/*
* Filename: styles.css
* Purpose: Style sheet for the EMS Medication Dose Calculator
* Author: papaTypes
* Date: 2026-01-30
* Version: 1.0.0
*/

/* =================================================== 
   CSS RESET 
=================================================== */
* {
    margin-block: 0;
    margin-inline: 0;
    padding-block: 0;
    padding-inline: 0;
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
}

button {
    font-family: inherit;
    cursor: pointer;
}

input {
    font-family: inherit;
}

/* =================================================== 
   CUSTOM PROPERTIES (DESIGN TOKENS) 
=================================================== */
:root {
    /* Colors */
    --bg-page: #0a0a0a;
    --bg-calculator: rgba(0, 0, 0, 0.6);
    --bg-input: rgba(0, 0, 0, 0.4);
    
    --text-primary: #ffffff;
    --text-inactive: #d2d2d2;
    
    --accent-red: #d32f2f;
    --accent-red-hover: #e63946;
    
    --border-red: #d32f2f;
    
    /* Spacing */
    --spacing-xxs: 0.25rem;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    
    /* Borders */
    --radius-md: 0.5rem;
    
    /* Effects */
    --transition-normal: 0.3s ease;
}

/* =================================================== 
   BASE STYLES 
=================================================== */
body {
    background-color: var(--bg-page);
    color: var(--text-primary);
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: var(--spacing-md);
}

main {
    max-inline-size: 100%;
    width: 100%;
    background: linear-gradient(135deg, #2a2a2a 0%, #0a0a0a 100%);
    backdrop-filter: blur(0.625rem);
    border: 3px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
    padding-block: var(--spacing-md);
    padding-inline: var(--spacing-md);
}

/* =================================================== 
   HEADER 
=================================================== */
header {
    margin-block-end: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding-block: var(--spacing-sm);
    padding-inline: var(--spacing-sm);
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-block-end: 0.5rem;
}

header p {
    font-size: 0.875rem;
    text-align: center;
    opacity: 0.7;
}

/* =================================================== 
   CALCULATOR CONTAINER 
=================================================== */
.calculator {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* =================================================== 
   FORM CONTAINER (LIFTED) 
=================================================== */
.form-container {
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

/* =================================================== 
   MODE TOGGLE 
=================================================== */
.mode-toggle {
    display: flex;
    gap: var(--spacing-xs);
    margin-block-end: var(--spacing-md);
}

.toggle-button {
    flex: 1;
    padding-block: var(--spacing-xs);
    padding-inline: var(--spacing-sm);
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-inactive);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    font-weight: 500;
}

.toggle-button.active {
    background-color: var(--accent-red);
    color: var(--text-primary);
    border-color: var(--accent-red);
}

.toggle-button:hover {
    background-color: #ffffff;
    color: #1a1a1a;
    border-color: #ffffff;
}

/* =================================================== 
   UNIT SELECTOR 
=================================================== */
fieldset {
    margin-block-end: var(--spacing-md);
    border: none;
    padding: 0;
}

legend {
    display: block;
    margin-block-end: var(--spacing-xs);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.unit-buttons {
    display: flex;
    gap: var(--spacing-xs);
}

fieldset label {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-block: var(--spacing-xs);
    padding-inline: var(--spacing-md);
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    font-weight: 500;
}

fieldset label:has(input:checked) {
    background-color: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
}

fieldset label:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

fieldset input[type="radio"] {
    display: none;
}

/* =================================================== 
   FORM INPUTS 
=================================================== */

.calculator-input-desired-dose,
.calculator-input-concentration,
.calculator-input-weight {
    margin-block-end: var(--spacing-md);
}

/* Labels */
.calculator-input-desired-dose label,
.calculator-input-concentration label,
.calculator-input-weight label {
    display: block;
    margin-block-end: var(--spacing-xs);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Input Wrapper - Contains input + unit suffix */
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

/* Number Inputs */
input[type="number"] {
    flex: 1;
    padding-block: var(--spacing-sm);
    padding-inline-start: var(--spacing-sm);
    padding-inline-end: 3.5rem;
    background-color: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    font-size: 1.125rem;
    font-weight: 500;
}

input[type="number"]:focus {
    outline: 2px solid var(--accent-red);
    outline-offset: 2px;
    border-color: var(--accent-red);
}

/* Hide number input spinners */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    -moz-appearance: textfield;
}

/* Unit Suffix - Grey text inside input */
.unit-suffix {
    position: absolute;
    right: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.35);
    font-size: 0.875rem;
    font-weight: 500;
    pointer-events: none;
    user-select: none;
}

/* Concentration Group - Mass / Volume layout */
.concentration-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.concentration-group .input-wrapper {
    flex: 1;
}

.separator {
    color: rgba(255, 255, 255, 0.5);
    font-size: 1.25rem;
    font-weight: 300;
}

/* =================================================== 
   CALCULATE BUTTON 
=================================================== */
.calculate-button {
    width: 100%;
    padding-block: var(--spacing-sm);
    padding-inline: var(--spacing-md);
    background-color: var(--accent-red);
    color: var(--text-primary);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    margin-block-start: var(--spacing-sm);
}

.calculate-button:hover {
    background-color: #ffffff;
    color: #1a1a1a;
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
    transform: translateY(-1px);
}

/* =================================================== 
   RESET BUTTON 
=================================================== */
.reset-button {
    width: 100%;
    padding-block: var(--spacing-sm);
    padding-inline: var(--spacing-md);
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-inactive);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    transition: all var(--transition-normal);
    margin-block-start: var(--spacing-xs);
}

.reset-button:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
}

/* =================================================== 
   RESULTS 
=================================================== */
.results-container {
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.results-container h2 {
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-block-end: var(--spacing-xs);
    opacity: 0.5;
}

.final-result {
    margin-block-end: var(--spacing-sm);
}

.result-value {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}

.calculation-steps {
    font-size: 0.875rem;
    opacity: 0.7;
    line-height: 1.6;
}

.calculation-steps p {
    margin: 0;
}

/* =================================================== 
   UTILITY CLASSES 
=================================================== */
.hidden {
    display: none;
}


/* =================================================== 
   MOBILE RESPONSIVE 
=================================================== */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-xs);
    }
    
    main {
        padding-block: var(--spacing-sm);
        padding-inline: var(--spacing-sm);
    }
    
    h1 {
        font-size: 1.25rem;
    }
    
    header p {
        font-size: 0.8rem;
    }
    
    input[type="number"] {
        font-size: 16px;
    }
    
    .concentration-group {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .separator {
        display: none;
    }
    
    .result-value {
        font-size: 2rem;
    }
}