:root {
    --main-background-color: #F8F9FA;
    --main-text-color: #333333;

    --header-background-color: linear-gradient(to bottom, #ffffff, #f2f2f2);;
    --header-box-shadow: 0px 4px 8px rgba(0, 0, 0, 0.1);
    --header-color: #37474F;

    --subtle-background-color: #FFFFFF;
    --subtle-border-color: #3A3A3A;

    --primary-background-color: #1E88E5;
    --primary-background-hover-color: #42a5f5;
    --primary-background-active-color: #1c74c2;
    --primary-focus-box-shadow: 0px 0px 4px rgba(100, 181, 246, 0.5);;
    --primary-focus-border-color: #64B5F6;
    --primary-button-color: #FFFFFF;
    --secondary-text-color: #888888;
    --error-text-color: #E53935;
}

@media (prefers-color-scheme: dark) {
    :root {
        --main-background-color: #121212;
        --main-text-color: #D3D3D3;

        --header-background-color: #1E1E1E;
        --header-box-shadow:  0px 2px 4px rgba(0, 0, 0, 0.1);;
        --header-color: #E0E0E0;

        --subtle-background-color: #2C2C2C;
        --subtle-border-color: #E0E0E0;

        --primary-background-color: #2962FF;
        --primary-background-hover-color: #1e54b4;
        --primary-background-active-color: #1a47a0;
        --primary-focus-box-shadow: 0px 0px 4px rgba(100, 181, 246, 0.5);
        --primary-focus-border-color: #64B5F6;
        --primary-button-color: #FFFFFF;
        --secondary-text-color: #B0B0B0; 
        --error-text-color: #E57373;
    } 
}

*, *::after, *::before {
    box-sizing: border-box;
}

html {
    font-family: 'Inter', sans-serif;
    font-optical-sizing: auto;
}

html,
body {
    color: var(--main-text-color);
    padding: 0;
    margin: 0;
}

body {
    background-color: var(--main-background-color);
}

main {
    max-width: 820px;
    width: 100%;
    margin: 0 auto;
    padding: 0 24px;
}

header {
    display: flex;
    align-items: center;
    padding: 16px;
    height: 80px;
    background: var(--header-background-color);
    box-shadow: var(--header-box-shadow);
    margin-bottom: 24px;
}

.title {
    font-size: 2rem;
    font-weight: 700;
    font-family: 'Inter', sans-serif;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.05);
    color: var(--header-color);
}

textarea,
button,
input {
    font-family: inherit;
    color: inherit;
}

.label-text {
    display: inline-block;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
}

.v-label .label-text {
    margin-bottom: 4px;
}

.h-label .label-text {
    margin-right: 8px;
}

.textarea {
    width: 100%;
    font-family: 'Inter', sans-serif;
    min-height: 280px;
    max-height: 440px;
    background-color: var(--subtle-background-color);
    color: inherit;
    resize: vertical;
    border: 1px solid var(--subtle-border-color);
    padding: 12px;
    border-radius: 6px;
    font-size: 1rem;
    line-height: 1.4;
    outline: none;
    margin-bottom: 16px;
}

.textarea:focus {
    border-color: var(--primary-background-color);
}

.form-bottom {
    display: flex;
    align-items: center;
    gap: 0 24px;
    margin-bottom: 24px;
}

.input {
    height: 50px;
    padding: 0 12px;
    background-color: var(--subtle-background-color);
    color: inherit;
    border-radius: 6px;
    border: 1px solid var(--subtle-border-color);
    outline: none;
    font-size: 1rem;
}

.input:focus {
    border-color: var(--primary-background-color);
}

.btn {
    font-weight: 700;
    width: 100%;
    max-width: 240px;
    height: 50px;
    padding: 12px 24px;
    background-color: var(--primary-background-color);
    border-radius: 6px;
    border: none;
    color: var(--primary-button-color);
    transition: transform .3s ease-in-out;
    font-size: 1rem;
    letter-spacing: .5px;
}

.btn:hover {
    background-color: var(--primary-background-hover-color);
}

.btn:active {
    background-color: var(--primary-background-active-color);
    transform: scale(.98);
}

.btn:focus {
    box-shadow: var(--primary-focus-box-shadow);
    border: 2px solid var(--primary-focus-border-color);
}

#result {
    max-height: 440px;
    margin-top: 24px;
    border-radius: 6px;
    background-color: var(--subtle-background-color);
    border-color: var(--subtle-border-color);
    padding: 12px;
    border: 1px solid var(--subtle-border-color);
    line-height: 1.4;
}

#result ul {
    font-weight: 700;
    list-style-type: none;
    margin: 0;
    padding: 0;
}

.placeholder {
    font-size: 1rem;
    color: var(--secondary-text-color);
}

.error {
    color: var(--error-text-color);
}