diff --git a/auditui/constants/__init__.py b/auditui/constants/__init__.py
index 8471512..0390cdd 100644
--- a/auditui/constants/__init__.py
+++ b/auditui/constants/__init__.py
@@ -1,278 +1,29 @@
-"""Paths, API/config values, and CSS used across the application."""
+"""Compatibility exports for constants grouped by domain modules."""
 
-from pathlib import Path
-
-AUTH_PATH = Path.home() / ".config" / "auditui" / "auth.json"
-CONFIG_PATH = Path.home() / ".config" / "auditui" / "config.json"
-CACHE_DIR = Path.home() / ".cache" / "auditui" / "books"
-DOWNLOAD_URL = "https://cde-ta-g7g.amazon.com/FionaCDEServiceEngine/FSDownloadContent"
-DEFAULT_CODEC = "LC_128_44100_stereo"
-MIN_FILE_SIZE = 1024 * 1024
-DEFAULT_CHUNK_SIZE = 8192
-
-TABLE_COLUMN_DEFS = (
-    ("Title", 4),
-    ("Author", 3),
-    ("Length", 1),
-    ("Progress", 1),
-    ("Downloaded", 1),
+from .downloads import DEFAULT_CHUNK_SIZE, DEFAULT_CODEC, DOWNLOAD_URL, MIN_FILE_SIZE
+from .library import (
+    AUTHOR_NAME_DISPLAY_LENGTH,
+    AUTHOR_NAME_MAX_LENGTH,
+    PROGRESS_COLUMN_INDEX,
 )
+from .paths import AUTH_PATH, CACHE_DIR, CONFIG_PATH
+from .playback import SEEK_SECONDS
+from .table import TABLE_COLUMN_DEFS
+from .ui import TABLE_CSS
 
-AUTHOR_NAME_MAX_LENGTH = 40
-AUTHOR_NAME_DISPLAY_LENGTH = 37
-PROGRESS_COLUMN_INDEX = 3
-SEEK_SECONDS = 30.0
 
-TABLE_CSS = """
-Screen {
-    background: #141622;
-}
-
-#top_bar {
-    background: #10131f;
-    color: #d5d9f0;
-    text-style: bold;
-    height: 1;
-    margin: 0;
-    padding: 0;
-}
-
-#top_left,
-#top_center,
-#top_right {
-    width: 1fr;
-    padding: 0 1;
-    background: #10131f;
-    margin: 0;
-}
-
-#top_left {
-    text-align: left;
-}
-
-#top_center {
-    text-align: center;
-}
-
-#top_right {
-    text-align: right;
-}
-
-DataTable {
-    width: 100%;
-    height: 1fr;
-    background: #141622;
-    color: #c7cfe8;
-    border: solid #262a3f;
-    scrollbar-size-horizontal: 0;
-}
-
-DataTable:focus {
-    border: solid #7aa2f7;
-}
-
-DataTable > .datatable--header {
-    background: #1b2033;
-    color: #b9c3e3;
-    text-style: bold;
-}
-
-DataTable > .datatable--cursor {
-    background: #232842;
-    color: #e6ebff;
-}
-
-DataTable > .datatable--odd-row {
-    background: #121422;
-}
-
-DataTable > .datatable--even-row {
-    background: #15182a;
-}
-
-Static {
-    height: 1;
-    text-align: center;
-    background: #10131f;
-    color: #c7cfe8;
-}
-
-Static#status {
-    color: #b6bfdc;
-}
-
-Static#progress_info {
-    color: #7aa2f7;
-    text-style: bold;
-    margin: 0;
-    padding: 0;
-    text-align: center;
-    width: 100%;
-}
-
-#progress_bar_container {
-    align: center middle;
-    width: 100%;
-    height: 1;
-}
-
-ProgressBar#progress_bar {
-    height: 1;
-    background: #10131f;
-    border: none;
-    margin: 0;
-    padding: 0;
-    width: 50%;
-}
-
-ProgressBar#progress_bar Bar {
-    width: 100%;
-}
-
-ProgressBar#progress_bar > .progress-bar--track {
-    background: #262a3f;
-}
-
