feat: themes

5 files changed, 960 insertions, 0 deletions

diff --git a/internal/tui/theme/catppuccin.go b/internal/tui/theme/catppuccin.go
new file mode 100644
index 000000000..a843100ab
--- /dev/null
+++ b/internal/tui/theme/catppuccin.go
@@ -0,0 +1,248 @@
+package theme
+
+import (
+	catppuccin "github.com/catppuccin/go"
+	"github.com/charmbracelet/lipgloss"
+)
+
+// CatppuccinTheme implements the Theme interface with Catppuccin colors.
+// It provides both dark (Mocha) and light (Latte) variants.
+type CatppuccinTheme struct {
+	BaseTheme
+}
+
+// NewCatppuccinTheme creates a new instance of the Catppuccin theme.
+func NewCatppuccinTheme() *CatppuccinTheme {
+	// Get the Catppuccin palettes
+	mocha := catppuccin.Mocha
+	latte := catppuccin.Latte
+
+	theme := &CatppuccinTheme{}
+
+	// Base colors
+	theme.PrimaryColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Blue().Hex,
+		Light: latte.Blue().Hex,
+	}
+	theme.SecondaryColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Mauve().Hex,
+		Light: latte.Mauve().Hex,
+	}
+	theme.AccentColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Peach().Hex,
+		Light: latte.Peach().Hex,
+	}
+
+	// Status colors
+	theme.ErrorColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Red().Hex,
+		Light: latte.Red().Hex,
+	}
+	theme.WarningColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Peach().Hex,
+		Light: latte.Peach().Hex,
+	}
+	theme.SuccessColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Green().Hex,
+		Light: latte.Green().Hex,
+	}
+	theme.InfoColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Blue().Hex,
+		Light: latte.Blue().Hex,
+	}
+
+	// Text colors
+	theme.TextColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Text().Hex,
+		Light: latte.Text().Hex,
+	}
+	theme.TextMutedColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Subtext0().Hex,
+		Light: latte.Subtext0().Hex,
+	}
+	theme.TextEmphasizedColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Lavender().Hex,
+		Light: latte.Lavender().Hex,
+	}
+
+	// Background colors
+	theme.BackgroundColor = lipgloss.AdaptiveColor{
+		Dark:  "#212121", // From existing styles
+		Light: "#EEEEEE", // Light equivalent
+	}
+	theme.BackgroundSecondaryColor = lipgloss.AdaptiveColor{
+		Dark:  "#2c2c2c", // From existing styles
+		Light: "#E0E0E0", // Light equivalent
+	}
+	theme.BackgroundDarkerColor = lipgloss.AdaptiveColor{
+		Dark:  "#181818", // From existing styles
+		Light: "#F5F5F5", // Light equivalent
+	}
+
+	// Border colors
+	theme.BorderNormalColor = lipgloss.AdaptiveColor{
+		Dark:  "#4b4c5c", // From existing styles
+		Light: "#BDBDBD", // Light equivalent
+	}
+	theme.BorderFocusedColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Blue().Hex,
+		Light: latte.Blue().Hex,
+	}
+	theme.BorderDimColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Surface0().Hex,
+		Light: latte.Surface0().Hex,
+	}
+
+	// Diff view colors
+	theme.DiffAddedColor = lipgloss.AdaptiveColor{
+		Dark:  "#478247", // From existing diff.go
+		Light: "#2E7D32", // Light equivalent
+	}
+	theme.DiffRemovedColor = lipgloss.AdaptiveColor{
+		Dark:  "#7C4444", // From existing diff.go
+		Light: "#C62828", // Light equivalent
+	}
+	theme.DiffContextColor = lipgloss.AdaptiveColor{
+		Dark:  "#a0a0a0", // From existing diff.go
+		Light: "#757575", // Light equivalent
+	}
+	theme.DiffHunkHeaderColor = lipgloss.AdaptiveColor{
+		Dark:  "#a0a0a0", // From existing diff.go
+		Light: "#757575", // Light equivalent
+	}
+	theme.DiffHighlightAddedColor = lipgloss.AdaptiveColor{
+		Dark:  "#DAFADA", // From existing diff.go
+		Light: "#A5D6A7", // Light equivalent
+	}
+	theme.DiffHighlightRemovedColor = lipgloss.AdaptiveColor{
+		Dark:  "#FADADD", // From existing diff.go
+		Light: "#EF9A9A", // Light equivalent
+	}
+	theme.DiffAddedBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#303A30", // From existing diff.go
+		Light: "#E8F5E9", // Light equivalent
+	}
+	theme.DiffRemovedBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#3A3030", // From existing diff.go
+		Light: "#FFEBEE", // Light equivalent
+	}
+	theme.DiffContextBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#212121", // From existing diff.go
+		Light: "#F5F5F5", // Light equivalent
+	}
+	theme.DiffLineNumberColor = lipgloss.AdaptiveColor{
+		Dark:  "#888888", // From existing diff.go
+		Light: "#9E9E9E", // Light equivalent
+	}
+	theme.DiffAddedLineNumberBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#293229", // From existing diff.go
+		Light: "#C8E6C9", // Light equivalent
