/* ============================================
   CSS: CALCULADORA DE IMC
   Mobile-First Responsive Design
   ============================================ */

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

:root {
    --primary-color: #2C3E50;
    --secondary-color: #3498DB;
    --success-color: #27AE60;
    --warning-color: #F39C12;
    --danger-color: #E74C3C;
    --light-bg: #ECF0F1;
    --border-radius: 8px;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 15px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--primary-color);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 40px 30px;
    max-width: 500px;
    width: 100%;
}

h1 {
    text-align: center;
    font-size: 28px;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.subtitle {
    text-align: center;
    color: #7F8C8D;
    font-size: 14px;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--primary-color);
    font-size: 14px;
}

input[type="number"] {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--light-bg);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: all 0.3s ease;
    background: #FAFAFA;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--secondary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

input[type="number"]::placeholder {
    color: #95A5A6;
}

.input-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 20px;
}

.input-wrapper .form-group {
    margin-bottom: 0;
}

.button-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin: 30px 0;
}

button {
    padding: 12px 20px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-calculate {
    background: var(--secondary-color);
    color: white;
    grid-column: span 2;
}

.btn-calculate:hover {
    background: #2980B9;
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.btn-calculate:active {
    transform: translateY(0);
}

.btn-clear {
    background: var(--light-bg);
    color: var(--primary-color);
    border: 2px solid #BDC3C7;
}

.btn-clear:hover {
    background: #D5DBDB;
    border-color: #95A5A6;
}

.error-message {
    display: none;
    background: #FADBD8;
    color: #A93226;
    padding: 12px 15px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--danger-color);
    margin-bottom: 20px;
    font-size: 14px;
    font-weight: 500;
}

.error-message.show {
    display: block;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-card {
    display: none;
    margin-top: 30px;
    padding: 25px;
    border-radius: var(--border-radius);
    background: #F8F9FA;
    border-left: 5px solid var(--secondary-color);
    animation: slideIn 0.3s ease;
}

.result-card.show {
    display: block;
}

.result-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 15px;
}

.result-value {
    font-size: 32px;
    font-weight: bold;
    color: var(--primary-color);
}

.result-emoji {
    font-size: 36px;
}

.result-category {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 15px;
    padding: 12px 15px;
    border-radius: var(--border-radius);
    text-align: center;
    color: white;
}

.result-category.normal {
    background: var(--success-color);
}

.result-category.warning {
    background: var(--warning-color);
}

.result-category.danger {
    background: var(--danger-color);
}

.result-range {
    background: white;
    padding: 15px;
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid #E8E8E8;
}

.result-range-label {
    font-size: 12px;
    color: #7F8C8D;
    text-transform: uppercase;
    margin-bottom: 5px;
    letter-spacing: 0.5px;
}

.result-range-value {
    font-size: 16px;
    font-weight: 600;
    color: var(--success-color);
}

@media (min-width: 600px) {
    .container {
        padding: 50px 40px;
    }

    h1 {
        font-size: 32px;
    }

    .input-wrapper {
        grid-template-columns: 1fr 1fr;
    }

    button {
        padding: 14px 24px;
        font-size: 16px;
    }
}

button:focus {
    outline: 2px solid var(--secondary-color);
    outline-offset: 2px;
}

input:focus {
    outline: none;
}

.text-center {
    text-align: center;
}

.mt-2 {
    margin-top: 10px;
}