:root {
    --bg-primary: #f8fafc;
    --bg-surface: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --brand-primary: #2563eb;
    --brand-hover: #1d4ed8;
    --danger: #ef4444;
    --border-light: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
    --radius: 8px;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-sans); background-color: var(--bg-primary); color: var(--text-main); line-height: 1.6; display: flex; flex-direction: column; min-height: 100vh; }

.navbar { background-color: var(--bg-surface); border-bottom: 1px solid var(--border-light); box-shadow: var(--shadow-sm); padding: 15px 5%; display: flex; justify-content: space-between; align-items: center; }
.navbar-brand { font-size: 1.25rem; font-weight: 700; color: var(--brand-primary); text-decoration: none; }
.nav-links { display: flex; align-items: center; gap: 20px; }
.nav-links a { text-decoration: none; color: var(--text-muted); font-weight: 500; transition: color 0.2s; }
.nav-links a:hover { color: var(--brand-primary); }

.btn { padding: 8px 16px; border-radius: var(--radius); font-weight: 500; text-decoration: none; border: none; cursor: pointer; transition: all 0.2s; font-size: 0.9rem; }
.btn-primary { background-color: var(--brand-primary); color: white; }
.btn-primary:hover { background-color: var(--brand-hover); }
.btn-danger { background-color: transparent; color: var(--danger); border: 1px solid var(--danger); }
.btn-danger:hover { background-color: var(--danger); color: white; }

.container { flex: 1; width: 100%; max-width: 900px; margin: 40px auto; padding: 0 20px; }
.card { background: var(--bg-surface); border: 1px solid var(--border-light); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow-md); margin-bottom: 20px;}

.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-weight: 500; margin-bottom: 8px; font-size: 0.9rem; }
.form-control { width: 100%; padding: 10px; border: 1px solid var(--border-light); border-radius: var(--radius); font-family: inherit; transition: border-color 0.2s; }
.form-control:focus { outline: none; border-color: var(--brand-primary); }

footer { text-align: center; padding: 20px; color: var(--text-muted); font-size: 0.85rem; border-top: 1px solid var(--border-light); margin-top: auto; }

/* Builder Specifics */
.toolbox-item { background: var(--bg-primary); border: 1px solid var(--border-light); padding: 12px; margin-bottom: 10px; border-radius: var(--radius); cursor: grab; display: flex; align-items: center; gap: 10px; font-weight: 500; transition: border-color 0.2s; }
.toolbox-item:hover { border-color: var(--brand-primary); }
.canvas-block { background: white; border: 1px solid var(--border-light); padding: 20px; margin-bottom: 15px; border-radius: var(--radius); position: relative; box-shadow: var(--shadow-sm); }
.canvas-block:hover { border-color: var(--brand-primary); }
.block-controls { position: absolute; top: 10px; right: 10px; display: flex; gap: 5px; }
.block-btn { background: var(--bg-primary); border: 1px solid var(--border-light); border-radius: 4px; cursor: pointer; padding: 2px 6px; font-size: 0.8rem; }
.block-btn:hover { background: #e2e8f0; }
.btn-delete:hover { background: #fee2e2; color: #ef4444; border-color: #ef4444; }
.block-input { width: 100%; border: none; outline: none; font-family: inherit; background: transparent; resize: vertical; }
.block-input.heading { font-size: 1.5rem; font-weight: bold; color: var(--text-main); }
.block-input.paragraph { font-size: 1rem; color: var(--text-main); min-height: 80px; }
.block-input.image-url { border: 1px solid var(--border-light); padding: 8px; border-radius: 4px; margin-bottom: 10px; }