+	}
+	theme.DiffRemovedLineNumberBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#332929", // From existing diff.go
+		Light: "#FFCDD2", // Light equivalent
+	}
+
+	// Markdown colors
+	theme.MarkdownTextColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Text().Hex,
+		Light: latte.Text().Hex,
+	}
+	theme.MarkdownHeadingColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Mauve().Hex,
+		Light: latte.Mauve().Hex,
+	}
+	theme.MarkdownLinkColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Sky().Hex,
+		Light: latte.Sky().Hex,
+	}
+	theme.MarkdownLinkTextColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Pink().Hex,
+		Light: latte.Pink().Hex,
+	}
+	theme.MarkdownCodeColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Green().Hex,
+		Light: latte.Green().Hex,
+	}
+	theme.MarkdownBlockQuoteColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Yellow().Hex,
+		Light: latte.Yellow().Hex,
+	}
+	theme.MarkdownEmphColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Yellow().Hex,
+		Light: latte.Yellow().Hex,
+	}
+	theme.MarkdownStrongColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Peach().Hex,
+		Light: latte.Peach().Hex,
+	}
+	theme.MarkdownHorizontalRuleColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Overlay0().Hex,
+		Light: latte.Overlay0().Hex,
+	}
+	theme.MarkdownListItemColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Blue().Hex,
+		Light: latte.Blue().Hex,
+	}
+	theme.MarkdownListEnumerationColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Sky().Hex,
+		Light: latte.Sky().Hex,
+	}
+	theme.MarkdownImageColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Sapphire().Hex,
+		Light: latte.Sapphire().Hex,
+	}
+	theme.MarkdownImageTextColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Pink().Hex,
+		Light: latte.Pink().Hex,
+	}
+	theme.MarkdownCodeBlockColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Text().Hex,
+		Light: latte.Text().Hex,
+	}
+
+	// Syntax highlighting colors
+	theme.SyntaxCommentColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Overlay1().Hex,
+		Light: latte.Overlay1().Hex,
+	}
+	theme.SyntaxKeywordColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Pink().Hex,
+		Light: latte.Pink().Hex,
+	}
+	theme.SyntaxFunctionColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Green().Hex,
+		Light: latte.Green().Hex,
+	}
+	theme.SyntaxVariableColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Sky().Hex,
+		Light: latte.Sky().Hex,
+	}
+	theme.SyntaxStringColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Yellow().Hex,
+		Light: latte.Yellow().Hex,
+	}
+	theme.SyntaxNumberColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Teal().Hex,
+		Light: latte.Teal().Hex,
+	}
+	theme.SyntaxTypeColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Sky().Hex,
+		Light: latte.Sky().Hex,
+	}
+	theme.SyntaxOperatorColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Pink().Hex,
+		Light: latte.Pink().Hex,
+	}
+	theme.SyntaxPunctuationColor = lipgloss.AdaptiveColor{
+		Dark:  mocha.Text().Hex,
+		Light: latte.Text().Hex,
+	}
+
+	return theme
+}
+
+func init() {
+	// Register the Catppuccin theme with the theme manager
+	RegisterTheme("catppuccin", NewCatppuccinTheme())
+}
\ No newline at end of file
diff --git a/internal/tui/theme/gruvbox.go b/internal/tui/theme/gruvbox.go
new file mode 100644
index 000000000..ed544b84d
--- /dev/null
+++ b/internal/tui/theme/gruvbox.go
@@ -0,0 +1,302 @@
+package theme
+
+import (
+	"github.com/charmbracelet/lipgloss"
+)
+
+// Gruvbox color palette constants
+const (
+	// Dark theme colors
+	gruvboxDarkBg0          = "#282828"
+	gruvboxDarkBg0Soft      = "#32302f"
+	gruvboxDarkBg1          = "#3c3836"
+	gruvboxDarkBg2          = "#504945"
+	gruvboxDarkBg3          = "#665c54"
+	gruvboxDarkBg4          = "#7c6f64"
+	gruvboxDarkFg0          = "#fbf1c7"
+	gruvboxDarkFg1          = "#ebdbb2"
+	gruvboxDarkFg2          = "#d5c4a1"
+	gruvboxDarkFg3          = "#bdae93"
+	gruvboxDarkFg4          = "#a89984"
+	gruvboxDarkGray         = "#928374"
+	gruvboxDarkRed          = "#cc241d"
+	gruvboxDarkRedBright    = "#fb4934"
+	gruvboxDarkGreen        = "#98971a"
+	gruvboxDarkGreenBright  = "#b8bb26"
+	gruvboxDarkYellow       = "#d79921"
+	gruvboxDarkYellowBright = "#fabd2f"
+	gruvboxDarkBlue         = "#458588"
+	gruvboxDarkBlueBright   = "#83a598"
+	gruvboxDarkPurple       = "#b16286"
+	gruvboxDarkPurpleBright = "#d3869b"
+	gruvboxDarkAqua         = "#689d6a"
+	gruvboxDarkAquaBright   = "#8ec07c"
+	gruvboxDarkOrange       = "#d65d0e"
