diff --git a/packages/ludic.ui/anim.ludic b/packages/ludic.ui/anim.ludic
index 505c1d2e..8dbcf165 100644
--- a/packages/ludic.ui/anim.ludic
+++ b/packages/ludic.ui/anim.ludic
@@ -23,15 +23,23 @@ function an_read(ui_st: mut UiState, name: string, body: string, err: []string)
   while r.err == "" {
     rd_ws(r)
     if r.i >= len(r.s) { break }
-    let stop = tpl_words(lss_upto(r, 123))
-    let decls = lss_decls(lss_upto(r, 125), err)
+    let sr = lss_upto(r, 123)
+    let stop = tpl_words(sr)
+    let db = lss_upto(r, 125)
+    let decls = lss_decls(db, err)
     var at = el_num(stop) / 100.0
     if stop == "from" { at = 0.0 }
     if stop == "to" { at = 1.0 }
     push(k.stops, at)
     push(k.rules, decls)
+    unsafe {                           # the stop and its body are read, never kept
+      if not tpl_clean(sr) { free(stop) }
+      free(sr)
+      free(db)
+    }
   }
   push(ui_st.an_frames, k)
+  unsafe { free(r) }
 }
 function an_find(ui_st: UiState, name: string) -> UiKeyframes {
   for i in 0 .. len(ui_st.an_frames) {
diff --git a/packages/ludic.ui/style.ludic b/packages/ludic.ui/style.ludic
index 433a3cf4..00dcbd58 100644
--- a/packages/ludic.ui/style.ludic
+++ b/packages/ludic.ui/style.ludic
@@ -51,13 +51,17 @@ function lss_block(ui_st: mut UiState, f: UiFile, src: string, md: UiMedia, err:
       continue
     }
     if rd_op(r, "@keyframes") {
-      let name = lss_upto(r, 123)
-      an_read(ui_st, name, lss_upto(r, 125), err)
+      let name = lss_upto(r, 123)      # kept: the keyframes' name may be this very text
+      let kb = lss_upto(r, 125)
+      an_read(ui_st, name, kb, err)
+      unsafe { free(kb) }
       continue
     }
     if rd_op(r, "@media") {
       let cond = md_parse(lss_upto(r, 123))
-      lss_block(ui_st, f, lss_upto(r, 125), cond, err)
+      let mb = lss_upto(r, 125)
+      lss_block(ui_st, f, mb, cond, err)
+      unsafe { free(mb) }
       continue
     }
     let sels = lss_upto(r, 123)
@@ -65,6 +69,10 @@ function lss_block(ui_st: mut UiState, f: UiFile, src: string, md: UiMedia, err:
     let at = len(f.own)
     lss_rule(f, sels, body, err)
     for i in at .. len(f.own) { f.own[i].md = md }
+    unsafe {                           # a rule keeps what it parsed, never the text it was sliced from
+      free(sels)
+      free(body)
+    }
   }
   if r.err != "" { push(err, r.err) }
   unsafe { free(r) }                   # the reader only: its text is the caller's
@@ -95,20 +103,25 @@ function lss_upto(r: UiRd, c: int) -> string {
 }
 function lss_strip(src: string) -> string {
   if not lss_has_comment(src) { return src }     # no comment: nothing to strip, nothing made
-  var out = ""
-  var at = 0
+  # written once into bytes of its own (lss_text frees them): joined a piece at a time, every
+  # comment left the text so far behind
+  var p: pointer = null
+  unsafe { p = bytes(len(src) + 1) }
+  var n = 0
   var i = 0
-  while i + 1 < len(src) {
-    if src[i] == 47 and src[i + 1] == 42 {
-      out = out + src[at..i]
+  while i < len(src) {
+    if i + 1 < len(src) and src[i] == 47 and src[i + 1] == 42 {
       var j = i + 2
       while j + 1 < len(src) and not (src[j] == 42 and src[j + 1] == 47) { j += 1 }
       i = j + 2
-      at = i
-    } else { i += 1 }
+    } else {
+      unsafe { p[n] = src[i] }
+      n += 1
+      i += 1
+    }
   }
-  if at < len(src) { out = out + src[at..len(src)] }
-  return out
+  unsafe { p[n] = 0 }
+  return p
 }
 function lss_has_comment(src: string) -> bool {
   for i in 0 .. len(src) - 1 {
diff --git a/packages/ludic.ui/style_rule.ludic b/packages/ludic.ui/style_rule.ludic
index 45c30e18..4243927c 100644
--- a/packages/ludic.ui/style_rule.ludic
+++ b/packages/ludic.ui/style_rule.ludic
@@ -4,16 +4,23 @@ function lss_rule(f: UiFile, sels: string, body: string, err: []string) -> void
   let each = lss_split(sels, 44)
   for i in 0 .. len(each) {
     let sel = tpl_words(each[i])
-    if len(sel) == 0 { continue }
-    let r = new UiRule
-    r.keys = decls.keys
-    r.vals = decls.vals
-    r.sel = sel_parse(sel, err)
-    if r.sel != null {
-      r.spec = sel_spec(r.sel)
-      push(f.own, r)
+    if len(sel) > 0 { lss_rule_add(f, decls, sel, err) }
+    unsafe {                           # a selector keeps its parsed parts, never its text
+      if not tpl_clean(each[i]) { free(sel) }
+      free(each[i])
     }
   }
+  unsafe { free(each) }
+}
+function lss_rule_add(f: UiFile, decls: UiRule, sel: string, err: []string) -> void {
+  let r = new UiRule
+  r.keys = decls.keys
+  r.vals = decls.vals
+  r.sel = sel_parse(sel, err)
+  if r.sel != null {
+    r.spec = sel_spec(r.sel)
+    push(f.own, r)
+  }
 }
 # `key: value; key: value`, a rule's body or a style="..." attribute
 function lss_decls(body: string, err: []string) -> UiRule {
@@ -31,8 +38,11 @@ function lss_decls(body: string, err: []string) -> UiRule {
       if len(tpl_words(d)) > 0 { push(err, `"{tpl_words(d)}" is not a property: value`) }
       continue
     }
-    push(r.keys, tpl_words(d[0..colon]))
-    push(r.vals, tpl_value(tpl_words(d[colon + 1..len(d)]), err))
+    lss_decl_add(r, d, colon, err)
+  }
+  unsafe {                             # the pieces the declarations were sliced from
+    for i in 0 .. len(decls) { free(decls[i]) }
+    free(decls)
   }
   return r
 }
@@ -70,3 +80,18 @@ function sheet_add(sh: UiSheet, r: UiRule) -> void {
   }
   sh.rules[i] = r
 }
+
+# one `key: value` into the rule: the key kept as read (a clean slice is its own words), the
+# value parsed (its expression copies what it keeps), and the slices nothing keeps given back
+function lss_decl_add(r: UiRule, d: string, colon: int, err: []string) -> void {
+  let kr: string = d[0..colon]
+  push(r.keys, tpl_words(kr))
+  if not tpl_clean(kr) { unsafe { free(kr) } }
+  let vr: string = d[colon + 1..len(d)]
+  let vt = tpl_words(vr)
+  push(r.vals, tpl_value(vt, err))
+  unsafe {
+    if not tpl_clean(vr) { free(vt) }
+    free(vr)
+  }
+}