diff --git a/src/components/ui/Badge.tsx b/src/components/ui/Badge.tsx
new file mode 100644
index 0000000..08b24fd
--- /dev/null
+++ b/src/components/ui/Badge.tsx
@@ -0,0 +1,121 @@
+import React from 'react';
+import { FiX } from 'react-icons/fi';
+
+export interface BadgeProps {
+  children: React.ReactNode;
+  variant?:
+    | 'default'
+    | 'primary'
+    | 'secondary'
+    | 'success'
+    | 'warning'
+    | 'danger'
+    | 'info'
+    | 'outline';
+  size?: 'sm' | 'md' | 'lg';
+  dot?: boolean;
+  dotPulse?: boolean;
+  icon?: React.ReactNode;
+  removable?: boolean;
+  onRemove?: () => void;
+  className?: string;
+}
+
+const variantStyles: Record<NonNullable<BadgeProps['variant']>, { badge: string; dot: string }> = {
+  default: {
+    badge: 'bg-slate-100 text-slate-800 border-slate-200 dark:bg-slate-800/80 dark:text-slate-200 dark:border-slate-700',
+    dot: 'bg-slate-500',
+  },
+  primary: {
+    badge: 'bg-cyan-50 text-cyan-700 border-cyan-200 dark:bg-cyan-950/60 dark:text-cyan-300 dark:border-cyan-500/30',
+    dot: 'bg-cyan-500',
+  },
+  secondary: {
+    badge: 'bg-purple-50 text-purple-700 border-purple-200 dark:bg-purple-950/60 dark:text-purple-300 dark:border-purple-500/30',
+    dot: 'bg-purple-500',
+  },
+  success: {
+    badge: 'bg-emerald-50 text-emerald-700 border-emerald-200 dark:bg-emerald-950/60 dark:text-emerald-300 dark:border-emerald-500/30',
+    dot: 'bg-emerald-500',
+  },
+  warning: {
+    badge: 'bg-amber-50 text-amber-700 border-amber-200 dark:bg-amber-950/60 dark:text-amber-300 dark:border-amber-500/30',
+    dot: 'bg-amber-500',
+  },
+  danger: {
+    badge: 'bg-rose-50 text-rose-700 border-rose-200 dark:bg-rose-950/60 dark:text-rose-300 dark:border-rose-500/30',
+    dot: 'bg-rose-500',
+  },
+  info: {
+    badge: 'bg-sky-50 text-sky-700 border-sky-200 dark:bg-sky-950/60 dark:text-sky-300 dark:border-sky-500/30',
+    dot: 'bg-sky-500',
+  },
+  outline: {
+    badge: 'bg-transparent text-slate-700 border-slate-300 dark:text-slate-300 dark:border-slate-700',
+    dot: 'bg-slate-400',
+  },
+};
+
+const sizeStyles = {
+  sm: 'text-[10px] px-2 py-0.5 gap-1 rounded-md font-semibold',
+  md: 'text-xs px-2.5 py-1 gap-1.5 rounded-lg font-medium',
+  lg: 'text-sm px-3 py-1.5 gap-2 rounded-xl font-medium',
+};
+
+export const Badge: React.FC<BadgeProps> = ({
+  children,
+  variant = 'default',
+  size = 'md',
+  dot = false,
+  dotPulse = false,
+  icon,
+  removable = false,
+  onRemove,
+  className = '',
+}) => {
+  const currentVariant = variantStyles[variant];
+
+  return (
+    <span
+      className={`
+        inline-flex items-center select-none border transition-colors
+        ${currentVariant.badge}
+        ${sizeStyles[size]}
+        ${className}
+      `}
+    >
+      {/* Optional Dot indicator */}
+      {dot && (
+        <span className="relative flex h-1.5 w-1.5 shrink-0">
+          {dotPulse && (
+            <span
+              className={`animate-ping absolute inline-flex h-full w-full rounded-full opacity-75 ${currentVariant.dot}`}
+            />
+          )}
+          <span className={`relative inline-flex rounded-full h-1.5 w-1.5 ${currentVariant.dot}`} />
+        </span>
+      )}
+
+      {/* Optional Icon */}
+      {icon && <span className="shrink-0">{icon}</span>}
+
+      {/* Content */}
+      <span>{children}</span>
+
+      {/* Optional Remove Button */}
+      {removable && (
+        <button
+          type="button"
+          onClick={(e) => {
+            e.stopPropagation();
+            onRemove?.();
+          }}
+          className="ml-0.5 p-0.5 rounded-full hover:bg-black/10 dark:hover:bg-white/10 transition-colors"
+          aria-label="Remover etiqueta"
+        >
+          <FiX className="text-xs" />
+        </button>
+      )}
+    </span>
+  );
+};
diff --git a/src/components/ui/Button.tsx b/src/components/ui/Button.tsx
new file mode 100644
index 0000000..5991c2b
--- /dev/null
+++ b/src/components/ui/Button.tsx
@@ -0,0 +1,96 @@
+import React from 'react';
+import { Spinner } from './Spinner';
+
+export interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'outline' | 'ghost' | 'danger' | 'success' | 'gradient';
+  size?: 'xs' | 'sm' | 'md' | 'lg' | 'icon';
+  isLoading?: boolean;
+  loadingText?: string;
+  leftIcon?: React.ReactNode;
+  rightIcon?: React.ReactNode;
+  fullWidth?: boolean;
+}
+
+const variantStyles: Record<NonNullable<ButtonProps['variant']>, string> = {
+  primary:
+    'bg-cyan-500 hover:bg-cyan-400 text-slate-950 font-semibold shadow-md shadow-cyan-500/20 hover:shadow-cyan-500/30 focus-visible:ring-cyan-500 dark:bg-cyan-500 dark:hover:bg-cyan-400 dark:text-slate-950 dark:shadow-cyan-500/30',
+  secondary:
+    'bg-slate-100 hover:bg-slate-200 text-slate-800 border border-slate-200 shadow-sm focus-visible:ring-slate-400 dark:bg-slate-800 dark:hover:bg-slate-700 dark:text-slate-100 dark:border-slate-700 dark:shadow-none dark:focus-visible:ring-slate-500',
+  outline:
+    'bg-transparent border border-slate-300 text-slate-700 hover:bg-slate-100 hover:border-slate-400 focus-visible:ring-slate-400 dark:border-slate-700 dark:text-slate-200 dark:hover:bg-slate-800/80 dark:hover:border-slate-600 dark:focus-visible:ring-slate-500',
+  ghost:
+    'bg-transparent text-slate-600 hover:bg-slate-100 hover:text-slate-900 focus-visible:ring-slate-400 dark:text-slate-300 dark:hover:bg-slate-800/70 dark:hover:text-white dark:focus-visible:ring-slate-600',
+  danger:
+    'bg-rose-600 hover:bg-rose-500 text-white font-medium shadow-md shadow-rose-600/25 focus-visible:ring-rose-500 dark:bg-rose-600 dark:hover:bg-rose-500 dark:text-white',
+  success:
+    'bg-emerald-600 hover:bg-emerald-500 text-white font-medium shadow-md shadow-emerald-600/25 focus-visible:ring-emerald-500 dark:bg-emerald-500 dark:hover:bg-emerald-400 dark:text-slate-950',
+  gradient:
+    'bg-gradient-to-r from-cyan-500 via-sky-500 to-blue-600 hover:from-cyan-400 hover:via-sky-400 hover:to-blue-500 text-white font-semibold shadow-lg shadow-cyan-500/25 hover:shadow-cyan-500/40 focus-visible:ring-cyan-500 dark:from-cyan-500 dark:to-blue-600',
+};
+
+const sizeStyles: Record<NonNullable<ButtonProps['size']>, string> = {
+  xs: 'text-[11px] px-2.5 py-1 rounded-lg gap-1.5',
+  sm: 'text-xs px-3 py-1.5 rounded-xl gap-2',
+  md: 'text-sm px-4 py-2.5 rounded-xl gap-2',
+  lg: 'text-base px-6 py-3.5 rounded-2xl gap-2.5',
+  icon: 'p-2.5 rounded-xl justify-center items-center',
+};
+
+export const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
+  (
+    {
+      variant = 'primary',
+      size = 'md',
+      isLoading = false,
+      loadingText,
+      leftIcon,
+      rightIcon,
+      fullWidth = false,
+      disabled,
+      className = '',
+      children,
+      ...props
+    },
+    ref
+  ) => {
+    const isInteractiveDisabled = disabled || isLoading;
+
+    return (
+      <button
+        ref={ref}
+        disabled={isInteractiveDisabled}
+        className={`
+          relative inline-flex items-center justify-center font-medium select-none
+          transition-all duration-200 ease-out
+          focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-offset-2
+          focus-visible:ring-offset-white dark:focus-visible:ring-offset-slate-950
+          active:scale-[0.98]
+          disabled:opacity-50 disabled:cursor-not-allowed disabled:pointer-events-none disabled:active:scale-100
+          ${fullWidth ? 'w-full' : ''}
+          ${variantStyles[variant]}
+          ${sizeStyles[size]}
+          ${className}
+        `}
+        {...props}
+      >
+        {isLoading ? (
+          <>
+            <Spinner
+              size={size === 'xs' || size === 'sm' ? 'xs' : 'sm'}
+              color={variant === 'primary' || variant === 'success' ? 'slate' : 'current'}
+            />
+            {loadingText ? <span>{loadingText}</span> : children}
+          </>
+        ) : (
+          <>
+            {leftIcon && <span className="shrink-0">{leftIcon}</span>}
+            {children && <span>{children}</span>}
+            {rightIcon && <span className="shrink-0">{rightIcon}</span>}
+          </>
+        )}
+      </button>
+    );
+  }
+);
+
+Button.displayName = 'Button';
diff --git a/src/components/ui/Card.tsx b/src/components/ui/Card.tsx
new file mode 100644
index 0000000..e034e08
--- /dev/null
+++ b/src/components/ui/Card.tsx
@@ -0,0 +1,146 @@
+import React from 'react';
+
+export interface CardProps extends React.HTMLAttributes<HTMLDivElement> {
+  variant?: 'default' | 'elevated' | 'glass' | 'outline' | 'interactive';
+  padding?: 'none' | 'sm' | 'md' | 'lg';
+}
+
+const variantStyles: Record<NonNullable<CardProps['variant']>, string> = {
+  default:
+    'bg-white dark:bg-slate-900/90 border border-slate-200 dark:border-slate-800/80 shadow-sm',
+  elevated:
+    'bg-white dark:bg-slate-900 border border-slate-100 dark:border-slate-800 shadow-xl shadow-slate-200/50 dark:shadow-black/40',
+  glass:
+    'bg-white/80 dark:bg-slate-900/60 backdrop-blur-xl border border-slate-200/70 dark:border-slate-800/70 shadow-lg',
+  outline:
+    'bg-transparent border border-slate-300 dark:border-slate-800 shadow-none',
+  interactive:
+    'bg-white dark:bg-slate-900/90 border border-slate-200 dark:border-slate-800 shadow-sm hover:shadow-xl hover:shadow-cyan-500/10 hover:border-cyan-500/50 dark:hover:border-cyan-500/40 cursor-pointer transform hover:-translate-y-1 transition-all duration-300 ease-out',
+};
+
+const paddingStyles: Record<NonNullable<CardProps['padding']>, string> = {
+  none: 'p-0',
+  sm: 'p-4',
+  md: 'p-6',
+  lg: 'p-8',
+};
+
+export const Card = React.forwardRef<HTMLDivElement, CardProps>(
+  (
+    {
+      variant = 'default',
+      padding = 'none',
+      className = '',
+      children,
+      ...props
+    },
+    ref
+  ) => {
+    return (
+      <div
+        ref={ref}
+        className={`
+          rounded-2xl overflow-hidden transition-colors
+          ${variantStyles[variant]}
+          ${paddingStyles[padding]}
+          ${className}
+        `}
+        {...props}
+      >
+        {children}
+      </div>
+    );
+  }
+);
+
+Card.displayName = 'Card';
+
+export interface CardHeaderProps extends React.HTMLAttributes<HTMLDivElement> {
+  bordered?: boolean;
+}
+
+export const CardHeader: React.FC<CardHeaderProps> = ({
+  bordered = false,
+  className = '',
+  children,
+  ...props
+}) => {
+  return (
+    <div
+      className={`
+        p-5 sm:p-6 flex flex-col space-y-1.5
+        ${bordered ? 'border-b border-slate-100 dark:border-slate-800/80' : ''}
+        ${className}
+      `}
+      {...props}
+    >
+      {children}
+    </div>
+  );
+};
+
+export const CardTitle: React.FC<React.HTMLAttributes<HTMLHeadingElement>> = ({
+  className = '',
+  children,
+  ...props
+}) => {
+  return (
+    <h3
+      className={`text-lg sm:text-xl font-bold tracking-tight text-slate-900 dark:text-white transition-colors ${className}`}
+      {...props}
+    >
+      {children}
+    </h3>
+  );
+};
+
+export const CardDescription: React.FC<React.HTMLAttributes<HTMLParagraphElement>> = ({
+  className = '',
+  children,
+  ...props
+}) => {
+  return (
+    <p
+      className={`text-xs sm:text-sm text-slate-500 dark:text-slate-400 leading-relaxed ${className}`}
+      {...props}
+    >
+      {children}
+    </p>
+  );
+};
+
+export const CardContent: React.FC<React.HTMLAttributes<HTMLDivElement>> = ({
+  className = '',
+  children,
+  ...props
+}) => {
+  return (
+    <div className={`p-5 sm:p-6 ${className}`} {...props}>
+      {children}
+    </div>
+  );
+};
+
+export interface CardFooterProps extends React.HTMLAttributes<HTMLDivElement> {
+  bordered?: boolean;
+}
+
+export const CardFooter: React.FC<CardFooterProps> = ({
+  bordered = false,
+  className = '',
+  children,
+  ...props
+}) => {
+  return (
+    <div
+      className={`
+        p-5 sm:p-6 flex items-center justify-between