+	gruvboxDarkOrangeBright = "#fe8019"
+
+	// Light theme colors
+	gruvboxLightBg0          = "#fbf1c7"
+	gruvboxLightBg0Soft      = "#f2e5bc"
+	gruvboxLightBg1          = "#ebdbb2"
+	gruvboxLightBg2          = "#d5c4a1"
+	gruvboxLightBg3          = "#bdae93"
+	gruvboxLightBg4          = "#a89984"
+	gruvboxLightFg0          = "#282828"
+	gruvboxLightFg1          = "#3c3836"
+	gruvboxLightFg2          = "#504945"
+	gruvboxLightFg3          = "#665c54"
+	gruvboxLightFg4          = "#7c6f64"
+	gruvboxLightGray         = "#928374"
+	gruvboxLightRed          = "#9d0006"
+	gruvboxLightRedBright    = "#cc241d"
+	gruvboxLightGreen        = "#79740e"
+	gruvboxLightGreenBright  = "#98971a"
+	gruvboxLightYellow       = "#b57614"
+	gruvboxLightYellowBright = "#d79921"
+	gruvboxLightBlue         = "#076678"
+	gruvboxLightBlueBright   = "#458588"
+	gruvboxLightPurple       = "#8f3f71"
+	gruvboxLightPurpleBright = "#b16286"
+	gruvboxLightAqua         = "#427b58"
+	gruvboxLightAquaBright   = "#689d6a"
+	gruvboxLightOrange       = "#af3a03"
+	gruvboxLightOrangeBright = "#d65d0e"
+)
+
+// GruvboxTheme implements the Theme interface with Gruvbox colors.
+// It provides both dark and light variants.
+type GruvboxTheme struct {
+	BaseTheme
+}
+
+// NewGruvboxTheme creates a new instance of the Gruvbox theme.
+func NewGruvboxTheme() *GruvboxTheme {
+	theme := &GruvboxTheme{}
+
+	// Base colors
+	theme.PrimaryColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.SecondaryColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkPurpleBright,
+		Light: gruvboxLightPurpleBright,
+	}
+	theme.AccentColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkOrangeBright,
+		Light: gruvboxLightOrangeBright,
+	}
+
+	// Status colors
+	theme.ErrorColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkRedBright,
+		Light: gruvboxLightRedBright,
+	}
+	theme.WarningColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellowBright,
+		Light: gruvboxLightYellowBright,
+	}
+	theme.SuccessColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGreenBright,
+		Light: gruvboxLightGreenBright,
+	}
+	theme.InfoColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+
+	// Text colors
+	theme.TextColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg1,
+		Light: gruvboxLightFg1,
+	}
+	theme.TextMutedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg4,
+		Light: gruvboxLightFg4,
+	}
+	theme.TextEmphasizedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellowBright,
+		Light: gruvboxLightYellowBright,
+	}
+
+	// Background colors
+	theme.BackgroundColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg0,
+		Light: gruvboxLightBg0,
+	}
+	theme.BackgroundSecondaryColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg1,
+		Light: gruvboxLightBg1,
+	}
+	theme.BackgroundDarkerColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg0Soft,
+		Light: gruvboxLightBg0Soft,
+	}
+
+	// Border colors
+	theme.BorderNormalColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg2,
+		Light: gruvboxLightBg2,
+	}
+	theme.BorderFocusedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.BorderDimColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg1,
+		Light: gruvboxLightBg1,
+	}
+
+	// Diff view colors
+	theme.DiffAddedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGreenBright,
+		Light: gruvboxLightGreenBright,
+	}
+	theme.DiffRemovedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkRedBright,
+		Light: gruvboxLightRedBright,
+	}
+	theme.DiffContextColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg4,
+		Light: gruvboxLightFg4,
+	}
+	theme.DiffHunkHeaderColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg3,
+		Light: gruvboxLightFg3,
+	}
+	theme.DiffHighlightAddedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGreenBright,
+		Light: gruvboxLightGreenBright,
+	}
+	theme.DiffHighlightRemovedColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkRedBright,
+		Light: gruvboxLightRedBright,
+	}
+	theme.DiffAddedBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#3C4C3C",  // Darker green background
+		Light: "#E8F5E9", // Light green background
+	}
+	theme.DiffRemovedBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#4C3C3C",  // Darker red background
+		Light: "#FFEBEE", // Light red background
+	}
+	theme.DiffContextBgColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg0,
+		Light: gruvboxLightBg0,
+	}
+	theme.DiffLineNumberColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg4,
+		Light: gruvboxLightFg4,
+	}
