diff --git a/test/cases/all.json b/test/cases/all.json
index 303fca6..716a973 100644
--- a/test/cases/all.json
+++ b/test/cases/all.json
@@ -20,11 +20,13 @@
           "source": {
             "start": {
               "line": 2,
-              "column": 3
+              "column": 3,
+              "offset": 4
             },
             "end": {
               "line": 2,
-              "column": 13
+              "column": 14,
+              "offset": 15
             }
           },
           "prop": "color",
@@ -34,11 +36,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 1
+          "column": 2,
+          "offset": 1
         }
       },
       "selector": "a"
@@ -53,11 +57,13 @@
       "source": {
         "start": {
           "line": 4,
-          "column": 1
+          "column": 1,
+          "offset": 17
         },
         "end": {
           "line": 4,
-          "column": 25
+          "column": 26,
+          "offset": 42
         }
       },
       "params": "(max-width: 400px)",
@@ -77,11 +83,13 @@
               "source": {
                 "start": {
                   "line": 6,
-                  "column": 5
+                  "column": 5,
+                  "offset": 55
                 },
                 "end": {
                   "line": 6,
-                  "column": 19
+                  "column": 20,
+                  "offset": 70
                 }
               },
               "prop": "padding",
@@ -91,11 +99,13 @@
           "source": {
             "start": {
               "line": 5,
-              "column": 3
+              "column": 3,
+              "offset": 45
             },
             "end": {
               "line": 5,
-              "column": 7
+              "column": 8,
+              "offset": 50
             }
           },
           "selector": ".body"
@@ -117,11 +127,13 @@
           "source": {
             "start": {
               "line": 9,
-              "column": 3
+              "column": 3,
+              "offset": 80
             },
             "end": {
               "line": 9,
-              "column": 40
+              "column": 41,
+              "offset": 118
             }
           },
           "prop": "font-family",
@@ -137,11 +149,13 @@
           "source": {
             "start": {
               "line": 10,
-              "column": 3
+              "column": 3,
+              "offset": 121
             },
             "end": {
               "line": 10,
-              "column": 32
+              "column": 33,
+              "offset": 151
             }
           },
           "text": "transform: rotate(90deg)"
@@ -155,11 +169,13 @@
           "source": {
             "start": {
               "line": 11,
-              "column": 3
+              "column": 3,
+              "offset": 154
             },
             "end": {
               "line": 11,
-              "column": 19
+              "column": 20,
+              "offset": 171
             }
           },
           "prop": "background",
@@ -169,11 +185,13 @@
       "source": {
         "start": {
           "line": 8,
-          "column": 1
+          "column": 1,
+          "offset": 72
         },
         "end": {
           "line": 8,
-          "column": 5
+          "column": 6,
+          "offset": 77
         }
       },
       "selector": ".page"
@@ -193,11 +211,13 @@
           "source": {
             "start": {
               "line": 14,
-              "column": 3
+              "column": 3,
+              "offset": 182
             },
             "end": {
               "line": 14,
-              "column": 14
+              "column": 15,
+              "offset": 194
             }
           },
           "prop": "width",
@@ -218,11 +238,13 @@
               "source": {
                 "start": {
                   "line": 16,
-                  "column": 5
+                  "column": 5,
+                  "offset": 209
                 },
                 "end": {
                   "line": 16,
-                  "column": 16
+                  "column": 17,
+                  "offset": 221
                 }
               },
               "prop": "width",
@@ -232,11 +254,13 @@
           "source": {
             "start": {
               "line": 15,
-              "column": 3
+              "column": 3,
+              "offset": 197
             },
             "end": {
               "line": 15,
-              "column": 9
+              "column": 10,
+              "offset": 204
             }
           },
           "selector": "&_title"
@@ -245,11 +269,13 @@
       "source": {
         "start": {
           "line": 13,
-          "column": 1
+          "column": 1,
+          "offset": 173
         },
         "end": {
           "line": 13,
-          "column": 6
+          "column": 7,
+          "offset": 179
         }
       },
       "selector": ".phone"
@@ -275,11 +301,13 @@
               "source": {
                 "start": {
                   "line": 20,
-                  "column": 5
+                  "column": 5,
+                  "offset": 244
                 },
                 "end": {
                   "line": 20,
-                  "column": 16
+                  "column": 17,
+                  "offset": 256