+        ${bordered ? 'border-t border-slate-100 dark:border-slate-800/80' : ''}
+        ${className}
+      `}
+      {...props}
+    >
+      {children}
+    </div>
+  );
+};
diff --git a/src/components/ui/Checkbox.tsx b/src/components/ui/Checkbox.tsx
new file mode 100644
index 0000000..68564c9
--- /dev/null
+++ b/src/components/ui/Checkbox.tsx
@@ -0,0 +1,111 @@
+import React, { useEffect, useRef } from 'react';
+import { FiCheck, FiMinus } from 'react-icons/fi';
+
+export interface CheckboxProps extends Omit<React.InputHTMLAttributes<HTMLInputElement>, 'type'> {
+  label?: React.ReactNode;
+  description?: string;
+  errorMessage?: string;
+  indeterminate?: boolean;
+}
+
+export const Checkbox = React.forwardRef<HTMLInputElement, CheckboxProps>(
+  (
+    {
+      label,
+      description,
+      errorMessage,
+      indeterminate = false,
+      checked,
+      disabled,
+      className = '',
+      id,
+      name,
+      ...props
+    },
+    forwardedRef
+  ) => {
+    const internalRef = useRef<HTMLInputElement>(null);
+    const resolvedRef = (forwardedRef as React.RefObject<HTMLInputElement>) || internalRef;
+    const checkboxId = id || name || (typeof label === 'string' ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+
+    useEffect(() => {
+      if (resolvedRef.current) {
+        resolvedRef.current.indeterminate = indeterminate;
+      }
+    }, [indeterminate, resolvedRef]);
+
+    const isChecked = Boolean(checked);
+
+    return (
+      <div className={`flex flex-col space-y-1 ${className}`}>
+        <label
+          htmlFor={checkboxId}
+          className={`inline-flex items-start gap-2.5 select-none cursor-pointer group ${
+            disabled ? 'opacity-50 !cursor-not-allowed' : ''
+          }`}
+        >
+          {/* Custom Styled Box */}
+          <div className="relative flex items-center justify-center mt-0.5 shrink-0">
+            <input
+              ref={resolvedRef}
+              id={checkboxId}
+              name={name}
+              type="checkbox"
+              checked={checked}
+              disabled={disabled}
+              className="peer sr-only"
+              {...props}
+            />
+
+            <div
+              className={`
+                w-4 h-4 rounded-md flex items-center justify-center transition-all duration-200
+                border
+                peer-focus-visible:ring-2 peer-focus-visible:ring-offset-2
+                peer-focus-visible:ring-cyan-500 peer-focus-visible:ring-offset-white dark:peer-focus-visible:ring-offset-slate-950
+                ${
+                  isChecked || indeterminate
+                    ? 'bg-cyan-500 border-cyan-500 text-slate-950 shadow-sm shadow-cyan-500/20'
+                    : 'bg-white dark:bg-slate-900 border-slate-300 dark:border-slate-700 text-transparent group-hover:border-slate-400 dark:group-hover:border-slate-500'
+                }
+                ${
+                  errorMessage
+                    ? '!border-rose-500 !bg-rose-50 dark:!bg-rose-950/30'
+                    : ''
+                }
+              `}
+            >
+              {indeterminate ? (
+                <FiMinus className="text-xs stroke-3" />
+              ) : isChecked ? (
+                <FiCheck className="text-xs stroke-3" />
+              ) : null}
+            </div>
+          </div>
+
+          {/* Label and Sub-description */}
+          {(label || description) && (
+            <div className="flex flex-col text-left">
+              {label && (
+                <span className="text-xs sm:text-sm font-medium text-slate-800 dark:text-slate-200 group-hover:text-slate-950 dark:group-hover:text-white transition-colors">
+                  {label}
+                </span>
+              )}
+              {description && (
+                <span className="text-xs text-slate-500 dark:text-slate-400">
+                  {description}
+                </span>
+              )}
+            </div>
+          )}
+        </label>
+
+        {errorMessage && (
+          <p className="text-xs text-rose-600 dark:text-rose-400 pl-6.5">{errorMessage}</p>
+        )}
+      </div>
+    );
+  }
+);
+
+Checkbox.displayName = 'Checkbox';
diff --git a/src/components/ui/Input.tsx b/src/components/ui/Input.tsx
new file mode 100644
index 0000000..68dc26c
--- /dev/null
+++ b/src/components/ui/Input.tsx
@@ -0,0 +1,188 @@
+import React, { useState } from 'react';
+import { FiEye, FiEyeOff, FiX, FiAlertCircle } from 'react-icons/fi';
+
+export interface InputProps extends Omit<React.InputHTMLAttributes<HTMLInputElement>, 'size'> {
+  label?: string;
+  helperText?: string;
+  errorMessage?: string;
+  leftIcon?: React.ReactNode;
+  rightIcon?: React.ReactNode;
+  isClearable?: boolean;
+  onClear?: () => void;
+  sizeVariant?: 'sm' | 'md' | 'lg';
+  fullWidth?: boolean;
+}
+
+const sizeStyles = {
+  sm: {
+    input: 'py-2 text-xs rounded-lg',
+    icon: 'text-sm',
+    leftPad: 'pl-8',
+    rightPad: 'pr-8',
+  },
+  md: {
+    input: 'py-2.5 text-sm rounded-xl',
+    icon: 'text-base',
+    leftPad: 'pl-10',
+    rightPad: 'pr-10',
+  },
+  lg: {
+    input: 'py-3.5 text-base rounded-2xl',
+    icon: 'text-lg',
+    leftPad: 'pl-12',
+    rightPad: 'pr-12',
+  },
+};
+
+export const Input = React.forwardRef<HTMLInputElement, InputProps>(
+  (
+    {
+      label,
+      helperText,
+      errorMessage,
+      leftIcon,
+      rightIcon,
+      isClearable = false,
+      onClear,
+      sizeVariant = 'md',
+      fullWidth = true,
+      type = 'text',
+      id,
+      name,
+      disabled,
+      required,
+      className = '',
+      value,
+      ...props
+    },
+    ref
+  ) => {
+    const [showPassword, setShowPassword] = useState(false);
+    const inputId = id || name || (label ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+
+    const isPasswordType = type === 'password';
+    const computedType = isPasswordType ? (showPassword ? 'text' : 'password') : type;