+	theme.DiffAddedLineNumberBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#32432F",   // Slightly darker green
+		Light: "#C8E6C9", // Light green
+	}
+	theme.DiffRemovedLineNumberBgColor = lipgloss.AdaptiveColor{
+		Dark:  "#43322F",   // Slightly darker red
+		Light: "#FFCDD2", // Light red
+	}
+
+	// Markdown colors
+	theme.MarkdownTextColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg1,
+		Light: gruvboxLightFg1,
+	}
+	theme.MarkdownHeadingColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellowBright,
+		Light: gruvboxLightYellowBright,
+	}
+	theme.MarkdownLinkColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.MarkdownLinkTextColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkAquaBright,
+		Light: gruvboxLightAquaBright,
+	}
+	theme.MarkdownCodeColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGreenBright,
+		Light: gruvboxLightGreenBright,
+	}
+	theme.MarkdownBlockQuoteColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkAquaBright,
+		Light: gruvboxLightAquaBright,
+	}
+	theme.MarkdownEmphColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellowBright,
+		Light: gruvboxLightYellowBright,
+	}
+	theme.MarkdownStrongColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkOrangeBright,
+		Light: gruvboxLightOrangeBright,
+	}
+	theme.MarkdownHorizontalRuleColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBg3,
+		Light: gruvboxLightBg3,
+	}
+	theme.MarkdownListItemColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.MarkdownListEnumerationColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.MarkdownImageColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkPurpleBright,
+		Light: gruvboxLightPurpleBright,
+	}
+	theme.MarkdownImageTextColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkAquaBright,
+		Light: gruvboxLightAquaBright,
+	}
+	theme.MarkdownCodeBlockColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg1,
+		Light: gruvboxLightFg1,
+	}
+
+	// Syntax highlighting colors
+	theme.SyntaxCommentColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGray,
+		Light: gruvboxLightGray,
+	}
+	theme.SyntaxKeywordColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkRedBright,
+		Light: gruvboxLightRedBright,
+	}
+	theme.SyntaxFunctionColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkGreenBright,
+		Light: gruvboxLightGreenBright,
+	}
+	theme.SyntaxVariableColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkBlueBright,
+		Light: gruvboxLightBlueBright,
+	}
+	theme.SyntaxStringColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellowBright,
+		Light: gruvboxLightYellowBright,
+	}
+	theme.SyntaxNumberColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkPurpleBright,
+		Light: gruvboxLightPurpleBright,
+	}
+	theme.SyntaxTypeColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkYellow,
+		Light: gruvboxLightYellow,
+	}
+	theme.SyntaxOperatorColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkAquaBright,
+		Light: gruvboxLightAquaBright,
+	}
+	theme.SyntaxPunctuationColor = lipgloss.AdaptiveColor{
+		Dark:  gruvboxDarkFg1,
+		Light: gruvboxLightFg1,
+	}
+
+	return theme
+}
+
+func init() {
+	// Register the Gruvbox theme with the theme manager
+	RegisterTheme("gruvbox", NewGruvboxTheme())
+}
\ No newline at end of file
diff --git a/internal/tui/theme/manager.go b/internal/tui/theme/manager.go
new file mode 100644
index 000000000..161563c26
--- /dev/null
+++ b/internal/tui/theme/manager.go
@@ -0,0 +1,113 @@
+package theme
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+	"sync"
+
+	"github.com/alecthomas/chroma/v2/styles"
+	"github.com/opencode-ai/opencode/internal/config"
+	"github.com/opencode-ai/opencode/internal/logging"
+)
+
+// Manager handles theme registration, selection, and retrieval.
+// It maintains a registry of available themes and tracks the currently active theme.
+type Manager struct {
+	themes      map[string]Theme
+	currentName string
+	mu          sync.RWMutex
+}
+
+// Global instance of the theme manager
+var globalManager = &Manager{
+	themes:      make(map[string]Theme),
+	currentName: "",
+}
+
+// RegisterTheme adds a new theme to the registry.
+// If this is the first theme registered, it becomes the default.
+func RegisterTheme(name string, theme Theme) {
+	globalManager.mu.Lock()
+	defer globalManager.mu.Unlock()
+
+	globalManager.themes[name] = theme
+
+	// If this is the first theme, make it the default
+	if globalManager.currentName == "" {
+		globalManager.currentName = name
+	}
+}
+
+// SetTheme changes the active theme to the one with the specified name.
