:root {
    /* Color palette */
    --color-primary: #16222a;
    --color-secondary: #3a6073;
    --color-accent: teal;
    --color-accent-hover: purple;
    --color-highlight: yellow;
    --color-text: white;
    --color-text-secondary: #e0e0e0;
    --color-shadow: rgba(0, 0, 0, 0.2);

    /* Typography */
    --font: cursive;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;

    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 30px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    line-height: 1.75;
    font-size: 18px;
}

body {
    min-height: 100dvh;
    text-rendering: optimizeLegibility;
    background: linear-gradient(to right, var(--color-primary), var(--color-secondary));
    color: var(--color-text);
    text-align: center;
    font-family: var(--font);
    text-wrap: balance;
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
}

h1,
h2,
h3 {
    margin-bottom: var(--space-md);
}

h1 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    margin-bottom: var(--space-lg);
}

h2 {
    font-size: clamp(1.25rem, 4vw, 1.75rem);
}

p {
    margin-bottom: var(--space-md);
    font-size: clamp(0.9rem, 3vw, 1rem);
    font-family: sans-serif;
}

/* Layout */
header {
    margin-bottom: var(--space-xl);
    padding: var(--space-md);
}

main {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-xl);
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    flex: 1;
}

footer {
    margin-top: var(--space-xl);
    padding: var(--space-lg) var(--space-md);
    font-size: 0.9rem;
}

footer a {
    color: var(--color-text);
    text-decoration: none;
    border-bottom: 1px solid var(--color-accent);
    padding: var(--space-xs);
    transition: color var(--transition-fast);

    &:hover {
        color: var(--color-highlight);
    }
}

/* Calculator cards */
.calculator-card {
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    box-shadow: 0 4px 6px var(--color-shadow);
    backdrop-filter: blur(5px);
    transition: transform var(--transition-normal);
    display: flex;
    flex-direction: column;
    height: 100%;

    &:hover {
        transform: translateY(-5px);
    }
}

/* Forms */
form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    margin-top: auto;
}

.form-group {
    display: flex;
    flex-direction: column;
    text-align: left;
    gap: var(--space-xs);
}

label {
    font-weight: bold;
    margin-bottom: var(--space-xs);
}

input,
select,
textarea {
    padding: var(--space-sm);
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background-color: var(--color-text);
    color: var(--color-primary);
    transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--color-accent);
    background-color: rgba(255, 255, 255, 0.2);
}

input::placeholder,
textarea::placeholder {
    color:var(--color-primary);
}

.days-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-xs) var(--space-md);
    align-items: center;
}

.form-text {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    font-style: italic;
}

/* Buttons */
button {
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-highlight);
    border-radius: var(--radius-lg);
    background-color: var(--color-accent);
    color: var(--color-text);
    font-size: 1rem;
    cursor: pointer;
    transition: background-color var(--transition-fast), transform var(--transition-fast);
    text-transform: capitalize;

    &:hover,
    &:focus {
        background-color: var(--color-accent-hover);
        transform: scale(1.05);
    }

    &:active {
        transform: scale(0.98);
    }
}

.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
}

/* Results display */
.result-display {
    margin-top: var(--space-md);
    min-height: 2rem;
    padding: var(--space-sm);
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    font-weight: bold;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.result-display.active {
    opacity: 1;
}


/* Responsive adjustments */
@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
    }

    .button-group {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }

    .calculator-card {
        padding: var(--space-md);
    }

    form {
        gap: var(--space-sm);
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    * {
        transform: none;
        animation: none;
        transition: none;
    }
}