                 }
               },
               "prop": "color",
@@ -294,11 +322,13 @@
               "source": {
                 "start": {
                   "line": 21,
-                  "column": 5
+                  "column": 5,
+                  "offset": 261
                 },
                 "end": {
                   "line": 21,
-                  "column": 21
+                  "column": 22,
+                  "offset": 278
                 }
               },
               "prop": "background",
@@ -308,11 +338,13 @@
           "source": {
             "start": {
               "line": 19,
-              "column": 3
+              "column": 3,
+              "offset": 231
             },
             "end": {
               "line": 19,
-              "column": 10
+              "column": 11,
+              "offset": 239
             }
           },
           "selector": "--black:"
@@ -321,24 +353,27 @@
       "source": {
         "start": {
           "line": 18,
-          "column": 1
+          "column": 1,
+          "offset": 223
         },
         "end": {
           "line": 18,
-          "column": 5
+          "column": 6,
+          "offset": 228
         }
       },
       "selector": ":root"
-    }
-  ],
+    }],
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
-      "line": 21,
-      "column": 21
+      "line": 22,
+      "column": 1,
+      "offset": 279
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/atrules.json b/test/cases/atrules.json
index 58921c3..ab0c911 100644
--- a/test/cases/atrules.json
+++ b/test/cases/atrules.json
@@ -15,11 +15,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 5
+          "column": 5,
+          "offset": 4
         }
       },
       "params": ""
@@ -34,11 +36,13 @@
       "source": {
         "start": {
           "line": 3,
-          "column": 1
+          "column": 1,
+          "offset": 7
         },
         "end": {
           "line": 3,
-          "column": 16
+          "column": 16,
+          "offset": 22
         }
       },
       "params": "\"UTF-8\""
@@ -53,11 +57,13 @@
       "source": {
         "start": {
           "line": 5,
-          "column": 1
+          "column": 1,
+          "offset": 25
         },
         "end": {
           "line": 6,
-          "column": 29
+          "column": 29,
+          "offset": 79
         }
       },
       "params": "(color: black),\n          (background: black)",
@@ -77,11 +83,13 @@
           "source": {
             "start": {
               "line": 7,
-              "column": 3
+              "column": 3,
+              "offset": 82
             },
             "end": {
               "line": 7,
-              "column": 44
+              "column": 44,
+              "offset": 123
             }
           },
           "params": "(max-width:  400px) ",
@@ -97,11 +105,13 @@
               "source": {
                 "start": {
                   "line": 8,
-                  "column": 5
+                  "column": 5,
+                  "offset": 126
                 },
                 "end": {
                   "line": 8,
-                  "column": 22
+                  "column": 22,
+                  "offset": 143
                 }
               },
               "text": "write code here"
@@ -114,11 +124,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
       "line": 8,
-      "column": 22
+      "column": 22,
+      "offset": 143
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/colons.json b/test/cases/colons.json
index f0de613..9fbcaf9 100644
--- a/test/cases/colons.json
+++ b/test/cases/colons.json
@@ -15,11 +15,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 34
+          "column": 35,
+          "offset": 34
         }
       },
       "params": ":--heading h1, h2"
@@ -45,11 +47,13 @@
               "source": {
                 "start": {
                   "line": 5,
-                  "column": 5
+                  "column": 5,
+                  "offset": 56
                 },
                 "end": {
                   "line": 5,
-                  "column": 10
+                  "column": 11,
+                  "offset": 62
                 }
               },
               "prop": "top",
@@ -64,11 +68,13 @@
               "source": {
                 "start": {
                   "line": 6,
-                  "column": 5
+                  "column": 5,
+                  "offset": 67
                 },
                 "end": {
                   "line": 6,
-                  "column": 11
+                  "column": 12,
+                  "offset": 74
                 }
               },
               "prop": "left",
@@ -78,11 +84,13 @@
           "source": {
             "start": {
               "line": 4,
-              "column": 3
+              "column": 3,
+              "offset": 44
             },
             "end": {
               "line": 4,
-              "column": 9
+              "column": 10,
+              "offset": 51
             }
           },
           "selector": "margin:"
@@ -102,11 +110,13 @@
               "source": {
                 "start": {
                   "line": 8,
-                  "column": 5
+                  "column": 5,
+                  "offset": 87