+// Returns an error if the theme doesn't exist.
+func SetTheme(name string) error {
+	globalManager.mu.Lock()
+	defer globalManager.mu.Unlock()
+
+	delete(styles.Registry, "charm")
+	if _, exists := globalManager.themes[name]; !exists {
+		return fmt.Errorf("theme '%s' not found", name)
+	}
+
+	globalManager.currentName = name
+
+	// Update the config file using viper
+	if err := updateConfigTheme(name); err != nil {
+		// Log the error but don't fail the theme change
+		logging.Warn("Warning: Failed to update config file with new theme", "err", err)
+	}
+
+	return nil
+}
+
+// CurrentTheme returns the currently active theme.
+// If no theme is set, it returns nil.
+func CurrentTheme() Theme {
+	globalManager.mu.RLock()
+	defer globalManager.mu.RUnlock()
+
+	if globalManager.currentName == "" {
+		return nil
+	}
+
+	return globalManager.themes[globalManager.currentName]
+}
+
+// CurrentThemeName returns the name of the currently active theme.
+func CurrentThemeName() string {
+	globalManager.mu.RLock()
+	defer globalManager.mu.RUnlock()
+
+	return globalManager.currentName
+}
+
+// AvailableThemes returns a list of all registered theme names.
+func AvailableThemes() []string {
+	globalManager.mu.RLock()
+	defer globalManager.mu.RUnlock()
+
+	names := make([]string, 0, len(globalManager.themes))
+	for name := range globalManager.themes {
+		names = append(names, name)
+	}
+	slices.SortFunc(names, func(a, b string) int {
+		return strings.Compare(a, b)
+	})
+	return names
+}
+
+// GetTheme returns a specific theme by name.
+// Returns nil if the theme doesn't exist.
+func GetTheme(name string) Theme {
+	globalManager.mu.RLock()
+	defer globalManager.mu.RUnlock()
+
+	return globalManager.themes[name]
+}
+
+// updateConfigTheme updates the theme setting in the configuration file
+func updateConfigTheme(themeName string) error {
+	// Use the config package to update the theme
+	return config.UpdateTheme(themeName)
+}
diff --git a/internal/tui/theme/theme.go b/internal/tui/theme/theme.go
new file mode 100644
index 000000000..4ee14a07f
--- /dev/null
+++ b/internal/tui/theme/theme.go
@@ -0,0 +1,208 @@
+package theme
+
+import (
+	"github.com/charmbracelet/lipgloss"
+)
+
+// Theme defines the interface for all UI themes in the application.
+// All colors must be defined as lipgloss.AdaptiveColor to support
+// both light and dark terminal backgrounds.
+type Theme interface {
+	// Base colors
+	Primary() lipgloss.AdaptiveColor
+	Secondary() lipgloss.AdaptiveColor
+	Accent() lipgloss.AdaptiveColor
+
+	// Status colors
+	Error() lipgloss.AdaptiveColor
+	Warning() lipgloss.AdaptiveColor
+	Success() lipgloss.AdaptiveColor
+	Info() lipgloss.AdaptiveColor
+
+	// Text colors
+	Text() lipgloss.AdaptiveColor
+	TextMuted() lipgloss.AdaptiveColor
+	TextEmphasized() lipgloss.AdaptiveColor
+
+	// Background colors
+	Background() lipgloss.AdaptiveColor
+	BackgroundSecondary() lipgloss.AdaptiveColor
+	BackgroundDarker() lipgloss.AdaptiveColor
+
+	// Border colors
+	BorderNormal() lipgloss.AdaptiveColor
+	BorderFocused() lipgloss.AdaptiveColor
+	BorderDim() lipgloss.AdaptiveColor
+
+	// Diff view colors
+	DiffAdded() lipgloss.AdaptiveColor
+	DiffRemoved() lipgloss.AdaptiveColor
+	DiffContext() lipgloss.AdaptiveColor
+	DiffHunkHeader() lipgloss.AdaptiveColor
+	DiffHighlightAdded() lipgloss.AdaptiveColor
+	DiffHighlightRemoved() lipgloss.AdaptiveColor
+	DiffAddedBg() lipgloss.AdaptiveColor
+	DiffRemovedBg() lipgloss.AdaptiveColor
+	DiffContextBg() lipgloss.AdaptiveColor
+	DiffLineNumber() lipgloss.AdaptiveColor