+    const hasError = Boolean(errorMessage);
+    const hasValue = value !== undefined && value !== '' && value !== null;
+
+    const currentSize = sizeStyles[sizeVariant];
+
+    return (
+      <div className={`${fullWidth ? 'w-full' : 'inline-block'} space-y-1.5`}>
+        {/* Label */}
+        {label && (
+          <div className="flex items-center justify-between">
+            <label
+              htmlFor={inputId}
+              className={`block text-xs font-semibold select-none transition-colors ${
+                hasError
+                  ? 'text-rose-600 dark:text-rose-400'
+                  : 'text-slate-700 dark:text-slate-300'
+              }`}
+            >
+              {label}
+              {required && <span className="ml-1 text-rose-500 font-bold">*</span>}
+            </label>
+          </div>
+        )}
+
+        {/* Input Wrapper */}
+        <div className="relative flex items-center">
+          {/* Left Icon */}
+          {leftIcon && (
+            <div
+              className={`absolute left-3.5 pointer-events-none flex items-center justify-center transition-colors ${
+                hasError
+                  ? 'text-rose-500'
+                  : 'text-slate-400 dark:text-slate-500'
+              } ${currentSize.icon}`}
+            >
+              {leftIcon}
+            </div>
+          )}
+
+          {/* Core Input Element */}
+          <input
+            ref={ref}
+            id={inputId}
+            name={name}
+            type={computedType}
+            value={value}
+            disabled={disabled}
+            required={required}
+            className={`
+              w-full px-3.5 font-normal transition-all duration-200 outline-none
+              bg-white text-slate-900 placeholder:text-slate-400
+              border border-slate-300
+              hover:border-slate-400
+              focus:border-cyan-500 focus:ring-4 focus:ring-cyan-500/15
+              dark:bg-slate-900/90 dark:text-slate-100 dark:placeholder:text-slate-500
+              dark:border-slate-800 dark:hover:border-slate-700
+              dark:focus:border-cyan-500 dark:focus:ring-cyan-500/25
+              disabled:opacity-60 disabled:bg-slate-100 disabled:dark:bg-slate-950 disabled:cursor-not-allowed
+              ${leftIcon ? currentSize.leftPad : ''}
+              ${isPasswordType || isClearable || rightIcon ? currentSize.rightPad : ''}
+              ${
+                hasError
+                  ? '!border-rose-500 !ring-rose-500/20 text-rose-900 dark:text-rose-200 focus:!border-rose-500 focus:!ring-rose-500/20'
+                  : ''
+              }
+              ${currentSize.input}
+              ${className}
+            `}
+            {...props}
+          />
+
+          {/* Right Action Icons (Clear, Password Toggle, Custom RightIcon) */}
+          <div className="absolute right-3 flex items-center gap-1.5 text-slate-400 dark:text-slate-500">
+            {isClearable && hasValue && !disabled && (
+              <button
+                type="button"
+                tabIndex={-1}
+                onClick={onClear}
+                aria-label="Limpiar campo"
+                className="p-1 rounded-md hover:bg-slate-100 hover:text-slate-700 dark:hover:bg-slate-800 dark:hover:text-slate-200 transition-colors"
+              >
+                <FiX className="text-sm" />
+              </button>
+            )}
+
+            {isPasswordType && !disabled && (
+              <button
+                type="button"
+                tabIndex={-1}
+                onClick={() => setShowPassword((prev) => !prev)}
+                aria-label={showPassword ? 'Ocultar contraseña' : 'Ver contraseña'}
+                className="p-1 rounded-md hover:bg-slate-100 hover:text-slate-700 dark:hover:bg-slate-800 dark:hover:text-slate-200 transition-colors"
+              >
+                {showPassword ? (
+                  <FiEyeOff className={currentSize.icon} />
+                ) : (
+                  <FiEye className={currentSize.icon} />
+                )}
+              </button>
+            )}
+
+            {!isPasswordType && rightIcon && (
+              <div className={`pointer-events-none flex items-center justify-center ${currentSize.icon}`}>
+                {rightIcon}
+              </div>
+            )}
+          </div>
+        </div>
+
+        {/* Error or Helper Message */}
+        {hasError ? (
+          <p className="flex items-center gap-1.5 text-xs text-rose-600 dark:text-rose-400 animate-fadeIn">
+            <FiAlertCircle className="shrink-0 text-xs" />
+            <span>{errorMessage}</span>
+          </p>
+        ) : helperText ? (
+          <p className="text-xs text-slate-500 dark:text-slate-400">{helperText}</p>
+        ) : null}
+      </div>
+    );
+  }
+);
+
+Input.displayName = 'Input';
diff --git a/src/components/ui/Modal.tsx b/src/components/ui/Modal.tsx
new file mode 100644
index 0000000..5d1d22c
--- /dev/null
+++ b/src/components/ui/Modal.tsx
@@ -0,0 +1,128 @@
+import React, { useEffect } from 'react';
+import { FiX } from 'react-icons/fi';
+
+export interface ModalProps {
+  isOpen: boolean;
+  onClose: () => void;
+  title?: React.ReactNode;
+  description?: React.ReactNode;
+  size?: 'sm' | 'md' | 'lg' | 'xl' | '2xl' | 'full';
+  children: React.ReactNode;
+  footer?: React.ReactNode;
+  closeOnOverlayClick?: boolean;
+  showCloseButton?: boolean;
+  className?: string;
+}
+
+const sizeStyles = {
+  sm: 'max-w-md',
+  md: 'max-w-lg',
+  lg: 'max-w-2xl',
+  xl: 'max-w-4xl',
+  '2xl': 'max-w-6xl',
+  full: 'max-w-[95vw] h-[90vh]',
+};
+
+export const Modal: React.FC<ModalProps> = ({
+  isOpen,
+  onClose,
+  title,
+  description,
+  size = 'md',
+  children,
+  footer,
+  closeOnOverlayClick = true,
+  showCloseButton = true,
+  className = '',
+}) => {
+  // ESC key handler and body scroll lock
+  useEffect(() => {
+    if (!isOpen) return;
+