-ProgressBar#progress_bar > .progress-bar--bar {
-    background: #8bd5ca;
-}
-
-HelpScreen,
-StatsScreen,
-FilterScreen {
-    align: center middle;
-    background: rgba(0, 0, 0, 0.7);
-}
-
-HelpScreen Static,
-StatsScreen Static,
-FilterScreen Static {
-    background: transparent;
-}
-
-StatsScreen #help_container {
-    width: auto;
-    min-width: 55;
-    max-width: 70;
-}
-
-StatsScreen #help_content {
-    align: center middle;
-    width: 100%;
-}
-
-StatsScreen .help_list {
-    width: 100%;
-}
-
-StatsScreen .help_list > ListItem {
-    background: transparent;
-    height: 1;
-}
-
-StatsScreen .help_list > ListItem:hover {
-    background: #232842;
-}
-
-StatsScreen .help_list > ListItem > Label {
-    width: 100%;
-    text-align: left;
-    padding-left: 2;
-}
-
-#help_container {
-    width: 72%;
-    max-width: 90;
-    min-width: 44;
-    height: auto;
-    max-height: 80%;
-    min-height: 14;
-    background: #181a2a;
-    border: heavy #7aa2f7;
-    padding: 1 1;
-}
-
-#help_title {
-    width: 100%;
-    height: 2;
-    text-align: center;
-    text-style: bold;
-    color: #7aa2f7;
-    content-align: center middle;
-    margin-bottom: 0;
-    border-bottom: solid #4b5165;
-}
-
-#help_content {
-    width: 100%;
-    height: auto;
-    padding: 0;
-    margin: 0 0 1 0;
-    align: center middle;
-}
-
-.help_list {
-    width: 100%;
-    height: auto;
-    background: transparent;
-    padding: 0;
-    scrollbar-size: 0 0;
-}
-
-.help_list > ListItem {
-    background: #1b1f33;
-    padding: 0 1;
-    height: 1;
-}
-
-.help_list > ListItem:hover {
-    background: #2a2f45;
-}
-
-.help_list > ListItem > Label {
-    width: 100%;
-    padding: 0;
-}
-
-#help_footer {
-    width: 100%;
-    height: 2;
-    text-align: center;
-    content-align: center middle;
-    color: #b6bfdc;
-    margin-top: 0;
-    border-top: solid #4b5165;
-}
-
-#filter_container {
-    width: 60;
-    height: auto;
-    background: #181a2a;
-    border: heavy #7aa2f7;
-    padding: 1 2;
-}
-
-#filter_title {
-    width: 100%;
-    height: 2;
-    text-align: center;
-    text-style: bold;
-    color: #7aa2f7;
-    content-align: center middle;
-    margin-bottom: 1;
-}
-
-#filter_input {
-    width: 100%;
-    margin: 1 0;
-}
-
-#filter_footer {
-    width: 100%;
-    height: 2;
-    text-align: center;
-    content-align: center middle;
-    color: #b6bfdc;
-    margin-top: 1;
-}
-"""
+__all__ = [
+    "AUTH_PATH",
+    "CONFIG_PATH",
+    "CACHE_DIR",
+    "DOWNLOAD_URL",
+    "DEFAULT_CODEC",
+    "MIN_FILE_SIZE",
+    "DEFAULT_CHUNK_SIZE",
+    "TABLE_COLUMN_DEFS",
+    "AUTHOR_NAME_MAX_LENGTH",
+    "AUTHOR_NAME_DISPLAY_LENGTH",
+    "PROGRESS_COLUMN_INDEX",
+    "SEEK_SECONDS",
+    "TABLE_CSS",
+]
diff --git a/auditui/constants/downloads.py b/auditui/constants/downloads.py
new file mode 100644
index 0000000..4549e15
--- /dev/null
+++ b/auditui/constants/downloads.py
@@ -0,0 +1,6 @@
+"""Download-related constants for Audible file retrieval."""