+	DiffAddedLineNumberBg() lipgloss.AdaptiveColor
+	DiffRemovedLineNumberBg() lipgloss.AdaptiveColor
+
+	// Markdown colors
+	MarkdownText() lipgloss.AdaptiveColor
+	MarkdownHeading() lipgloss.AdaptiveColor
+	MarkdownLink() lipgloss.AdaptiveColor
+	MarkdownLinkText() lipgloss.AdaptiveColor
+	MarkdownCode() lipgloss.AdaptiveColor
+	MarkdownBlockQuote() lipgloss.AdaptiveColor
+	MarkdownEmph() lipgloss.AdaptiveColor
+	MarkdownStrong() lipgloss.AdaptiveColor
+	MarkdownHorizontalRule() lipgloss.AdaptiveColor
+	MarkdownListItem() lipgloss.AdaptiveColor
+	MarkdownListEnumeration() lipgloss.AdaptiveColor
+	MarkdownImage() lipgloss.AdaptiveColor
+	MarkdownImageText() lipgloss.AdaptiveColor
+	MarkdownCodeBlock() lipgloss.AdaptiveColor
+
+	// Syntax highlighting colors
+	SyntaxComment() lipgloss.AdaptiveColor
+	SyntaxKeyword() lipgloss.AdaptiveColor
+	SyntaxFunction() lipgloss.AdaptiveColor
+	SyntaxVariable() lipgloss.AdaptiveColor
+	SyntaxString() lipgloss.AdaptiveColor
+	SyntaxNumber() lipgloss.AdaptiveColor
+	SyntaxType() lipgloss.AdaptiveColor
+	SyntaxOperator() lipgloss.AdaptiveColor
+	SyntaxPunctuation() lipgloss.AdaptiveColor
+}
+
+// BaseTheme provides a default implementation of the Theme interface
+// that can be embedded in concrete theme implementations.
+type BaseTheme struct {
+	// Base colors
+	PrimaryColor       lipgloss.AdaptiveColor
+	SecondaryColor     lipgloss.AdaptiveColor
+	AccentColor        lipgloss.AdaptiveColor
+
+	// Status colors
+	ErrorColor         lipgloss.AdaptiveColor
+	WarningColor       lipgloss.AdaptiveColor
+	SuccessColor       lipgloss.AdaptiveColor
+	InfoColor          lipgloss.AdaptiveColor
+
+	// Text colors
+	TextColor          lipgloss.AdaptiveColor
+	TextMutedColor     lipgloss.AdaptiveColor
+	TextEmphasizedColor lipgloss.AdaptiveColor
+
+	// Background colors
+	BackgroundColor    lipgloss.AdaptiveColor
+	BackgroundSecondaryColor lipgloss.AdaptiveColor
+	BackgroundDarkerColor lipgloss.AdaptiveColor
+
+	// Border colors
+	BorderNormalColor  lipgloss.AdaptiveColor
+	BorderFocusedColor lipgloss.AdaptiveColor
+	BorderDimColor     lipgloss.AdaptiveColor
+
+	// Diff view colors
+	DiffAddedColor     lipgloss.AdaptiveColor
+	DiffRemovedColor   lipgloss.AdaptiveColor
+	DiffContextColor   lipgloss.AdaptiveColor
+	DiffHunkHeaderColor lipgloss.AdaptiveColor
+	DiffHighlightAddedColor lipgloss.AdaptiveColor
+	DiffHighlightRemovedColor lipgloss.AdaptiveColor
+	DiffAddedBgColor   lipgloss.AdaptiveColor
+	DiffRemovedBgColor lipgloss.AdaptiveColor
+	DiffContextBgColor lipgloss.AdaptiveColor
+	DiffLineNumberColor lipgloss.AdaptiveColor
+	DiffAddedLineNumberBgColor lipgloss.AdaptiveColor
+	DiffRemovedLineNumberBgColor lipgloss.AdaptiveColor
+
+	// Markdown colors
+	MarkdownTextColor  lipgloss.AdaptiveColor
+	MarkdownHeadingColor lipgloss.AdaptiveColor
+	MarkdownLinkColor  lipgloss.AdaptiveColor
+	MarkdownLinkTextColor lipgloss.AdaptiveColor
+	MarkdownCodeColor  lipgloss.AdaptiveColor
+	MarkdownBlockQuoteColor lipgloss.AdaptiveColor
+	MarkdownEmphColor  lipgloss.AdaptiveColor
+	MarkdownStrongColor lipgloss.AdaptiveColor
+	MarkdownHorizontalRuleColor lipgloss.AdaptiveColor
+	MarkdownListItemColor lipgloss.AdaptiveColor
+	MarkdownListEnumerationColor lipgloss.AdaptiveColor
+	MarkdownImageColor lipgloss.AdaptiveColor
+	MarkdownImageTextColor lipgloss.AdaptiveColor
+	MarkdownCodeBlockColor lipgloss.AdaptiveColor
+
+	// Syntax highlighting colors
+	SyntaxCommentColor lipgloss.AdaptiveColor
+	SyntaxKeywordColor lipgloss.AdaptiveColor
+	SyntaxFunctionColor lipgloss.AdaptiveColor
+	SyntaxVariableColor lipgloss.AdaptiveColor