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') {
+        onClose();
+      }
+    };
+
+    const originalOverflow = document.body.style.overflow;
+    document.body.style.overflow = 'hidden';
+    window.addEventListener('keydown', handleKeyDown);
+
+    return () => {
+      document.body.style.overflow = originalOverflow;
+      window.removeEventListener('keydown', handleKeyDown);
+    };
+  }, [isOpen, onClose]);
+
+  if (!isOpen) return null;
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      className="fixed inset-0 z-50 flex items-center justify-center p-4 sm:p-6 overflow-y-auto"
+    >
+      {/* Backdrop */}
+      <div
+        onClick={() => {
+          if (closeOnOverlayClick) onClose();
+        }}
+        className="fixed inset-0 bg-slate-950/70 backdrop-blur-md transition-opacity animate-fadeIn"
+      />
+
+      {/* Modal Dialog Card */}
+      <div
+        className={`
+          relative w-full rounded-3xl overflow-hidden shadow-2xl z-10
+          bg-white text-slate-900 border border-slate-200
+          dark:bg-slate-900/95 dark:text-slate-100 dark:border-slate-800
+          transition-all transform animate-scaleUp
+          ${sizeStyles[size]}
+          ${className}
+        `}
+      >
+        {/* Header */}
+        {(title || description || showCloseButton) && (
+          <div className="flex items-start justify-between p-6 pb-4 border-b border-slate-100 dark:border-slate-800/80">
+            <div className="space-y-1 pr-6">
+              {title && (
+                <h2 className="text-xl font-bold text-slate-900 dark:text-white tracking-tight">
+                  {title}
+                </h2>
+              )}
+              {description && (
+                <p className="text-xs sm:text-sm text-slate-500 dark:text-slate-400">
+                  {description}
+                </p>
+              )}
+            </div>
+
+            {showCloseButton && (
+              <button
+                type="button"
+                onClick={onClose}
+                aria-label="Cerrar modal"
+                className="p-2 rounded-xl text-slate-400 hover:text-slate-700 hover:bg-slate-100 dark:hover:text-slate-200 dark:hover:bg-slate-800 transition-colors"
+              >
+                <FiX className="text-lg" />
+              </button>
+            )}
+          </div>
+        )}
+
+        {/* Body Content */}
+        <div className="p-6 overflow-y-auto max-h-[calc(85vh-160px)]">
+          {children}
+        </div>
+
+        {/* Footer */}
+        {footer && (
+          <div className="p-6 pt-4 border-t border-slate-100 dark:border-slate-800/80 bg-slate-50/50 dark:bg-slate-950/40 flex items-center justify-end gap-3">
+            {footer}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+};
diff --git a/src/components/ui/Select.tsx b/src/components/ui/Select.tsx
new file mode 100644
index 0000000..433127b
--- /dev/null
+++ b/src/components/ui/Select.tsx
@@ -0,0 +1,164 @@
+import React from 'react';
+import { FiChevronDown, FiAlertCircle } from 'react-icons/fi';
+
+export interface SelectOption {
+  value: string | number;
+  label: string;
+  disabled?: boolean;
+}
+
+export interface SelectProps extends Omit<React.SelectHTMLAttributes<HTMLSelectElement>, 'size'> {
+  label?: string;
+  helperText?: string;
+  errorMessage?: string;
+  leftIcon?: React.ReactNode;
+  options?: SelectOption[];
+  sizeVariant?: 'sm' | 'md' | 'lg';
+  fullWidth?: boolean;
+}
+
+const sizeStyles = {
+  sm: {
+    select: 'py-2 text-xs rounded-lg',
+    icon: 'text-sm',
+    leftPad: 'pl-8',
+    rightPad: 'pr-8',
+  },
+  md: {
+    select: 'py-2.5 text-sm rounded-xl',
+    icon: 'text-base',
+    leftPad: 'pl-10',
+    rightPad: 'pr-10',
+  },
+  lg: {
+    select: 'py-3.5 text-base rounded-2xl',
+    icon: 'text-lg',
+    leftPad: 'pl-12',
+    rightPad: 'pr-12',
+  },
+};
+
+export const Select = React.forwardRef<HTMLSelectElement, SelectProps>(
+  (
+    {
+      label,
+      helperText,
+      errorMessage,
+      leftIcon,
+      options,
+      sizeVariant = 'md',
+      fullWidth = true,
+      id,
+      name,
+      disabled,
+      required,
+      className = '',
+      children,
+      ...props
+    },
+    ref
+  ) => {
+    const selectId = id || name || (label ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+    const hasError = Boolean(errorMessage);
+    const currentSize = sizeStyles[sizeVariant];
+
+    return (
+      <div className={`${fullWidth ? 'w-full' : 'inline-block'} space-y-1.5`}>
+        {/* Label */}
+        {label && (
+          <div className="flex items-center justify-between">
+            <label
+              htmlFor={selectId}
+              className={`block text-xs font-semibold select-none transition-colors ${
+                hasError
+                  ? 'text-rose-600 dark:text-rose-400'
+                  : 'text-slate-700 dark:text-slate-300'
+              }`}
+            >
+              {label}
+              {required && <span className="ml-1 text-rose-500 font-bold">*</span>}
+            </label>
+          </div>
+        )}
+
+        {/* Select Wrapper */}
+        <div className="relative flex items-center">
+          {/* Left Icon */}
+          {leftIcon && (
+            <div
+              className={`absolute left-3.5 pointer-events-none flex items-center justify-center transition-colors ${
+                hasError
+                  ? 'text-rose-500'
+                  : 'text-slate-400 dark:text-slate-500'
+              } ${currentSize.icon}`}
+            >
+              {leftIcon}
+            </div>
+          )}
+
+          {/* Core Select Element */}
+          <select
+            ref={ref}
+            id={selectId}
+            name={name}
+            disabled={disabled}
+            required={required}
+            className={`
+              w-full px-3.5 font-normal transition-all duration-200 outline-none appearance-none cursor-pointer
