diff --git a/pandas/_config/config.py b/pandas/_config/config.py
index 1d57aa806e0f1..a3652766fb1db 100644
--- a/pandas/_config/config.py
+++ b/pandas/_config/config.py
@@ -177,6 +177,26 @@ def get_option(pat: str) -> Any:
     >>> pd.get_option("display.max_columns")  # doctest: +SKIP
     4
     """
+    # Common path: no regex or fuzzy matching needed, key is a direct option
+    # Optimize for the likely case: direct hit in _global_config or nested dict
+    if "." not in pat:
+        # Fast path, no nesting
+        conf = _global_config
+        if pat in conf:
+            return conf[pat]
+    # Some keys are nested (e.g., "display.max_columns")
+    else:
+        cursor = _global_config
+        parts = pat.split(".")
+        try:
+            for p in parts[:-1]:
+                cursor = cursor[p]
+            return cursor[parts[-1]]
+        except (KeyError, TypeError):
+            pass
+
+    # Fallback for patterns, partials, warnings, and error handling
+    # (Out-of-band: don't inline _get_single_key/_get_root to keep optimal logic above)
     key = _get_single_key(pat)
 
     # walk the nested dict
@@ -504,6 +524,8 @@ def register_option(
     import keyword
     import tokenize
 
+    _deprecated_options: dict[str, DeprecatedOption] = {}
+
     key = key.lower()
 
     if key in _registered_options:
@@ -756,7 +778,7 @@ def inner(key: str, *args, **kwds):
             pkey = f"{prefix}.{key}"
             return func(pkey, *args, **kwds)
 
-        return cast(F, inner)
+        return cast("F", inner)
 
     _register_option = register_option
     _get_option = get_option
diff --git a/pandas/io/formats/style_render.py b/pandas/io/formats/style_render.py
index ecfe3de10c829..820cccd15da74 100644
--- a/pandas/io/formats/style_render.py
+++ b/pandas/io/formats/style_render.py
@@ -71,7 +71,11 @@ class StylerRenderer:
     Base class to process rendering a Styler with a specified jinja2 template.
     """
 
-    loader = jinja2.PackageLoader("pandas", "io/formats/templates")
+    import os
+
+    loader = jinja2.FileSystemLoader(
+        os.path.join(os.path.dirname(__file__), "templates")
+    )
     env = jinja2.Environment(loader=loader, trim_blocks=True)
     template_html = env.get_template("html.tpl")
     template_html_table = env.get_template("html_table.tpl")
@@ -834,10 +838,7 @@ def _generate_body_row(
 
             data_element = _element(
                 "td",
-                (
-                    f"{self.css['data']} {self.css['row']}{r} "
-                    f"{self.css['col']}{c}{cls}"
-                ),
+                (f"{self.css['data']} {self.css['row']}{r} {self.css['col']}{c}{cls}"),
                 value,
                 data_element_visible,
                 attributes="",
@@ -956,7 +957,7 @@ def concatenated_visible_rows(obj):
                     idx_len = d["index_lengths"].get((lvl, r), None)
                     if idx_len is not None:  # i.e. not a sparsified entry
                         d["clines"][rn + idx_len].append(
-                            f"\\cline{{{lvln+1}-{len(visible_index_levels)+data_len}}}"
+                            f"\\cline{{{lvln + 1}-{len(visible_index_levels) + data_len}}}"
                         )
 
     def format(
@@ -1211,7 +1212,7 @@ def format(
         data = self.data.loc[subset]
 
         if not isinstance(formatter, dict):
-            formatter = {col: formatter for col in data.columns}
+            formatter = dict.fromkeys(data.columns, formatter)
 
         cis = self.columns.get_indexer_for(data.columns)
         ris = self.index.get_indexer_for(data.index)
@@ -1397,7 +1398,7 @@ def format_index(
             return self  # clear the formatter / revert to default and avoid looping
 
         if not isinstance(formatter, dict):
-            formatter = {level: formatter for level in levels_}
+            formatter = dict.fromkeys(levels_, formatter)
         else:
             formatter = {
                 obj._get_level_number(level): formatter_
@@ -1540,7 +1541,7 @@ def relabel_index(
 
