diff --git a/internal/archdocs/pssg/render/funcs.go b/internal/archdocs/pssg/render/funcs.go
index 6029636..631de85 100644
--- a/internal/archdocs/pssg/render/funcs.go
+++ b/internal/archdocs/pssg/render/funcs.go
@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"reflect"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -141,7 +142,8 @@ func formatNumber(n interface{}) string {
 
 var isoDuration = regexp.MustCompile(`PT(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?`)
 
-// durationMinutes converts an ISO 8601 duration to minutes.
+// durationMinutes converts an ISO 8601 duration to minutes, truncating any
+// remaining seconds.
 func durationMinutes(d string) int {
 	matches := isoDuration.FindStringSubmatch(d)
 	if matches == nil {
@@ -149,7 +151,8 @@ func durationMinutes(d string) int {
 	}
 	hours, _ := strconv.Atoi(matches[1])
 	minutes, _ := strconv.Atoi(matches[2])
-	return hours*60 + minutes
+	seconds, _ := strconv.Atoi(matches[3])
+	return hours*60 + minutes + seconds/60
 }
 
 // totalTime adds two ISO 8601 durations.
@@ -237,32 +240,30 @@ func dict(values ...interface{}) map[string]interface{} {
 	return result
 }
 
+func clampSliceBounds(start, end, length int) (int, int) {
+	if start < 0 {
+		start = 0
+	}
+	if end > length {
+		end = length
+	}
+	if start > end {
+		start = end
+	}
+	return start, end
+}
+
 func sliceHelper(items interface{}, start, end int) interface{} {
 	switch v := items.(type) {
 	case []string:
-		if start < 0 {
-			start = 0
-		}
-		if end > len(v) {
-			end = len(v)
-		}
-		return v[start:end]
+		s, e := clampSliceBounds(start, end, len(v))
+		return v[s:e]
 	case []*entity.Entity:
-		if start < 0 {
-			start = 0
-		}
-		if end > len(v) {
-			end = len(v)
-		}
-		return v[start:end]
+		s, e := clampSliceBounds(start, end, len(v))
+		return v[s:e]
 	case []interface{}:
-		if start < 0 {
-			start = 0
-		}
-		if end > len(v) {
-			end = len(v)
-		}
-		return v[start:end]
+		s, e := clampSliceBounds(start, end, len(v))
+		return v[s:e]
 	}
 	return items
 }
@@ -282,6 +283,7 @@ func length(v interface{}) int {
 func sortStrings(s []string) []string {
 	result := make([]string, len(s))
 	copy(result, s)
+	sort.Strings(result)
 	return result
 }
 
diff --git a/internal/archdocs/pssg/render/funcs_test.go b/internal/archdocs/pssg/render/funcs_test.go
new file mode 100644
index 0000000..cd08927
--- /dev/null
+++ b/internal/archdocs/pssg/render/funcs_test.go
@@ -0,0 +1,69 @@
+package render
+
+import (
+	"testing"
+)
+
+func TestDurationMinutes(t *testing.T) {
+	cases := []struct {
+		input string
+		want  int
+	}{
+		{"PT30M", 30},
+		{"PT1H", 60},
+		{"PT1H30M", 90},
+		{"PT90S", 1},        // 90 seconds → 1 minute (truncated)
+		{"PT30S", 0},        // 30 seconds → 0 minutes (truncated)
+		{"PT2H30M45S", 150}, // seconds truncated
+		{"PT10M30S", 10},    // 10 min 30 sec → 10 min
+		{"PT0S", 0},
+		{"", 0},
+		{"invalid", 0},
+	}
+	for _, c := range cases {
+		got := durationMinutes(c.input)
+		if got != c.want {
+			t.Errorf("durationMinutes(%q) = %d, want %d", c.input, got, c.want)
+		}
+	}
+}
+
+func TestSliceHelper(t *testing.T) {
+	s := []string{"a", "b", "c"}
+
+	// Normal case
+	got := sliceHelper(s, 0, 2).([]string)
+	if len(got) != 2 || got[0] != "a" || got[1] != "b" {
+		t.Errorf("sliceHelper normal: got %v", got)
+	}
+
+	// start > len(v) — must not panic, return empty
+	got = sliceHelper(s, 5, 10).([]string)
+	if len(got) != 0 {
+		t.Errorf("sliceHelper start>len: want empty, got %v", got)
+	}
+
+	// start > end after clamping — must not panic
+	got = sliceHelper(s, 2, 1).([]string)
+	if len(got) != 0 {
+		t.Errorf("sliceHelper start>end: want empty, got %v", got)
+	}
+
+	// negative start
+	got = sliceHelper(s, -1, 2).([]string)
+	if len(got) != 2 {
+		t.Errorf("sliceHelper negative start: got %v", got)
+	}
+}
+
+func TestSortStrings(t *testing.T) {
+	input := []string{"c", "a", "b"}
+	got := sortStrings(input)
+	if got[0] != "a" || got[1] != "b" || got[2] != "c" {
+		t.Errorf("sortStrings: got %v, want [a b c]", got)
+	}
+	// Original must not be modified
+	if input[0] != "c" {
+		t.Errorf("sortStrings modified original slice")
+	}
+}