                 },
                 "end": {
                   "line": 8,
-                  "column": 14
+                  "column": 15,
+                  "offset": 97
                 }
               },
               "prop": "size",
@@ -121,11 +131,13 @@
               "source": {
                 "start": {
                   "line": 9,
-                  "column": 5
+                  "column": 5,
+                  "offset": 102
                 },
                 "end": {
                   "line": 9,
-                  "column": 15
+                  "column": 16,
+                  "offset": 113
                 }
               },
               "prop": "weight",
@@ -135,11 +147,13 @@
           "source": {
             "start": {
               "line": 7,
-              "column": 3
+              "column": 3,
+              "offset": 77
             },
             "end": {
               "line": 7,
-              "column": 7
+              "column": 8,
+              "offset": 82
             }
           },
           "selector": "font:"
@@ -148,11 +162,13 @@
       "source": {
         "start": {
           "line": 3,
-          "column": 1
+          "column": 1,
+          "offset": 36
         },
         "end": {
           "line": 3,
-          "column": 5
+          "column": 6,
+          "offset": 41
         }
       },
       "selector": ".test"
@@ -172,11 +188,13 @@
           "source": {
             "start": {
               "line": 12,
-              "column": 3
+              "column": 3,
+              "offset": 130
             },
             "end": {
               "line": 12,
-              "column": 13
+              "column": 14,
+              "offset": 141
             }
           },
           "prop": "color",
@@ -186,11 +204,13 @@
       "source": {
         "start": {
           "line": 11,
-          "column": 1
+          "column": 1,
+          "offset": 115
         },
         "end": {
           "line": 11,
-          "column": 12
+          "column": 13,
+          "offset": 127
         }
       },
       "selector": "a:--any-link"
@@ -216,11 +236,13 @@
               "source": {
                 "start": {
                   "line": 15,
-                  "column": 5
+                  "column": 5,
+                  "offset": 175
                 },
                 "end": {
                   "line": 15,
-                  "column": 15
+                  "column": 16,
+                  "offset": 186
                 }
               },
               "prop": "color",
@@ -230,11 +252,13 @@
           "source": {
             "start": {
               "line": 14,
-              "column": 3
+              "column": 3,
+              "offset": 157
             },
             "end": {
               "line": 14,
-              "column": 15
+              "column": 16,
+              "offset": 170
             }
           },
           "selector": "&.is-disabled"
@@ -243,11 +267,13 @@
       "source": {
         "start": {
           "line": 13,
-          "column": 1
+          "column": 1,
+          "offset": 142
         },
         "end": {
           "line": 13,
-          "column": 12
+          "column": 13,
+          "offset": 154
         }
       },
       "selector": "a:--any-link"
@@ -267,11 +293,13 @@
           "source": {
             "start": {
               "line": 18,
-              "column": 3
+              "column": 3,
+              "offset": 209
             },
             "end": {
               "line": 18,
-              "column": 13
+              "column": 14,
+              "offset": 220
             }
           },
           "prop": "color",
@@ -281,11 +309,13 @@
       "source": {
         "start": {
           "line": 17,
-          "column": 1
+          "column": 1,
+          "offset": 188
         },
         "end": {
           "line": 17,
-          "column": 18
+          "column": 19,
+          "offset": 206
         }
       },
       "selector": "article :--heading"
@@ -305,11 +335,13 @@
           "source": {
             "start": {
               "line": 21,
-              "column": 3
+              "column": 3,
+              "offset": 230
             },
             "end": {
               "line": 21,
-              "column": 13
+              "column": 14,
+              "offset": 241
             }
           },
           "prop": "--red",
@@ -319,11 +351,13 @@
       "source": {
         "start": {
           "line": 20,
-          "column": 1
+          "column": 1,
+          "offset": 222
         },
         "end": {
           "line": 20,
-          "column": 5
+          "column": 6,
+          "offset": 227
         }
       },
       "selector": ":root"
@@ -343,11 +377,13 @@
           "source": {
             "start": {
               "line": 24,
-              "column": 3
+              "column": 3,
+              "offset": 250
             },
             "end": {
               "line": 24,
-              "column": 19
+              "column": 20,
+              "offset": 267
             }
           },
           "prop": "color",
@@ -357,11 +393,13 @@
       "source": {
         "start": {
           "line": 23,
-          "column": 1
+          "column": 1,