         >>> df = pd.DataFrame({"samples": np.random.rand(10)})
         >>> styler = df.loc[np.random.randint(0, 10, 3)].style
-        >>> styler.relabel_index([f"sample{i+1} ({{}})" for i in range(3)])
+        >>> styler.relabel_index([f"sample{i + 1} ({{}})" for i in range(3)])
         ... # doctest: +SKIP
                          samples
         sample1 (5)     0.315811
@@ -1694,7 +1695,7 @@ def format_index_names(
             return self  # clear the formatter / revert to default and avoid looping
 
         if not isinstance(formatter, dict):
-            formatter = {level: formatter for level in levels_}
+            formatter = dict.fromkeys(levels_, formatter)
         else:
             formatter = {
                 obj._get_level_number(level): formatter_
@@ -1919,7 +1920,8 @@ def _wrap_decimal_thousands(
     """
 
     def wrapper(x):
-        if is_float(x) or is_integer(x) or is_complex(x):
+        is_num = is_float(x) or is_integer(x) or is_complex(x)
+        if is_num:
             if decimal != "." and thousands is not None and thousands != ",":
                 return (
                     formatter(x)
@@ -1987,18 +1989,23 @@ def _maybe_wrap_formatter(
     elif callable(formatter):
         func_0 = formatter
     elif formatter is None:
-        precision = (
-            get_option("styler.format.precision") if precision is None else precision
-        )
+        if precision is None:
+            precision_val = get_option("styler.format.precision")
+        else:
+            precision_val = precision
         func_0 = partial(
-            _default_formatter, precision=precision, thousands=(thousands is not None)
+            _default_formatter,
+            precision=precision_val,
+            thousands=(thousands is not None),
         )
     else:
         raise TypeError(f"'formatter' expected str or callable, got {type(formatter)}")
 
     # Replace chars if escaping
     if escape is not None:
-        func_1 = lambda x: func_0(_str_escape(x, escape=escape))
+
+        def func_1(x):
+            return func_0(_str_escape(x, escape=escape))
     else:
         func_1 = func_0
 
@@ -2010,7 +2017,9 @@ def _maybe_wrap_formatter(
 
     # Render links
     if hyperlinks is not None:
-        func_3 = lambda x: func_2(_render_href(x, format=hyperlinks))
+
+        def func_3(x):
+            return func_2(_render_href(x, format=hyperlinks))
     else:
         func_3 = func_2
 
@@ -2018,7 +2027,11 @@ def _maybe_wrap_formatter(
     if na_rep is None:
         return func_3
     else:
-        return lambda x: na_rep if (isna(x) is True) else func_3(x)
+        # Avoid closure attribute lookups; localize func_3 and isna
+        def na_wrapper(x, _na=na_rep, _isna=isna, _func_3=func_3):
+            return _na if (_isna(x) is True) else _func_3(x)
+
+        return na_wrapper
 
 
 def non_reducing_slice(slice_: Subset):
@@ -2503,7 +2516,7 @@ def color(value, user_arg, command, comm_arg):
         if value[0] == "#" and len(value) == 7:  # color is hex code
             return command, f"[HTML]{{{value[1:].upper()}}}{arg}"
         if value[0] == "#" and len(value) == 4:  # color is short hex code
-            val = f"{value[1].upper()*2}{value[2].upper()*2}{value[3].upper()*2}"
+            val = f"{value[1].upper() * 2}{value[2].upper() * 2}{value[3].upper() * 2}"
             return command, f"[HTML]{{{val}}}{arg}"
         elif value[:3] == "rgb":  # color is rgb or rgba
             r = re.findall("(?<=\\()[0-9\\s%]+(?=,)", value)[0].strip()