+
+DOWNLOAD_URL = "https://cde-ta-g7g.amazon.com/FionaCDEServiceEngine/FSDownloadContent"
+DEFAULT_CODEC = "LC_128_44100_stereo"
+MIN_FILE_SIZE = 1024 * 1024
+DEFAULT_CHUNK_SIZE = 8192
diff --git a/auditui/constants/library.py b/auditui/constants/library.py
new file mode 100644
index 0000000..cc7e3b9
--- /dev/null
+++ b/auditui/constants/library.py
@@ -0,0 +1,5 @@
+"""Library and table formatting constants."""
+
+AUTHOR_NAME_MAX_LENGTH = 40
+AUTHOR_NAME_DISPLAY_LENGTH = 37
+PROGRESS_COLUMN_INDEX = 3
diff --git a/auditui/constants/paths.py b/auditui/constants/paths.py
new file mode 100644
index 0000000..252fc77
--- /dev/null
+++ b/auditui/constants/paths.py
@@ -0,0 +1,8 @@
+"""Filesystem paths used by configuration and caching."""
+
+from pathlib import Path
+
+
+AUTH_PATH = Path.home() / ".config" / "auditui" / "auth.json"
+CONFIG_PATH = Path.home() / ".config" / "auditui" / "config.json"
+CACHE_DIR = Path.home() / ".cache" / "auditui" / "books"
diff --git a/auditui/constants/playback.py b/auditui/constants/playback.py
new file mode 100644
index 0000000..36a4df7
--- /dev/null
+++ b/auditui/constants/playback.py
@@ -0,0 +1,3 @@
+"""Playback behavior constants."""
+
+SEEK_SECONDS = 30.0
diff --git a/auditui/constants/table.py b/auditui/constants/table.py
new file mode 100644
index 0000000..c546a17
--- /dev/null
+++ b/auditui/constants/table.py
@@ -0,0 +1,9 @@
+"""Main library table column definitions."""
+
+TABLE_COLUMN_DEFS = (
+    ("Title", 4),
+    ("Author", 3),
+    ("Length", 1),
+    ("Progress", 1),
+    ("Downloaded", 1),
+)
diff --git a/auditui/constants/ui.py b/auditui/constants/ui.py
new file mode 100644
index 0000000..05668b7
--- /dev/null
+++ b/auditui/constants/ui.py
@@ -0,0 +1,255 @@
+"""Textual CSS constants for the application UI."""
+
+TABLE_CSS = """
+Screen {
+    background: #141622;
+}
+
+#top_bar {
+    background: #10131f;
+    color: #d5d9f0;
+    text-style: bold;
+    height: 1;
+    margin: 0;
+    padding: 0;
+}
+
+#top_left,
+#top_center,
+#top_right {
+    width: 1fr;
+    padding: 0 1;
+    background: #10131f;
+    margin: 0;
+}
+
+#top_left {
+    text-align: left;
+}
+
+#top_center {
+    text-align: center;
+}
+
+#top_right {
+    text-align: right;
+}
+
+DataTable {
+    width: 100%;
+    height: 1fr;
+    background: #141622;
+    color: #c7cfe8;
+    border: solid #262a3f;
+    scrollbar-size-horizontal: 0;
+}
+
+DataTable:focus {
+    border: solid #7aa2f7;
+}
+
+DataTable > .datatable--header {
+    background: #1b2033;
+    color: #b9c3e3;
+    text-style: bold;
+}
+
+DataTable > .datatable--cursor {
+    background: #232842;
+    color: #e6ebff;
+}
+
+DataTable > .datatable--odd-row {
+    background: #121422;
+}
+
+DataTable > .datatable--even-row {
+    background: #15182a;
+}
+
+Static {
+    height: 1;
+    text-align: center;
+    background: #10131f;
+    color: #c7cfe8;
+}
+
+Static#status {
+    color: #b6bfdc;
+}
+
+Static#progress_info {