+          "offset": 243
         },
         "end": {
           "line": 23,
-          "column": 4
+          "column": 5,
+          "offset": 247
         }
       },
       "selector": "body"
@@ -370,11 +408,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
-      "line": 24,
-      "column": 19
+      "line": 25,
+      "column": 1,
+      "offset": 268
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/comments.json b/test/cases/comments.json
index df54375..1b0fad2 100644
--- a/test/cases/comments.json
+++ b/test/cases/comments.json
@@ -15,11 +15,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 2,
-          "column": 10
+          "column": 10,
+          "offset": 20
         }
       },
       "text": "multi\n   line"
@@ -35,11 +37,13 @@
       "source": {
         "start": {
           "line": 3,
-          "column": 1
+          "column": 1,
+          "offset": 21
         },
         "end": {
           "line": 3,
-          "column": 9
+          "column": 9,
+          "offset": 29
         }
       },
       "text": "inline"
@@ -59,11 +63,13 @@
           "source": {
             "start": {
               "line": 5,
-              "column": 3
+              "column": 3,
+              "offset": 34
             },
             "end": {
               "line": 5,
-              "column": 14
+              "column": 14,
+              "offset": 45
             }
           },
           "prop": "color",
@@ -80,11 +86,13 @@
           "source": {
             "start": {
               "line": 5,
-              "column": 16
+              "column": 16,
+              "offset": 47
             },
             "end": {
               "line": 5,
-              "column": 22
+              "column": 25,
+              "offset": 56
             }
           },
           "text": "last"
@@ -98,11 +106,13 @@
           "source": {
             "start": {
               "line": 6,
-              "column": 3
+              "column": 3,
+              "offset": 58
             },
             "end": {
               "line": 6,
-              "column": 12
+              "column": 12,
+              "offset": 67
             }
           },
           "prop": "z-index",
@@ -112,11 +122,13 @@
       "source": {
         "start": {
           "line": 4,
-          "column": 1
+          "column": 1,
+          "offset": 30
         },
         "end": {
           "line": 4,
-          "column": 1
+          "column": 1,
+          "offset": 30
         }
       },
       "selector": "a"
@@ -132,11 +144,13 @@
       "source": {
         "start": {
           "line": 8,
-          "column": 1
+          "column": 1,
+          "offset": 68
         },
         "end": {
           "line": 8,
-          "column": 4
+          "column": 6,
+          "offset": 73
         }
       },
       "text": "a"
@@ -153,11 +167,13 @@
       "source": {
         "start": {
           "line": 9,
-          "column": 3
+          "column": 3,
+          "offset": 75
         },
         "end": {
           "line": 9,
-          "column": 17
+          "column": 21,
+          "offset": 93
         }
       },
       "text": "color: black"
@@ -166,11 +182,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
       "line": 9,
-      "column": 17
+      "column": 21,
+      "offset": 93
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/decls.json b/test/cases/decls.json
index 0c784e4..a94cb69 100644
--- a/test/cases/decls.json
+++ b/test/cases/decls.json
@@ -13,11 +13,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 12
+          "column": 13,
+          "offset": 12
         }
       },
       "prop": "color",
@@ -32,11 +34,13 @@
       "source": {
         "start": {
           "line": 3,
-          "column": 1
+          "column": 1,
+          "offset": 14
         },
         "end": {
           "line": 4,
-          "column": 41
+          "column": 42,
+          "offset": 98
         }
       },
       "prop": "background",
@@ -51,11 +55,13 @@
       "source": {
         "start": {
           "line": 6,
-          "column": 1
+          "column": 1,
+          "offset": 100
         },
         "end": {
           "line": 8,
-          "column": 16
+          "column": 17,
+          "offset": 147
         }
       },
       "prop": "box-shadow",
@@ -70,11 +76,13 @@
       "source": {
         "start": {
           "line": 10,
-          "column": 1
+          "column": 1,
+          "offset": 149
         },
         "end": {
           "line": 10,
-          "column": 19
+          "column": 20,
+          "offset": 168
         }
       },
       "prop": "$(var)-color",
@@ -84,11 +92,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
-      "line": 10,
-      "column": 19
+      "line": 11,
+      "column": 1,
+      "offset": 169
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/empty.json b/test/cases/empty.json
index 960e17e..a0a608a 100644
--- a/test/cases/empty.json
+++ b/test/cases/empty.json
@@ -15,11 +15,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 2
+          "column": 3,
+          "offset": 2
         }
       },
       "text": ""
@@ -28,11 +30,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
-      "line": 1,
-      "column": 2
+      "line": 2,
+      "column": 1,