+	SyntaxStringColor  lipgloss.AdaptiveColor
+	SyntaxNumberColor  lipgloss.AdaptiveColor
+	SyntaxTypeColor    lipgloss.AdaptiveColor
+	SyntaxOperatorColor lipgloss.AdaptiveColor
+	SyntaxPunctuationColor lipgloss.AdaptiveColor
+}
+
+// Implement the Theme interface for BaseTheme
+func (t *BaseTheme) Primary() lipgloss.AdaptiveColor { return t.PrimaryColor }
+func (t *BaseTheme) Secondary() lipgloss.AdaptiveColor { return t.SecondaryColor }
+func (t *BaseTheme) Accent() lipgloss.AdaptiveColor { return t.AccentColor }
+
+func (t *BaseTheme) Error() lipgloss.AdaptiveColor { return t.ErrorColor }
+func (t *BaseTheme) Warning() lipgloss.AdaptiveColor { return t.WarningColor }
+func (t *BaseTheme) Success() lipgloss.AdaptiveColor { return t.SuccessColor }
+func (t *BaseTheme) Info() lipgloss.AdaptiveColor { return t.InfoColor }
+
+func (t *BaseTheme) Text() lipgloss.AdaptiveColor { return t.TextColor }
+func (t *BaseTheme) TextMuted() lipgloss.AdaptiveColor { return t.TextMutedColor }
+func (t *BaseTheme) TextEmphasized() lipgloss.AdaptiveColor { return t.TextEmphasizedColor }
+
+func (t *BaseTheme) Background() lipgloss.AdaptiveColor { return t.BackgroundColor }
+func (t *BaseTheme) BackgroundSecondary() lipgloss.AdaptiveColor { return t.BackgroundSecondaryColor }
+func (t *BaseTheme) BackgroundDarker() lipgloss.AdaptiveColor { return t.BackgroundDarkerColor }
+
+func (t *BaseTheme) BorderNormal() lipgloss.AdaptiveColor { return t.BorderNormalColor }
+func (t *BaseTheme) BorderFocused() lipgloss.AdaptiveColor { return t.BorderFocusedColor }
+func (t *BaseTheme) BorderDim() lipgloss.AdaptiveColor { return t.BorderDimColor }
+
+func (t *BaseTheme) DiffAdded() lipgloss.AdaptiveColor { return t.DiffAddedColor }
+func (t *BaseTheme) DiffRemoved() lipgloss.AdaptiveColor { return t.DiffRemovedColor }
+func (t *BaseTheme) DiffContext() lipgloss.AdaptiveColor { return t.DiffContextColor }
+func (t *BaseTheme) DiffHunkHeader() lipgloss.AdaptiveColor { return t.DiffHunkHeaderColor }
+func (t *BaseTheme) DiffHighlightAdded() lipgloss.AdaptiveColor { return t.DiffHighlightAddedColor }
+func (t *BaseTheme) DiffHighlightRemoved() lipgloss.AdaptiveColor { return t.DiffHighlightRemovedColor }
+func (t *BaseTheme) DiffAddedBg() lipgloss.AdaptiveColor { return t.DiffAddedBgColor }
+func (t *BaseTheme) DiffRemovedBg() lipgloss.AdaptiveColor { return t.DiffRemovedBgColor }
+func (t *BaseTheme) DiffContextBg() lipgloss.AdaptiveColor { return t.DiffContextBgColor }
+func (t *BaseTheme) DiffLineNumber() lipgloss.AdaptiveColor { return t.DiffLineNumberColor }
+func (t *BaseTheme) DiffAddedLineNumberBg() lipgloss.AdaptiveColor { return t.DiffAddedLineNumberBgColor }
+func (t *BaseTheme) DiffRemovedLineNumberBg() lipgloss.AdaptiveColor { return t.DiffRemovedLineNumberBgColor }
+
+func (t *BaseTheme) MarkdownText() lipgloss.AdaptiveColor { return t.MarkdownTextColor }
+func (t *BaseTheme) MarkdownHeading() lipgloss.AdaptiveColor { return t.MarkdownHeadingColor }
+func (t *BaseTheme) MarkdownLink() lipgloss.AdaptiveColor { return t.MarkdownLinkColor }
+func (t *BaseTheme) MarkdownLinkText() lipgloss.AdaptiveColor { return t.MarkdownLinkTextColor }
+func (t *BaseTheme) MarkdownCode() lipgloss.AdaptiveColor { return t.MarkdownCodeColor }
+func (t *BaseTheme) MarkdownBlockQuote() lipgloss.AdaptiveColor { return t.MarkdownBlockQuoteColor }
+func (t *BaseTheme) MarkdownEmph() lipgloss.AdaptiveColor { return t.MarkdownEmphColor }
+func (t *BaseTheme) MarkdownStrong() lipgloss.AdaptiveColor { return t.MarkdownStrongColor }
