---

Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.SignUpLoginInv4">
        <activity
            android:name=".LoginIn"
            android:exported="false"
            android:theme="@style/Theme.SignUpLoginInv4" />
        <activity
            android:name=".SignUp"
            android:exported="true"
            android:label="@string/app_name"
            android:theme="@style/Theme.SignUpLoginInv4">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>
Login:
package com.example.signuplogininv4

import android.content.Intent
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.KeyboardOptions
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Visibility
import androidx.compose.material.icons.filled.VisibilityOff
import androidx.compose.material3.Button
import androidx.compose.material3.ButtonDefaults
import androidx.compose.material3.Card
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedTextField
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.input.KeyboardType
import androidx.compose.ui.text.input.PasswordVisualTransformation
import androidx.compose.ui.text.input.VisualTransformation
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

class LoginIn : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

        val startEmail = intent.getStringExtra(EXTRA_EMAIL).orEmpty()
        val startPassword = intent.getStringExtra(EXTRA_PASSWORD).orEmpty()

        setContent {
            LoginInScreen(
                initialEmail = startEmail,
                initialPassword = startPassword,
                onSignUpClick = {
                    startActivity(Intent(this, SignUp::class.java))
                }
            )
        }
    }

    companion object {
        const val EXTRA_EMAIL = "extra_email"
        const val EXTRA_PASSWORD = "extra_password"
    }
}

@Composable
fun LoginInScreen(
    initialEmail: String,
    initialPassword: String,
    onSignUpClick: () -> Unit
) {
    var email by remember { mutableStateOf(initialEmail) }
    var password by remember { mutableStateOf(initialPassword) }
    var emailError by remember { mutableStateOf<String?>(null) }
    var passwordError by remember { mutableStateOf<String?>(null) }
    var passwordVisible by remember { mutableStateOf(false) }

    val gradient = Brush.linearGradient(
        colors = listOf(Color(0xFF2473E6), Color(0xFF1CE0DA)),
        start = Offset.Zero,
        end = Offset.Infinite
    )

    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(gradient)
            .verticalScroll(rememberScrollState())
            .padding(horizontal = 16.dp, vertical = 24.dp),
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        LogoHeader()
        Spacer(modifier = Modifier.height(20.dp))

        Card(
            modifier = Modifier.fillMaxWidth(),
            shape = RoundedCornerShape(24.dp)
        ) {
            Column(
                modifier = Modifier
                    .fillMaxWidth()
                    .background(Color.White)
                    .padding(horizontal = 24.dp, vertical = 28.dp),
                horizontalAlignment = Alignment.CenterHorizontally
            ) {
                Text(
                    text = "Вход",
                    fontSize = 36.sp,
                    fontWeight = FontWeight.Bold,
                    color = Color(0xFF111827)
                )

                Spacer(modifier = Modifier.height(10.dp))

                Row(
                    horizontalArrangement = Arrangement.Center,
                    verticalAlignment = Alignment.CenterVertically
                ) {
                    Text(
                        text = "Нет аккаунта?",
                        fontSize = 12.sp,
                        color = Color(0xFF6C7278)
                    )
                    Text(
                        text = "Регистрация",
                        fontSize = 12.sp,
                        fontWeight = FontWeight.Bold,
                        color = Color(0xFF4D81E7),
                        modifier = Modifier
                            .padding(start = 6.dp)
                            .clickable(onClick = onSignUpClick)
                    )
                }

                Spacer(modifier = Modifier.height(20.dp))

                LabeledTextField(
                    label = "Email",
                    value = email,
                    onValueChange = {
                        email = it
                        emailError = null
                    },
                    placeholder = "primer@gmail.com",
                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Email),
                    errorText = emailError
                )

                Spacer(modifier = Modifier.height(12.dp))

                Column(modifier = Modifier.fillMaxWidth()) {
                    Text(
                        text = "Пароль",
                        fontSize = 12.sp,
                        color = Color(0xFF6C7278),
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    OutlinedTextField(
                        value = password,
                        onValueChange = {
                            password = it
                            passwordError = null
                        },
                        modifier = Modifier.fillMaxWidth(),
                        placeholder = { Text("Введите пароль", color = Color.Black.copy(alpha = 0.55f)) },
                        shape = RoundedCornerShape(10.dp),
                        singleLine = true,
                        visualTransformation = if (passwordVisible) VisualTransformation.None else PasswordVisualTransformation(),
                        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Password),
                        isError = passwordError != null,
                        trailingIcon = {
                            IconButton(onClick = { passwordVisible = !passwordVisible }) {
                                Icon(
                                    imageVector = if (passwordVisible) Icons.Default.Visibility else Icons.Default.VisibilityOff,
                                    contentDescription = if (passwordVisible) "Скрыть пароль" else "Показать пароль",
                                    tint = Color.Gray
                                )
                            }
                        },
                        colors = textFieldColors()
                    )
                    if (passwordError != null) {
                        Text(
                            text = passwordError.orEmpty(),
                            color = MaterialTheme.colorScheme.error,
                            fontSize = 12.sp,
                            modifier = Modifier.padding(top = 4.dp)
                        )
                    }
                }

