
  color: var(--error);
  font-size: 13px;
  min-height: 18px;
  margin: 6px 0 0;
}

.btn-row {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

.btn-row .primary-btn { flex: 1; padding: 12px; }

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

.output-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 12px;
}

.output-box {
  width: 100%;
  height: 200px;
  font-family: var(--mono);
  font-size: 13px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  resize: vertical;
}

.tool-desc {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 10px;
  background: var(--bg);
  padding: 32px 16px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
  margin: 16px 0;
  transition: border-color 0.15s, color 0.15s;
}

.drop-zone.drag-over {
  border-color: var(--accent);
  color: var(--accent);
}

.drop-zone.has-file {
  border-style: solid;
  border-color: var(--success);
  color: var(--success);
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text);
  margin: 12px 0 20px;
}

.full-width { width: 100%; padding: 12px; }