+    color: #7aa2f7;
+    text-style: bold;
+    margin: 0;
+    padding: 0;
+    text-align: center;
+    width: 100%;
+}
+
+#progress_bar_container {
+    align: center middle;
+    width: 100%;
+    height: 1;
+}
+
+ProgressBar#progress_bar {
+    height: 1;
+    background: #10131f;
+    border: none;
+    margin: 0;
+    padding: 0;
+    width: 50%;
+}
+
+ProgressBar#progress_bar Bar {
+    width: 100%;
+}
+
+ProgressBar#progress_bar > .progress-bar--track {
+    background: #262a3f;
+}
+
+ProgressBar#progress_bar > .progress-bar--bar {
+    background: #8bd5ca;
+}
+
+HelpScreen,
+StatsScreen,
+FilterScreen {
+    align: center middle;
+    background: rgba(0, 0, 0, 0.7);
+}
+
+HelpScreen Static,
+StatsScreen Static,
+FilterScreen Static {
+    background: transparent;
+}
+
+StatsScreen #help_container {
+    width: auto;
+    min-width: 55;
+    max-width: 70;
+}
+
+StatsScreen #help_content {
+    align: center middle;
+    width: 100%;
+}
+
+StatsScreen .help_list {
+    width: 100%;
+}
+
+StatsScreen .help_list > ListItem {
+    background: transparent;
+    height: 1;
+}
+
+StatsScreen .help_list > ListItem:hover {
+    background: #232842;
+}
+
+StatsScreen .help_list > ListItem > Label {
+    width: 100%;
+    text-align: left;
+    padding-left: 2;
+}
+
+#help_container {
+    width: 72%;
+    max-width: 90;
+    min-width: 44;
+    height: auto;
+    max-height: 80%;
+    min-height: 14;
+    background: #181a2a;
+    border: heavy #7aa2f7;
+    padding: 1 1;
+}
+
+#help_title {
+    width: 100%;
+    height: 2;
+    text-align: center;
+    text-style: bold;
+    color: #7aa2f7;
+    content-align: center middle;
+    margin-bottom: 0;
+    border-bottom: solid #4b5165;
+}
+
+#help_content {
+    width: 100%;
+    height: auto;
+    padding: 0;
+    margin: 0 0 1 0;
+    align: center middle;
+}
+
+.help_list {
+    width: 100%;
+    height: auto;
+    background: transparent;
+    padding: 0;
+    scrollbar-size: 0 0;
+}
+
+.help_list > ListItem {
+    background: #1b1f33;
+    padding: 0 1;
+    height: 1;
+}
+
+.help_list > ListItem:hover {
+    background: #2a2f45;
+}
+
+.help_list > ListItem > Label {
+    width: 100%;
+    padding: 0;
+}
+
+#help_footer {
+    width: 100%;
+    height: 2;
+    text-align: center;
+    content-align: center middle;
+    color: #b6bfdc;
+    margin-top: 0;
+    border-top: solid #4b5165;
+}
+
+#filter_container {
+    width: 60;
+    height: auto;
+    background: #181a2a;
+    border: heavy #7aa2f7;
+    padding: 1 2;
+}
+
+#filter_title {
+    width: 100%;
+    height: 2;
+    text-align: center;
+    text-style: bold;
+    color: #7aa2f7;
+    content-align: center middle;
+    margin-bottom: 1;
+}
+
+#filter_input {
+    width: 100%;
+    margin: 1 0;
+}
+
+#filter_footer {
+    width: 100%;
+    height: 2;
+    text-align: center;
+    content-align: center middle;
+    color: #b6bfdc;
+    margin-top: 1;
+}
+"""