                Spacer(modifier = Modifier.height(24.dp))

                Button(
                    onClick = {
                        emailError = validateLoginEmail(email)
                        passwordError = validateRequired(password, "Введите пароль.")
                    },
                    modifier = Modifier
                        .fillMaxWidth()
                        .height(50.dp),
                    shape = RoundedCornerShape(12.dp),
                    colors = ButtonDefaults.buttonColors(containerColor = Color(0xFF1D61E7))
                ) {
                    Text(text = "Войти", fontSize = 15.sp)
                }
            }
        }
    }
}

private fun validateLoginEmail(email: String): String? {
    if (email.trim().isEmpty()) return "Введите email."
    if (!email.contains("@")) return "Email должен содержать символ @."
    return null
}
Sign:
package com.example.signuplogininv4

import android.app.DatePickerDialog
import android.content.Intent
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.KeyboardOptions
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.DateRange
import androidx.compose.material.icons.filled.Visibility
import androidx.compose.material.icons.filled.VisibilityOff
import androidx.compose.material3.Button
import androidx.compose.material3.ButtonDefaults
import androidx.compose.material3.Card
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedTextField
import androidx.compose.material3.OutlinedTextFieldDefaults
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.res.vectorResource
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.input.KeyboardType
import androidx.compose.ui.text.input.PasswordVisualTransformation
import androidx.compose.ui.text.input.VisualTransformation
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import java.util.Calendar

class SignUp : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            SignUpScreen(
                onRegisterSuccess = { email, password ->
                    startActivity(
                        Intent(this, LoginIn::class.java).apply {
                            putExtra(LoginIn.EXTRA_EMAIL, email)
                            putExtra(LoginIn.EXTRA_PASSWORD, password)
                        }
                    )
                },
                onLoginClick = {
                    startActivity(Intent(this, LoginIn::class.java))
                }
            )
        }
    }
}

@Composable
fun SignUpScreen(
    onRegisterSuccess: (String, String) -> Unit,
    onLoginClick: () -> Unit
) {
    var login by remember { mutableStateOf("") }
    var email by remember { mutableStateOf("") }
    var birthDate by remember { mutableStateOf("") }
    var password by remember { mutableStateOf("") }
    var confirmPassword by remember { mutableStateOf("") }

    var loginError by remember { mutableStateOf<String?>(null) }
    var emailError by remember { mutableStateOf<String?>(null) }
    var birthDateError by remember { mutableStateOf<String?>(null) }
    var passwordError by remember { mutableStateOf<String?>(null) }
    var confirmPasswordError by remember { mutableStateOf<String?>(null) }

    var passwordVisible by remember { mutableStateOf(false) }
    var confirmPasswordVisible by remember { mutableStateOf(false) }
    val context = LocalContext.current

    val gradient = Brush.linearGradient(
        colors = listOf(Color(0xFF2473E6), Color(0xFF1CE0DA)),
        start = Offset.Zero,
        end = Offset.Infinite
    )

    val calendar = Calendar.getInstance()
    val datePicker = DatePickerDialog(
        context,
        { _, year, month, dayOfMonth ->
            birthDate = "%02d.%02d.%d".format(dayOfMonth, month + 1, year)
            birthDateError = null
        },
        calendar.get(Calendar.YEAR),
        calendar.get(Calendar.MONTH),
        calendar.get(Calendar.DAY_OF_MONTH)
    )

    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(gradient)
            .verticalScroll(rememberScrollState())
            .padding(horizontal = 16.dp, vertical = 24.dp),
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        LogoHeader()
        Spacer(modifier = Modifier.height(20.dp))

        Card(
            modifier = Modifier.fillMaxWidth(),
            shape = RoundedCornerShape(24.dp)
        ) {
            Column(
                modifier = Modifier
                    .fillMaxWidth()
                    .background(Color.White)
                    .padding(horizontal = 24.dp, vertical = 28.dp),
                horizontalAlignment = Alignment.CenterHorizontally
            ) {
                Text(
                    text = "Регистрация",
                    fontSize = 36.sp,
                    fontWeight = FontWeight.Bold,
                    color = Color(0xFF111827)
                )

                Spacer(modifier = Modifier.height(10.dp))

