:root {
  --bg: #f5f6f8;
  --card-bg: #ffffff;
  --border: #dde1e6;
  --text: #1c1f24;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --success: #16a34a;
  --danger: #dc2626;
}

* { box-sizing: border-box; }

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

.hidden { display: none !important; }

/* Login */
.centered-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

#login-form {
  width: 320px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

#login-form h1 { margin: 0; }
.subtitle { color: var(--muted); margin-top: -8px; }

label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; color: var(--muted); }

input[type="text"], input[type="password"], select {
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
}

.error-text { color: var(--danger); font-size: 13px; min-height: 16px; }

button { cursor: pointer; font: inherit; }

.primary-btn {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  text-align: center;
}
.primary-btn:hover { background: var(--accent-hover); }
.primary-btn.success { background: var(--success); }

.ghost-btn {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 14px;
  color: var(--text);
}
.ghost-btn:hover { background: #eef0f3; }

.link-btn {
  background: none;
  border: none;
  color: var(--accent);
  text-decoration: underline;
  padding: 0;
  font-size: inherit;
}

/* App shell */
.topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 14px 24px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; font-size: 18px; }
.tabs { display: flex; gap: 4px; flex: 1; }
.tab-btn {
  background: none;
  border: none;
  padding: 8px 14px;
  border-radius: 8px;
  color: var(--muted);
  font-weight: 500;
}
.tab-btn.active { background: #eef2ff; color: var(--accent); }

.tab-panel { display: none; padding: 24px; max-width: 960px; margin: 0 auto; }
.tab-panel.active { display: block; }

/* Upload */
.dropzone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 60px 20px;
  text-align: center;
  background: var(--card-bg);
}
.dropzone.dragover { border-color: var(--accent); background: #eef2ff; }
.hint { color: var(--muted); font-size: 13px; }

/* Workspace */
.workspace-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.page-nav { display: flex; align-items: center; gap: 10px; }
.toolbar-actions { display: flex; gap: 10px; }

.page-container {
  position: relative;
  display: inline-block;
  background: white;
  border: 1px solid var(--border);
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
#pdf-canvas { display: block; }
#overlay-layer { position: absolute; top: 0; left: 0; right: 0; bottom: 0; }

.sig-box {
  position: absolute;
  border: 1.5px dashed var(--accent);
  background: rgba(37, 99, 235, 0.05);
  cursor: move;
}
.sig-box img { width: 100%; height: 100%; object-fit: contain; pointer-events: none; }
.sig-box .resize-handle {
  position: absolute;
  width: 12px;
  height: 12px;
  right: -6px;
  bottom: -6px;
  background: var(--accent);
  border-radius: 50%;
  cursor: nwse-resize;
}
.sig-box .delete-handle {
  position: absolute;
  top: -10px;
  right: -10px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--danger);
  color: white;
  border: none;
  font-size: 12px;
  line-height: 20px;
  padding: 0;
}

.result-card { margin-top: 20px; text-align: center; }
.result-card .primary-btn { margin: 12px 8px; }

/* History */
.doc-table { width: 100%; border-collapse: collapse; background: var(--card-bg); border-radius: 10px; overflow: hidden; }
.doc-table th, .doc-table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); font-size: 14px; }
.doc-table th { color: var(--muted); font-weight: 600; background: #fafbfc; }
.doc-table code { font-size: 11px; color: var(--muted); }

/* Verify */
.verify-result { margin-top: 16px; padding: 14px; border-radius: 8px; font-size: 14px; }
.verify-result.match { background: #ecfdf5; border: 1px solid #a7f3d0; }
.verify-result.no-match { background: #fef2f2; border: 1px solid #fecaca; }

/* Modal */
.modal {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
}
.modal-content { width: 460px; display: flex; flex-direction: column; gap: 14px; }
.sig-tabs { display: flex; gap: 6px; }
.sig-tab-btn { flex: 1; background: #f1f3f5; border: none; border-radius: 8px; padding: 8px; color: var(--muted); }
.sig-tab-btn.active { background: #eef2ff; color: var(--accent); font-weight: 600; }
.sig-tab-panel { display: none; flex-direction: column; gap: 10px; }
.sig-tab-panel.active { display: flex; }
.sig-canvas { width: 100%; height: 160px; border: 1px solid var(--border); border-radius: 8px; background: #fff; touch-action: none; }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; }