diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..3ac5c15
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,44 @@
+package config
+
+import (
+	"fmt"
+	"github.com/spf13/viper"
+)
+
+// Config stores all configuration for the application.
+// The values are read by viper from a config file or environment variables.
+type Config struct {
+	Title          string `mapstructure:"title"`
+	DefaultFile    string `mapstructure:"default_file"`
+	ShowTOC        bool   `mapstructure:"show_toc"`
+}
+
+// LoadConfig reads configuration from file or environment variables.
+func LoadConfig() (config Config, err error) {
+	viper.AddConfigPath(".")
+	viper.SetConfigName("config")
+	viper.SetConfigType("toml")
+
+	// Set default values
+	viper.SetDefault("title", "GemReader")
+	viper.SetDefault("default_file", "")
+	viper.SetDefault("show_toc", false)
+
+	viper.AutomaticEnv()
+
+	if err = viper.ReadInConfig(); err != nil {
+		// Don't return error if config file doesn't exist, just use defaults
+		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
+			// Config file not found, proceed with defaults
+			err = nil
+		} else {
+			return config, fmt.Errorf("error reading config file: %w", err)
+		}
+	}
+
+	if err = viper.Unmarshal(&config); err != nil {
+		return config, fmt.Errorf("error parsing config file: %w", err)
+	}
+
+	return config, nil
+}