diff --git a/src/builtin/selector.rs b/src/builtin/selector.rs
index 4015796..dae2d00 100644
--- a/src/builtin/selector.rs
+++ b/src/builtin/selector.rs
@@ -33,7 +33,7 @@ fn simple_selectors(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<V
     }
 
     let compound = if let Some(ComplexSelectorComponent::Compound(compound)) =
-        selector.0.components[0].components.get(0).cloned()
+        selector.0.components[0].components.first().cloned()
     {
         compound
     } else {
diff --git a/src/output.rs b/src/output.rs
index e6a08c3..3eac132 100644
--- a/src/output.rs
+++ b/src/output.rs
@@ -129,8 +129,8 @@ impl Css {
                 for rule in body {
                     match rule {
                         Stmt::RuleSet { .. } => vals.extend(self.parse_stmt(rule)?),
-                        Stmt::Style(s) => vals.get_mut(0).unwrap().push_style(s),
-                        Stmt::Comment(s) => vals.get_mut(0).unwrap().push_comment(s),
+                        Stmt::Style(s) => vals.first_mut().unwrap().push_style(s),
+                        Stmt::Comment(s) => vals.first_mut().unwrap().push_comment(s),
                         Stmt::Media(m) => {
                             let MediaRule { query, body, .. } = *m;
                             vals.push(Toplevel::Media { query, body })
@@ -167,7 +167,7 @@ impl Css {
                         k @ Stmt::KeyframesRuleSet(..) => {
                             unreachable!("@keyframes ruleset {:?}", k)
                         }
-                        Stmt::Import(s) => vals.get_mut(0).unwrap().push_import(s),
+                        Stmt::Import(s) => vals.first_mut().unwrap().push_import(s),
                     };
                 }
                 vals
@@ -204,7 +204,7 @@ impl Css {
                 let mut vals = vec![Toplevel::new_keyframes_rule(selector)];
                 for rule in body {
                     match rule {
-                        Stmt::Style(s) => vals.get_mut(0).unwrap().push_style(s),
+                        Stmt::Style(s) => vals.first_mut().unwrap().push_style(s),
                         Stmt::KeyframesRuleSet(..) => vals.extend(self.parse_stmt(rule)?),
                         _ => todo!(),
                     }
@@ -221,7 +221,7 @@ impl Css {
             // this is how we print newlines between unrelated styles
             // it could probably be refactored
             if !v.is_empty() {
-                if let Some(Toplevel::MultilineComment(..)) = v.get(0) {
+                if let Some(Toplevel::MultilineComment(..)) = v.first() {
                 } else if is_first {
                     is_first = false;
                 } else {
diff --git a/src/parse/value/parse.rs b/src/parse/value/parse.rs
index 29ee79c..6a9dba1 100644
--- a/src/parse/value/parse.rs
+++ b/src/parse/value/parse.rs
@@ -105,7 +105,7 @@ impl<'a> Parser<'a> {
                         comma_separated.push(space_separated.pop().unwrap());
                     } else {
                         let mut span = space_separated
-                            .get(0)
+                            .first()
                             .ok_or(("Expected expression.", val.span))?
                             .span;
                         comma_separated.push(
diff --git a/src/selector/parse.rs b/src/selector/parse.rs
index 9c52257..cc7c001 100644
--- a/src/selector/parse.rs
+++ b/src/selector/parse.rs
@@ -561,7 +561,7 @@ fn is_simple_selector_start(c: char) -> bool {
 /// with pseudo-class syntax (`:before`, `:after`, `:first-line`, or
 /// `:first-letter`)
 fn is_fake_pseudo_element(name: &str) -> bool {
-    match name.as_bytes().get(0) {
+    match name.as_bytes().first() {
         Some(b'a') | Some(b'A') => name.to_ascii_lowercase() == "after",
         Some(b'b') | Some(b'B') => name.to_ascii_lowercase() == "before",
         Some(b'f') | Some(b'F') => match name.to_ascii_lowercase().as_str() {
diff --git a/src/selector/simple.rs b/src/selector/simple.rs
index 82ae23a..fb1c6b5 100644
--- a/src/selector/simple.rs
+++ b/src/selector/simple.rs
@@ -364,7 +364,7 @@ impl SimpleSelector {
                         };
                         complex
                             .components
-                            .get(0)
+                            .first()
                             .unwrap()
                             .as_compound()
                             .components