                Row(verticalAlignment = Alignment.CenterVertically) {
                    Text(
                        text = "Уже есть аккаунт?",
                        fontSize = 12.sp,
                        color = Color(0xFF6C7278)
                    )
                    Text(
                        text = "Вход",
                        fontSize = 12.sp,
                        fontWeight = FontWeight.Bold,
                        color = Color(0xFF4D81E7),
                        modifier = Modifier
                            .padding(start = 6.dp)
                            .clickable(onClick = onLoginClick)
                    )
                }

                Spacer(modifier = Modifier.height(20.dp))

                LabeledTextField(
                    label = "Логин",
                    value = login,
                    onValueChange = {
                        login = it
                        loginError = null
                    },
                    placeholder = "loginperson",
                    errorText = loginError
                )

                Spacer(modifier = Modifier.height(12.dp))

                LabeledTextField(
                    label = "Email",
                    value = email,
                    onValueChange = {
                        email = it
                        emailError = null
                    },
                    placeholder = "primer@gmail.com",
                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Email),
                    errorText = emailError
                )

                Spacer(modifier = Modifier.height(12.dp))

                DateField(
                    label = "Дата рождения",
                    value = birthDate,
                    placeholder = "18.03.2003",
                    errorText = birthDateError,
                    onClick = { datePicker.show() }
                )

                Spacer(modifier = Modifier.height(12.dp))

                PasswordField(
                    label = "Пароль",
                    value = password,
                    onValueChange = {
                        password = it.filter(Char::isDigit)
                        passwordError = null
                    },
                    placeholder = "12345678",
                    isVisible = passwordVisible,
                    onToggleVisibility = { passwordVisible = !passwordVisible },
                    errorText = passwordError
                )

                Spacer(modifier = Modifier.height(12.dp))

                PasswordField(
                    label = "Повторите пароль",
                    value = confirmPassword,
                    onValueChange = {
                        confirmPassword = it.filter(Char::isDigit)
                        confirmPasswordError = null
                    },
                    placeholder = "12345678",
                    isVisible = confirmPasswordVisible,
                    onToggleVisibility = { confirmPasswordVisible = !confirmPasswordVisible },
                    errorText = confirmPasswordError
                )

                Spacer(modifier = Modifier.height(24.dp))

                Button(
                    onClick = {
                        loginError = validateLogin(login)
                        emailError = validateRegistrationEmail(email)
                        birthDateError = validateRequired(birthDate, "Укажите дату рождения.")
                        passwordError = validateRegistrationPassword(password)
                        confirmPasswordError = validatePasswordConfirmation(password, confirmPassword)

                        val isValid = listOf(
                            loginError,
                            emailError,
                            birthDateError,
                            passwordError,
                            confirmPasswordError
                        ).all { it == null }

                        if (isValid) {
                            onRegisterSuccess(email.trim(), password)
                        }
                    },
                    modifier = Modifier
                        .fillMaxWidth()
                        .height(50.dp),
                    shape = RoundedCornerShape(12.dp),
                    colors = ButtonDefaults.buttonColors(containerColor = Color(0xFF1D61E7))
                ) {
                    Text(text = "Зарегистрироваться", fontSize = 15.sp)
                }
            }
        }
    }
}

@Composable
fun LogoHeader() {
    Row(
        modifier = Modifier.padding(top = 16.dp),
        verticalAlignment = Alignment.CenterVertically,
        horizontalArrangement = Arrangement.Center
    ) {
        Icon(
            imageVector = ImageVector.vectorResource(R.drawable.vector),
            contentDescription = null,
            tint = Color.White
        )
        Spacer(modifier = Modifier.width(8.dp))
        Text(
            text = "Logoipsum",
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold,
            color = Color.White
        )
    }
}

@Composable
fun LabeledTextField(
    label: String,
    value: String,
    onValueChange: (String) -> Unit,
    placeholder: String,
    keyboardOptions: KeyboardOptions = KeyboardOptions.Default,
    errorText: String? = null
) {
    Column(modifier = Modifier.fillMaxWidth()) {
        Text(
            text = label,
            fontSize = 12.sp,
            color = Color(0xFF6C7278),
            modifier = Modifier.padding(bottom = 4.dp)
        )
        OutlinedTextField(
            value = value,
            onValueChange = onValueChange,
            modifier = Modifier.fillMaxWidth(),
            placeholder = { Text(placeholder, color = Color.Black.copy(alpha = 0.55f)) },
            shape = RoundedCornerShape(10.dp),
            keyboardOptions = keyboardOptions,
            isError = errorText != null,
            singleLine = true,
            colors = textFieldColors()
        )
        if (errorText != null) {
            Text(
                text = errorText,
                color = MaterialTheme.colorScheme.error,
                fontSize = 12.sp,
                modifier = Modifier.padding(top = 4.dp)
            )
        }
    }
}