+              bg-white text-slate-900
+              border border-slate-300
+              hover:border-slate-400
+              focus:border-cyan-500 focus:ring-4 focus:ring-cyan-500/15
+              dark:bg-slate-900/90 dark:text-slate-100
+              dark:border-slate-800 dark:hover:border-slate-700
+              dark:focus:border-cyan-500 dark:focus:ring-cyan-500/25
+              disabled:opacity-60 disabled:bg-slate-100 disabled:dark:bg-slate-950 disabled:cursor-not-allowed
+              ${leftIcon ? currentSize.leftPad : ''}
+              ${currentSize.rightPad}
+              ${
+                hasError
+                  ? '!border-rose-500 !ring-rose-500/20 text-rose-900 dark:text-rose-200 focus:!border-rose-500 focus:!ring-rose-500/20'
+                  : ''
+              }
+              ${currentSize.select}
+              ${className}
+            `}
+            {...props}
+          >
+            {options
+              ? options.map((opt) => (
+                  <option
+                    key={opt.value}
+                    value={opt.value}
+                    disabled={opt.disabled}
+                    className="bg-white text-slate-900 dark:bg-slate-900 dark:text-slate-100"
+                  >
+                    {opt.label}
+                  </option>
+                ))
+              : children}
+          </select>
+
+          {/* Right Chevron Icon */}
+          <div
+            className={`absolute right-3.5 pointer-events-none flex items-center justify-center text-slate-400 dark:text-slate-500 ${currentSize.icon}`}
+          >
+            <FiChevronDown />
+          </div>
+        </div>
+
+        {/* Error or Helper Message */}
+        {hasError ? (
+          <p className="flex items-center gap-1.5 text-xs text-rose-600 dark:text-rose-400 animate-fadeIn">
+            <FiAlertCircle className="shrink-0 text-xs" />
+            <span>{errorMessage}</span>
+          </p>
+        ) : helperText ? (
+          <p className="text-xs text-slate-500 dark:text-slate-400">{helperText}</p>
+        ) : null}
+      </div>
+    );
+  }
+);
+
+Select.displayName = 'Select';
diff --git a/src/components/ui/Spinner.tsx b/src/components/ui/Spinner.tsx
new file mode 100644
index 0000000..80e2505
--- /dev/null
+++ b/src/components/ui/Spinner.tsx
@@ -0,0 +1,44 @@
+import React from 'react';
+
+export interface SpinnerProps {
+  size?: 'xs' | 'sm' | 'md' | 'lg' | 'xl';
+  color?: 'cyan' | 'blue' | 'white' | 'slate' | 'current';
+  className?: string;
+  label?: string;
+}
+
+const sizeClasses = {
+  xs: 'w-3.5 h-3.5 border-2',
+  sm: 'w-4 h-4 border-2',
+  md: 'w-6 h-6 border-2',
+  lg: 'w-8 h-8 border-3',
+  xl: 'w-12 h-12 border-4',
+};
+
+const colorClasses = {
+  cyan: 'border-cyan-500/20 border-t-cyan-500 dark:border-cyan-400/20 dark:border-t-cyan-400',
+  blue: 'border-blue-500/20 border-t-blue-500 dark:border-blue-400/20 dark:border-t-blue-400',
+  white: 'border-white/30 border-t-white',
+  slate: 'border-slate-300 border-t-slate-700 dark:border-slate-700 dark:border-t-slate-200',
+  current: 'border-current/20 border-t-current',
+};
+
+export const Spinner: React.FC<SpinnerProps> = ({
+  size = 'md',
+  color = 'cyan',
+  className = '',
+  label = 'Cargando...',
+}) => {
+  return (
+    <div
+      role="status"
+      aria-label={label}
+      className={`inline-flex items-center justify-center ${className}`}
+    >
+      <div
+        className={`rounded-full animate-spin ${sizeClasses[size]} ${colorClasses[color]}`}
+      />
+      <span className="sr-only">{label}</span>
+    </div>
+  );
+};
diff --git a/src/components/ui/Switch.tsx b/src/components/ui/Switch.tsx
new file mode 100644
index 0000000..83f8d05
--- /dev/null
+++ b/src/components/ui/Switch.tsx
@@ -0,0 +1,122 @@
+import React from 'react';
+
+export interface SwitchProps {
+  label?: React.ReactNode;
+  description?: string;
+  checked?: boolean;
+  onChange?: (checked: boolean) => void;
+  disabled?: boolean;
+  size?: 'sm' | 'md' | 'lg';
+  checkedIcon?: React.ReactNode;
+  uncheckedIcon?: React.ReactNode;
+  id?: string;
+  name?: string;
+  className?: string;
+}
+
+const trackSizes = {
+  sm: 'w-8 h-4.5',
+  md: 'w-11 h-6',
+  lg: 'w-14 h-7.5',
+};
+
+const thumbSizes = {
+  sm: 'w-3.5 h-3.5',
+  md: 'w-5 h-5',
+  lg: 'w-6.5 h-6.5',
+};
+
+const translateSizes = {
+  sm: 'translate-x-3.5',
+  md: 'translate-x-5',
+  lg: 'translate-x-6.5',
+};
+
+export const Switch: React.FC<SwitchProps> = ({
+  label,
+  description,
+  checked = false,
+  onChange,
+  disabled = false,
+  size = 'md',
+  checkedIcon,
+  uncheckedIcon,
+  id,
+  name,
+  className = '',
+}) => {
+  const switchId = id || name || (typeof label === 'string' ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+
+  const handleClick = () => {
+    if (!disabled && onChange) {
+      onChange(!checked);
+    }
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === ' ' || e.key === 'Enter') {
+      e.preventDefault();
+      handleClick();
+    }
+  };
+
+  return (
+    <div className={`inline-flex items-start gap-3 select-none ${className}`}>
+      {/* Switch Button */}
+      <button
+        id={switchId}
+        type="button"
+        role="switch"
+        aria-checked={checked}
+        disabled={disabled}
+        onClick={handleClick}
+        onKeyDown={handleKeyDown}
+        className={`
+          relative shrink-0 inline-flex items-center rounded-full p-0.5 cursor-pointer transition-colors duration-200 ease-in-out
+          focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-offset-2
+          focus-visible:ring-cyan-500 focus-visible:ring-offset-white dark:focus-visible:ring-offset-slate-950
+          disabled:opacity-50 disabled:cursor-not-allowed
+          ${trackSizes[size]}
+          ${
+            checked
+              ? 'bg-cyan-500 dark:bg-cyan-500'
+              : 'bg-slate-300 dark:bg-slate-700 hover:bg-slate-400 dark:hover:bg-slate-600'
+          }