+      "offset": 3
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/important.json b/test/cases/important.json
index 0cd71e1..6d34e64 100644
--- a/test/cases/important.json
+++ b/test/cases/important.json
@@ -14,11 +14,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 11
+          "column": 12,
+          "offset": 11
         }
       },
       "prop": "long",
@@ -35,11 +37,13 @@
       "source": {
         "start": {
           "line": 2,
-          "column": 1
+          "column": 1,
+          "offset": 23
         },
         "end": {
           "line": 2,
-          "column": 12
+          "column": 13,
+          "offset": 35
         }
       },
       "prop": "short",
@@ -50,11 +54,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
-      "line": 2,
-      "column": 22
+      "line": 3,
+      "column": 1,
+      "offset": 46
     }
   }
-}
+}
\ No newline at end of file
diff --git a/test/cases/rules.json b/test/cases/rules.json
index 0536993..4716a0d 100644
--- a/test/cases/rules.json
+++ b/test/cases/rules.json
@@ -26,11 +26,13 @@
               "source": {
                 "start": {
                   "line": 3,
-                  "column": 5
+                  "column": 5,
+                  "offset": 10
                 },
                 "end": {
                   "line": 3,
-                  "column": 16
+                  "column": 16,
+                  "offset": 21
                 }
               },
               "prop": "color",
@@ -40,11 +42,13 @@
           "source": {
             "start": {
               "line": 2,
-              "column": 3
+              "column": 3,
+              "offset": 3
             },
             "end": {
               "line": 2,
-              "column": 3
+              "column": 3,
+              "offset": 3
             }
           },
           "selector": "b"
@@ -53,11 +57,13 @@
       "source": {
         "start": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         },
         "end": {
           "line": 1,
-          "column": 1
+          "column": 1,
+          "offset": 0
         }
       },
       "selector": "a"
@@ -77,11 +83,13 @@
           "source": {
             "start": {
               "line": 7,
-              "column": 3
+              "column": 3,
+              "offset": 40
             },
             "end": {
               "line": 7,
-              "column": 14
+              "column": 14,
+              "offset": 51
             }
           },
           "prop": "color",
@@ -91,11 +99,13 @@
       "source": {
         "start": {
           "line": 5,
-          "column": 1
+          "column": 1,
+          "offset": 27
         },
         "end": {
           "line": 6,
-          "column": 1
+          "column": 1,
+          "offset": 39
         }
       },
       "selector": "a,\nb"
@@ -120,11 +130,13 @@
           "source": {
             "start": {
               "line": 11,
-              "column": 3
+              "column": 3,
+              "offset": 75
             },
             "end": {
               "line": 11,
-              "column": 14
+              "column": 14,
+              "offset": 86
             }
           },
           "prop": "color",
@@ -134,11 +146,13 @@
       "source": {
         "start": {
           "line": 9,
-          "column": 1
+          "column": 1,
+          "offset": 61
         },
         "end": {
           "line": 10,
-          "column": 2
+          "column": 2,
+          "offset": 74
         }
       },
       "selector": "a  b \nem"
@@ -158,11 +172,13 @@
           "source": {
             "start": {
               "line": 14,
-              "column": 3
+              "column": 3,
+              "offset": 100
             },
             "end": {
               "line": 14,
-              "column": 15
+              "column": 15,
+              "offset": 112
             }
           },
           "prop": "family",
@@ -172,11 +188,13 @@
       "source": {
         "start": {
           "line": 13,
-          "column": 1
+          "column": 1,
+          "offset": 87
         },
         "end": {
           "line": 13,
-          "column": 5
+          "column": 5,
+          "offset": 91
         }
       },
       "selector": "font:"
@@ -196,11 +214,13 @@
           "source": {
             "start": {
               "line": 17,
-              "column": 3
+              "column": 3,
+              "offset": 125
             },
             "end": {
               "line": 17,
-              "column": 14
+              "column": 14,
+              "offset": 136
             }
           },
           "prop": "color",
@@ -210,11 +230,13 @@
       "source": {
         "start": {
           "line": 16,
-          "column": 1
+          "column": 1,
+          "offset": 113
         },
         "end": {
           "line": 16,
-          "column": 8
+          "column": 8,
+          "offset": 120
         }
       },
       "selector": "[attr=;]"
@@ -223,11 +245,13 @@
   "source": {
     "start": {
       "line": 1,
-      "column": 1
+      "column": 1,
+      "offset": 0
     },
     "end": {
       "line": 17,
-      "column": 14
+      "column": 14,
+      "offset": 136
     }
   }
-}
+}
\ No newline at end of file