@Composable
fun PasswordField(
    label: String,
    value: String,
    onValueChange: (String) -> Unit,
    placeholder: String,
    isVisible: Boolean,
    onToggleVisibility: () -> Unit,
    errorText: String?
) {
    Column(modifier = Modifier.fillMaxWidth()) {
        Text(
            text = label,
            fontSize = 12.sp,
            color = Color(0xFF6C7278),
            modifier = Modifier.padding(bottom = 4.dp)
        )
        OutlinedTextField(
            value = value,
            onValueChange = onValueChange,
            modifier = Modifier.fillMaxWidth(),
            placeholder = { Text(placeholder, color = Color.Black.copy(alpha = 0.55f)) },
            shape = RoundedCornerShape(10.dp),
            singleLine = true,
            visualTransformation = if (isVisible) VisualTransformation.None else PasswordVisualTransformation(),
            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.NumberPassword),
            isError = errorText != null,
            trailingIcon = {
                IconButton(onClick = onToggleVisibility) {
                    Icon(
                        imageVector = if (isVisible) Icons.Default.Visibility else Icons.Default.VisibilityOff,
                        contentDescription = if (isVisible) "Скрыть пароль" else "Показать пароль",
                        tint = Color.Gray
                    )
                }
            },
            colors = textFieldColors()
        )
        if (errorText != null) {
            Text(
                text = errorText,
                color = MaterialTheme.colorScheme.error,
                fontSize = 12.sp,
                modifier = Modifier.padding(top = 4.dp)
            )
        }
    }
}

@Composable
fun DateField(
    label: String,
    value: String,
    placeholder: String,
    errorText: String?,
    onClick: () -> Unit
) {
    Column(modifier = Modifier.fillMaxWidth()) {
        Text(
            text = label,
            fontSize = 12.sp,
            color = Color(0xFF6C7278),
            modifier = Modifier.padding(bottom = 4.dp)
        )
        Box(
            modifier = Modifier
                .fillMaxWidth()
                .clip(RoundedCornerShape(10.dp))
                .clickable(onClick = onClick)
        ) {
            OutlinedTextField(
                value = value,
                onValueChange = {},
                modifier = Modifier.fillMaxWidth(),
                placeholder = { Text(placeholder, color = Color.Black.copy(alpha = 0.55f)) },
                shape = RoundedCornerShape(10.dp),
                enabled = false,
                isError = errorText != null,
                trailingIcon = {
                    Icon(
                        imageVector = Icons.Default.DateRange,
                        contentDescription = "Выбрать дату",
                        tint = Color.Gray
                    )
                },
                colors = textFieldColors()
            )
        }
        if (errorText != null) {
            Text(
                text = errorText,
                color = MaterialTheme.colorScheme.error,
                fontSize = 12.sp,
                modifier = Modifier.padding(top = 4.dp)
            )
        }
    }
}

@Composable
fun textFieldColors() = OutlinedTextFieldDefaults.colors(
    focusedBorderColor = Color(0xFF928787),
    unfocusedBorderColor = Color(0xFF928787),
    disabledBorderColor = Color(0xFF928787),
    disabledTextColor = Color.Black,
    disabledPlaceholderColor = Color.Black.copy(alpha = 0.55f),
    errorBorderColor = MaterialTheme.colorScheme.error,
    errorTrailingIconColor = MaterialTheme.colorScheme.error
)

fun validateRequired(value: String, message: String): String? {
    return if (value.trim().isEmpty()) message else null
}

fun validateLogin(login: String): String? {
    if (login.trim().isEmpty()) return "Введите логин."
    if (login.trim().length < 8) return "Логин должен содержать не менее 8 символов."
    return null
}

fun validateRegistrationEmail(email: String): String? {
    if (email.trim().isEmpty()) return "Введите email."
    if (email.trim().length < 12) return "Email должен содержать не менее 12 символов."
    if (!email.contains("@")) return "Email должен содержать символ @."
    return null
}

fun validateRegistrationPassword(password: String): String? {
    if (password.isEmpty()) return "Введите пароль."
    if (!password.all(Char::isDigit)) return "Пароль должен состоять только из цифр."
    if (password.length < 8) return "Пароль должен содержать не менее 8 цифр."
    return null
}

fun validatePasswordConfirmation(password: String, confirmation: String): String? {
    if (confirmation.isEmpty()) return "Повторите пароль."
    if (confirmation != password) return "Пароли должны совпадать."
    return null
}