+        `}
+      >
+        {/* Thumb */}
+        <span
+          className={`
+            pointer-events-none flex items-center justify-center rounded-full bg-white shadow-md transform transition-transform duration-200 ease-in-out text-slate-800
+            ${thumbSizes[size]}
+            ${checked ? translateSizes[size] : 'translate-x-0'}
+          `}
+        >
+          {checked ? checkedIcon : uncheckedIcon}
+        </span>
+      </button>
+
+      {/* Label and description */}
+      {(label || description) && (
+        <div className="flex flex-col text-left cursor-pointer" onClick={handleClick}>
+          {label && (
+            <span
+              className={`text-xs sm:text-sm font-medium transition-colors ${
+                disabled
+                  ? 'text-slate-400 dark:text-slate-600'
+                  : 'text-slate-800 dark:text-slate-200 hover:text-slate-950 dark:hover:text-white'
+              }`}
+            >
+              {label}
+            </span>
+          )}
+          {description && (
+            <span className="text-xs text-slate-500 dark:text-slate-400">
+              {description}
+            </span>
+          )}
+        </div>
+      )}
+    </div>
+  );
+};
diff --git a/src/components/ui/Textarea.tsx b/src/components/ui/Textarea.tsx
new file mode 100644
index 0000000..a76bd2d
--- /dev/null
+++ b/src/components/ui/Textarea.tsx
@@ -0,0 +1,117 @@
+import React from 'react';
+import { FiAlertCircle } from 'react-icons/fi';
+
+export interface TextareaProps extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {
+  label?: string;
+  helperText?: string;
+  errorMessage?: string;
+  showCharCount?: boolean;
+  fullWidth?: boolean;
+}
+
+export const Textarea = React.forwardRef<HTMLTextAreaElement, TextareaProps>(
+  (
+    {
+      label,
+      helperText,
+      errorMessage,
+      showCharCount = false,
+      fullWidth = true,
+      id,
+      name,
+      disabled,
+      required,
+      maxLength,
+      className = '',
+      value,
+      rows = 4,
+      ...props
+    },
+    ref
+  ) => {
+    const textareaId = id || name || (label ? label.toLowerCase().replace(/\s+/g, '-') : undefined);
+    const hasError = Boolean(errorMessage);
+    const currentLength = typeof value === 'string' ? value.length : 0;
+
+    return (
+      <div className={`${fullWidth ? 'w-full' : 'inline-block'} space-y-1.5`}>
+        {/* Header (Label & Character Count) */}
+        {(label || (showCharCount && maxLength)) && (
+          <div className="flex items-center justify-between">
+            {label && (
+              <label
+                htmlFor={textareaId}
+                className={`block text-xs font-semibold select-none transition-colors ${
+                  hasError
+                    ? 'text-rose-600 dark:text-rose-400'
+                    : 'text-slate-700 dark:text-slate-300'
+                }`}
+              >
+                {label}
+                {required && <span className="ml-1 text-rose-500 font-bold">*</span>}
+              </label>
+            )}
+
+            {showCharCount && maxLength && (
+              <span
+                className={`text-[11px] font-medium transition-colors ${
+                  currentLength >= maxLength
+                    ? 'text-rose-500 font-bold'
+                    : currentLength >= maxLength * 0.85
+                    ? 'text-amber-500'
+                    : 'text-slate-400 dark:text-slate-500'
+                }`}
+              >
+                {currentLength}/{maxLength}
+              </span>
+            )}
+          </div>
+        )}
+
+        {/* Core Textarea */}
+        <div className="relative">
+          <textarea
+            ref={ref}
+            id={textareaId}
+            name={name}
+            value={value}
+            disabled={disabled}
+            required={required}
+            maxLength={maxLength}
+            rows={rows}
+            className={`
+              w-full p-3.5 text-sm font-normal rounded-xl transition-all duration-200 outline-none resize-y
+              bg-white text-slate-900 placeholder:text-slate-400
+              border border-slate-300
+              hover:border-slate-400
+              focus:border-cyan-500 focus:ring-4 focus:ring-cyan-500/15
+              dark:bg-slate-900/90 dark:text-slate-100 dark:placeholder:text-slate-500
+              dark:border-slate-800 dark:hover:border-slate-700
+              dark:focus:border-cyan-500 dark:focus:ring-cyan-500/25
+              disabled:opacity-60 disabled:bg-slate-100 disabled:dark:bg-slate-950 disabled:cursor-not-allowed
+              ${
+                hasError
+                  ? '!border-rose-500 !ring-rose-500/20 text-rose-900 dark:text-rose-200 focus:!border-rose-500 focus:!ring-rose-500/20'
+                  : ''
+              }
+              ${className}
+            `}
+            {...props}
+          />
+        </div>
+
+        {/* Error or Helper Message */}
+        {hasError ? (
+          <p className="flex items-center gap-1.5 text-xs text-rose-600 dark:text-rose-400 animate-fadeIn">
+            <FiAlertCircle className="shrink-0 text-xs" />
+            <span>{errorMessage}</span>
+          </p>
+        ) : helperText ? (
+          <p className="text-xs text-slate-500 dark:text-slate-400">{helperText}</p>
+        ) : null}
+      </div>
+    );
+  }
+);
+
+Textarea.displayName = 'Textarea';
diff --git a/src/components/ui/ThemeToggle.tsx b/src/components/ui/ThemeToggle.tsx
new file mode 100644
index 0000000..811df2d
--- /dev/null
+++ b/src/components/ui/ThemeToggle.tsx
@@ -0,0 +1,133 @@
+import React, { useEffect, useState } from 'react';
+import { FiSun, FiMoon } from 'react-icons/fi';
+
+export interface ThemeToggleProps {
+  variant?: 'icon' | 'pill' | 'switch';
+  size?: 'sm' | 'md' | 'lg';
+  className?: string;
+}
+
+export const ThemeToggle: React.FC<ThemeToggleProps> = ({
+  variant = 'icon',
