:root {
    --dark-bg: #111;
    --card-bg: #1a1a1a;
    --input-bg: #2a2a2a;
    --border-color: #333;
    --text-color: #e0e0e0;
    --text-muted: #888;
    --accent-color: #7DFF26; /* lime-400 */
    --error-color: #f87171; /* red-400 */
    --protein-color: #38bdf8; /* sky-400 */
    --fat-color: #facc15; /* amber-400 */
    --carbs-color: #f43f5e; /* rose-500 */
}

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

body {
    font-family: 'Montserrat', sans-serif;
    background-color: var(--dark-bg);
    color: var(--text-color);
    font-weight: 700;
    font-style: italic;
    padding: 2rem;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

h1, h2, h3 {
    font-weight: 900;
}

.container {
    width: 100%;
    max-width: 800px;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 3rem;
    text-transform: uppercase;
    color: var(--accent-color);
    letter-spacing: 0.05em;
    text-shadow: 0 0 10px rgba(163, 230, 53, 0.3);
}

header p {
    color: var(--text-muted);
    font-size: 1.125rem;
    margin-top: 0.5rem;
}

/* Nouvelle carte d'explication */
.explanation-card {
    background-color: rgba(26, 26, 26, 0.6);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent-color);
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text-muted);
}

.explanation-card h3 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.explanation-card p{
    margin-bottom: 1rem;
}

.explanation-card .highlight {
    color: var(--accent-color);
    font-style: normal;
}

.calculator {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(163, 230, 53, 0.1);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.form-group.span-2 {
    grid-column: span 2;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-color);
}

input[type="number"],
select {
    width: 100%;
    background-color: var(--input-bg);
    color: var(--text-color);
    padding: 0.75rem;
    border-radius: 0.5rem;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-style: italic;
    font-size: 1rem;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(163, 230, 53, 0.4);
}

input::placeholder {
    color: var(--text-muted);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%23a3e635' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

.gender-options {
    display: flex;
    gap: 1rem;
}

.gender-options input[type="radio"] {
    display: none;
}

.gender-options label {
    flex-grow: 1;
    text-align: center;
    padding: 0.75rem;
    border-radius: 0.5rem;
    border: 2px solid var(--border-color);
    background-color: var(--input-bg);
    cursor: pointer;
    transition: all 0.3s ease;
}

.gender-options label:hover {
    border-color: var(--accent-color);
}

.gender-options input[type="radio"]:checked + label {
    background-color: var(--accent-color);
    color: var(--dark-bg);
    border-color: var(--accent-color);
}

button {
    width: 100%;
    background-color: var(--accent-color);
    color: var(--dark-bg);
    font-size: 1.25rem;
    padding: 1rem;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(163, 230, 53, 0.2);
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    font-style: italic;
    margin-top: 1rem;
}

button:hover {
    background-color: #bbf7d0; /* lime-200 */
    transform: scale(1.02);
    box-shadow: 0 8px 20px rgba(163, 230, 53, 0.3);
}

.error-message {
    color: var(--error-color);
    text-align: center;
    height: 1.5rem; /* Reserve space */
    margin-top: 0.5rem;
    font-size: 0.875rem;
}

.results-container {
    margin-top: 2.5rem;
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(163, 230, 53, 0.1);
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.results-container h2 {
    text-align: center;
    font-size: 2rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.calories-summary {
    /* Changed from grid to flex for single item centering */
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
    text-align: center;
}

.calories-summary .card {
    background-color: var(--dark-bg);
    padding: 1.5rem;
    border-radius: 0.75rem;
    /* Make the single card wider */
    width: 100%;
    max-width: 400px;
    border: 1px solid var(--border-color);
}

.calories-summary h3 {
    font-size: 1rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.calories-summary .value {
    font-size: 3.5rem; /* slightly bigger since it's the main focus now */
    color: var(--accent-color);
    margin-top: 0.5rem;
}

.calories-summary .value span {
    font-size: 1.5rem;
    color: var(--text-muted);
}

.calories-summary p {
    font-size: 0.875rem;
    color: #666;
    margin-top: 0.5rem;
}

.macros-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.macros-breakdown .card {
    background-color: var(--input-bg);
    padding: 1rem;
    border-radius: 0.75rem;
    text-align: center;
}

.macros-breakdown .card.protein { border-bottom: 4px solid var(--protein-color); }
.macros-breakdown .card.fat { border-bottom: 4px solid var(--fat-color); }
.macros-breakdown .card.carbs { border-bottom: 4px solid var(--carbs-color); }

.macros-breakdown h3 {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.macros-breakdown .grams {
    font-size: 1.5rem;
    margin: 0.25rem 0;
}

.macros-breakdown .calories {
    font-size: 1rem;
    color: var(--text-muted);
}

footer {
    text-align: center;
    color: #555;
    margin-top: 2.5rem;
    margin-bottom: 2rem;
    font-size: 0.875rem;
}

@media (max-width: 640px) {
    body { padding: 1rem; }
    header h1 { font-size: 2.25rem; }
    .calculator, .results-container { padding: 1.5rem; }
    .calculator { grid-template-columns: 1fr; }
    .form-group.span-2 { grid-column: span 1; }
}