+func (t *BaseTheme) MarkdownHorizontalRule() lipgloss.AdaptiveColor { return t.MarkdownHorizontalRuleColor }
+func (t *BaseTheme) MarkdownListItem() lipgloss.AdaptiveColor { return t.MarkdownListItemColor }
+func (t *BaseTheme) MarkdownListEnumeration() lipgloss.AdaptiveColor { return t.MarkdownListEnumerationColor }
+func (t *BaseTheme) MarkdownImage() lipgloss.AdaptiveColor { return t.MarkdownImageColor }
+func (t *BaseTheme) MarkdownImageText() lipgloss.AdaptiveColor { return t.MarkdownImageTextColor }
+func (t *BaseTheme) MarkdownCodeBlock() lipgloss.AdaptiveColor { return t.MarkdownCodeBlockColor }
+
+func (t *BaseTheme) SyntaxComment() lipgloss.AdaptiveColor { return t.SyntaxCommentColor }
+func (t *BaseTheme) SyntaxKeyword() lipgloss.AdaptiveColor { return t.SyntaxKeywordColor }
+func (t *BaseTheme) SyntaxFunction() lipgloss.AdaptiveColor { return t.SyntaxFunctionColor }
+func (t *BaseTheme) SyntaxVariable() lipgloss.AdaptiveColor { return t.SyntaxVariableColor }
+func (t *BaseTheme) SyntaxString() lipgloss.AdaptiveColor { return t.SyntaxStringColor }
+func (t *BaseTheme) SyntaxNumber() lipgloss.AdaptiveColor { return t.SyntaxNumberColor }
+func (t *BaseTheme) SyntaxType() lipgloss.AdaptiveColor { return t.SyntaxTypeColor }
+func (t *BaseTheme) SyntaxOperator() lipgloss.AdaptiveColor { return t.SyntaxOperatorColor }
+func (t *BaseTheme) SyntaxPunctuation() lipgloss.AdaptiveColor { return t.SyntaxPunctuationColor }
\ No newline at end of file
diff --git a/internal/tui/theme/theme_test.go b/internal/tui/theme/theme_test.go
new file mode 100644
index 000000000..5ec810e33
--- /dev/null
+++ b/internal/tui/theme/theme_test.go
@@ -0,0 +1,89 @@
+package theme
+
+import (
+	"testing"
+)
+
+func TestThemeRegistration(t *testing.T) {
+	// Get list of available themes
+	availableThemes := AvailableThemes()
+	
+	// Check if "catppuccin" theme is registered
+	catppuccinFound := false
+	for _, themeName := range availableThemes {
+		if themeName == "catppuccin" {
+			catppuccinFound = true
+			break
+		}
+	}
+	
+	if !catppuccinFound {
+		t.Errorf("Catppuccin theme is not registered")
+	}
+	
+	// Check if "gruvbox" theme is registered
+	gruvboxFound := false
+	for _, themeName := range availableThemes {
+		if themeName == "gruvbox" {
+			gruvboxFound = true
+			break
+		}
+	}
+	
+	if !gruvboxFound {
+		t.Errorf("Gruvbox theme is not registered")
+	}
+	
+	// Check if "monokai" theme is registered
+	monokaiFound := false
+	for _, themeName := range availableThemes {
+		if themeName == "monokai" {
+			monokaiFound = true
+			break
+		}
+	}
+	
+	if !monokaiFound {
+		t.Errorf("Monokai theme is not registered")
+	}
+	
+	// Try to get the themes and make sure they're not nil
+	catppuccin := GetTheme("catppuccin")
+	if catppuccin == nil {
+		t.Errorf("Catppuccin theme is nil")
+	}
+	
+	gruvbox := GetTheme("gruvbox")
+	if gruvbox == nil {
+		t.Errorf("Gruvbox theme is nil")
+	}
+	
+	monokai := GetTheme("monokai")
+	if monokai == nil {
+		t.Errorf("Monokai theme is nil")
+	}
+	
+	// Test switching theme
+	originalTheme := CurrentThemeName()
+	
+	err := SetTheme("gruvbox")
+	if err != nil {
+		t.Errorf("Failed to set theme to gruvbox: %v", err)
+	}
+	
+	if CurrentThemeName() != "gruvbox" {
+		t.Errorf("Theme not properly switched to gruvbox")
+	}
+	
+	err = SetTheme("monokai")
+	if err != nil {
+		t.Errorf("Failed to set theme to monokai: %v", err)
+	}
+	
+	if CurrentThemeName() != "monokai" {
+		t.Errorf("Theme not properly switched to monokai")
+	}
+	
+	// Switch back to original theme
+	_ = SetTheme(originalTheme)
+}
\ No newline at end of file