+  size = 'md',
+  className = '',
+}) => {
+  const [isDark, setIsDark] = useState<boolean>(() => {
+    if (typeof window === 'undefined') return true;
+    const stored = localStorage.getItem('theme');
+    if (stored) return stored === 'dark';
+    return (
+      document.documentElement.classList.contains('dark') ||
+      window.matchMedia('(prefers-color-scheme: dark)').matches
+    );
+  });
+
+  useEffect(() => {
+    const root = document.documentElement;
+    if (isDark) {
+      root.classList.add('dark');
+      localStorage.setItem('theme', 'dark');
+    } else {
+      root.classList.remove('dark');
+      localStorage.setItem('theme', 'light');
+    }
+  }, [isDark]);
+
+  const toggleTheme = () => {
+    setIsDark((prev) => !prev);
+  };
+
+  const iconSizes = {
+    sm: 'text-sm',
+    md: 'text-base',
+    lg: 'text-lg',
+  };
+
+  const paddingSizes = {
+    sm: 'p-1.5',
+    md: 'p-2.5',
+    lg: 'p-3',
+  };
+
+  if (variant === 'pill') {
+    return (
+      <button
+        type="button"
+        onClick={toggleTheme}
+        aria-label={isDark ? 'Cambiar a modo claro' : 'Cambiar a modo oscuro'}
+        className={`
+          inline-flex items-center gap-2 px-3 py-1.5 rounded-full text-xs font-semibold
+          bg-slate-100 dark:bg-slate-800 text-slate-700 dark:text-slate-200
+          border border-slate-200 dark:border-slate-700
+          hover:border-cyan-500/50 dark:hover:border-cyan-500/50
+          transition-all duration-200 shadow-sm ${className}
+        `}
+      >
+        {isDark ? (
+          <>
+            <FiMoon className="text-cyan-400" />
+            <span>Modo Oscuro</span>
+          </>
+        ) : (
+          <>
+            <FiSun className="text-amber-500" />
+            <span>Modo Claro</span>
+          </>
+        )}
+      </button>
+    );
+  }
+
+  if (variant === 'switch') {
+    return (
+      <button
+        type="button"
+        role="switch"
+        aria-checked={isDark}
+        onClick={toggleTheme}
+        aria-label="Alternar tema de color"
+        className={`
+          relative inline-flex items-center w-14 h-8 rounded-full p-1 transition-colors duration-300
+          ${isDark ? 'bg-slate-800 border border-slate-700' : 'bg-slate-200 border border-slate-300'}
+          ${className}
+        `}
+      >
+        <span
+          className={`
+            flex items-center justify-center w-6 h-6 rounded-full bg-white dark:bg-slate-900 shadow-md transform transition-transform duration-300
+            ${isDark ? 'translate-x-6 text-cyan-400' : 'translate-x-0 text-amber-500'}
+          `}
+        >
+          {isDark ? <FiMoon className="text-xs" /> : <FiSun className="text-xs" />}
+        </span>
+      </button>
+    );
+  }
+
+  // Default 'icon' variant
+  return (
+    <button
+      type="button"
+      onClick={toggleTheme}
+      aria-label={isDark ? 'Cambiar a modo claro' : 'Cambiar a modo oscuro'}
+      title={isDark ? 'Cambiar a modo claro' : 'Cambiar a modo oscuro'}
+      className={`
+        relative inline-flex items-center justify-center rounded-xl transition-all duration-200
+        bg-slate-100 dark:bg-slate-800/80 text-slate-600 dark:text-slate-300
+        border border-slate-200 dark:border-slate-700/80
+        hover:text-cyan-600 dark:hover:text-cyan-400
+        hover:border-cyan-500/40 dark:hover:border-cyan-500/40
+        hover:bg-slate-200/60 dark:hover:bg-slate-800
+        focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-500
+        ${paddingSizes[size]}
+        ${className}
+      `}
+    >
+      {isDark ? (
+        <FiSun className={`${iconSizes[size]} text-amber-400 transition-transform hover:rotate-45`} />
+      ) : (
+        <FiMoon className={`${iconSizes[size]} text-slate-700 transition-transform hover:-rotate-12`} />
+      )}
+    </button>
+  );
+};
diff --git a/src/components/ui/index.ts b/src/components/ui/index.ts
new file mode 100644
index 0000000..5edaf8c
--- /dev/null
+++ b/src/components/ui/index.ts
@@ -0,0 +1,48 @@
+// Button & Actions
+export { Button } from './Button';
+export type { ButtonProps } from './Button';
+
+// Form Fields & Inputs
+export { Input } from './Input';
+export type { InputProps } from './Input';
+
+export { Textarea } from './Textarea';
+export type { TextareaProps } from './Textarea';
+
+export { Select } from './Select';
+export type { SelectProps, SelectOption } from './Select';
+
+export { Checkbox } from './Checkbox';
+export type { CheckboxProps } from './Checkbox';
+
+export { Switch } from './Switch';
+export type { SwitchProps } from './Switch';
+
+// Feedback & Data Display
+export { Badge } from './Badge';
+export type { BadgeProps } from './Badge';
+
+export { Spinner } from './Spinner';
+export type { SpinnerProps } from './Spinner';
+
+// Layout & Overlays
+export {
+  Card,
+  CardHeader,
+  CardTitle,
+  CardDescription,
+  CardContent,
+  CardFooter,
+} from './Card';
+export type {
+  CardProps,
+  CardHeaderProps,
+  CardFooterProps,
+} from './Card';
+
+export { Modal } from './Modal';
+export type { ModalProps } from './Modal';
+
+// Theme Control
+export { ThemeToggle } from './ThemeToggle';
+export type { ThemeToggleProps } from './ThemeToggle';
diff --git a/src/index.css b/src/index.css
index d6f45c6..8ae51f3 100644
--- a/src/index.css
+++ b/src/index.css
@@ -1,5 +1,7 @@
 @import "tailwindcss";
 
+@custom-variant dark (&:where(.dark, .dark *));
+
 @layer base {
   html {
     scroll-behavior: smooth;
@@ -7,6 +9,34 @@
   }
 }
 
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+@keyframes scaleUp {
+  from {
+    opacity: 0;
+    transform: scale(0.95) translateY(8px);
+  }
+  to {
+    opacity: 1;
+    transform: scale(1) translateY(0);
+  }
+}
+
+.animate-fadeIn {
+  animation: fadeIn 0.2s ease-out forwards;
+}
+
+.animate-scaleUp {
+  animation: scaleUp 0.25s cubic-bezier(0.16, 1, 0.3, 1) forwards;
+}
+
 /* Custom modern scrollbar */
 ::-webkit-scrollbar {
   width: 8px;