:root {
    --brand-green: #8DC63F;
    --brand-blue: #124962;
    --brand-blue-light: #1A627B;
    
    --bg-color: #F4F7F6;
    --card-bg: #FFFFFF;
    --text-main: #124962;
    --text-muted: #64748B;
    --border-color: #E2E8F0;
    --input-bg: #F8FAFC;
    --shadow: 0 10px 25px -5px rgba(18, 73, 98, 0.08), 0 8px 10px -6px rgba(18, 73, 98, 0.04);
}

[data-theme="dark"] {
    --bg-color: #0B1120;
    --card-bg: rgba(30, 41, 59, 0.6);
    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
    --border-color: #334155;
    --input-bg: #1E293B;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
    --backdrop-blur: blur(16px);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s, transform 0.3s ease, box-shadow 0.3s ease;
}

/* Ocultar iconos de flechas en input number */
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;
}

h1, h2, h3, .logo { font-family: 'Inter', sans-serif; font-weight: 800; letter-spacing: -0.5px; }

body {
    background-color: transparent;
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem 1rem;
    overflow-x: hidden;
}

.hero-bg {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100vh;
    background-image: url('img/hero-bg.png');
    background-size: cover;
    background-position: center;
    z-index: -2;
    animation: slowPan 25s infinite alternate ease-in-out;
}

.hero-overlay {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100vh;
    background: rgba(11, 17, 32, 0.75);
    z-index: -1;
}

@keyframes slowPan {
    0% { transform: scale(1) translateX(0); }
    100% { transform: scale(1.1) translateX(-10px); }
}

.theme-toggle {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
}

#theme-btn {
    background: var(--card-bg);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header {
    text-align: center;
    margin-bottom: 2.5rem;
    margin-top: 1rem;
}

.logo {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -1.5px;
}

.logo-nutri { color: var(--brand-blue); }
[data-theme="dark"] .logo-nutri { color: #FFFFFF; }
.logo-paws { color: var(--brand-green); }

.stat-box.main-stat .value {
    color: var(--brand-green);
    font-size: 2.2rem;
}

/* Resplandor del Cursor Estilo Antigravity - Trail */
.cursor-trail-dot {
    position: fixed;
    width: 6px;
    height: 6px;
    background: var(--brand-green);
    border-radius: 50%;
    pointer-events: none;
    transform: translate(-50%, -50%);
    z-index: 9999;
    transition: transform 0.1s ease;
}

body.cursor-hover .cursor-trail-dot {
    transform: translate(-50%, -50%) scale(1.5);
    opacity: 0.5;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

.container {
    width: 100%;
    max-width: 600px;
}

.card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    backdrop-filter: var(--backdrop-blur, none);
}

.step {
    margin-bottom: 2.5rem;
    animation: fadeIn 0.4s ease-out;
}

.step h2 {
    font-size: 1.4rem;
    margin-bottom: 1.2rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.step-num {
    background: var(--brand-green);
    color: white;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: 1rem;
    font-weight: bold;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.radio-card input { display: none; }

.card-content {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.2rem;
    background: var(--input-bg);
    border: 2px solid var(--border-color);
    border-radius: 14px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.radio-card:hover .card-content {
    transform: translateY(-4px);
    box-shadow: 0 8px 15px rgba(141, 198, 63, 0.15);
    border-color: var(--brand-green);
}

.radio-card input:checked + .card-content {
    border-color: var(--brand-green);
    background: rgba(141, 198, 63, 0.08);
    color: var(--brand-green);
    box-shadow: 0 0 0 4px rgba(141, 198, 63, 0.15);
}

.form-group {
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
}

.age-group, .dose-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group label {
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.95rem;
}

.form-group select, .form-group input {
    padding: 1rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: var(--input-bg);
    color: var(--text-main);
    font-size: 1rem;
}

.form-group select:focus, .form-group input:focus {
    outline: none;
    border-color: var(--brand-green);
    box-shadow: 0 0 0 3px rgba(141, 198, 63, 0.2);
}

.btn-primary {
    width: 100%;
    padding: 1.2rem;
    background-color: var(--brand-green);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.15rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(141, 198, 63, 0.4);
}

.btn-primary:hover {
    background-color: #7ab335;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(141, 198, 63, 0.5);
}

.btn-secondary {
    width: 100%;
    padding: 1rem;
    background-color: transparent;
    color: var(--brand-blue);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}
[data-theme="dark"] .btn-secondary { color: white; }

.btn-emergency {
    position: fixed;
    top: 1.5rem;
    left: 1.5rem;
    z-index: 9999;
    background: #ef4444;
    color: white;
    padding: 0.8rem 1.5rem;
    font-size: 1.1rem;
    font-weight: bold;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.4);
    transition: transform 0.2s, background-color 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-emergency:hover {
    transform: translateY(-2px);
    background: #dc2626;
}

.result-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.summary-card {
    text-align: center;
    background: linear-gradient(135deg, var(--brand-blue), var(--brand-blue-light));
    color: white;
    border: none;
}

.summary-card h2 { color: white; opacity: 0.9; margin-bottom: 0.5rem; }

.summary-stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
}

.stat-box {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.stat-box.main-stat {
    grid-column: 1 / -1;
    background: rgba(255, 255, 255, 0.15);
    padding: 1.5rem;
}

.stat-label {
    font-size: 0.85rem;
    opacity: 0.85;
    margin-bottom: 0.4rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.stat-value {
    font-size: 1.4rem;
    font-weight: 700;
}

.main-stat .stat-value {
    font-size: 3.5rem;
    color: var(--brand-green);
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
    line-height: 1;
    margin-top: 0.2rem;
}

.ingredients-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.ingredient-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.ingredient-item:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 12px 25px -5px rgba(18, 73, 98, 0.15);
}

.ing-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 0.95rem;
}

.ing-grams {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--brand-green);
}

.ing-bar-bg {
    width: 100%;
    height: 6px;
    background: var(--input-bg);
    border-radius: 3px;
    overflow: hidden;
}

.ing-bar-fill {
    height: 100%;
    background: var(--brand-green);
    border-radius: 3px;
}

.warnings {
    background: rgba(249, 115, 22, 0.1);
    border-left: 4px solid #F97316;
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-main);
    line-height: 1.5;
}

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

.app-tab {
    display: none;
}
.app-tab.active-tab {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@media (max-width: 768px) {
    body {
        padding: 1rem 0.5rem;
    }
    .logo {
        font-size: 2.5rem;
    }
    .card {
        padding: 1.5rem;
    }
    .options-grid, .age-group, .summary-stats-grid, .ingredients-grid, .dose-grid {
        grid-template-columns: 1fr;
    }
    .stat-box.main-stat .stat-value {
        font-size: 2.8rem;
    }
    header {
        margin-bottom: 1.5rem;
    }
    .btn-primary, .btn-secondary {
        padding: 1rem;
        font-size: 1rem;
    }
    .step h2 {
        font-size: 1.2rem;
    }
    .btn-emergency {
        top: auto;
        bottom: 90px;
        left: 1.5rem;
        width: 60px;
        height: 60px;
        border-radius: 50%;
        padding: 0;
        justify-content: center;
    }
    .emergency-text {
        display: none;
    }
    
    .bottom-bar {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: var(--bg-color);
        border-top: 1px solid var(--border-color);
        justify-content: space-around;
        padding: 0.5rem 1rem;
        z-index: 9998;
        padding-bottom: env(safe-area-inset-bottom, 1rem); /* iPhone safe area */
    }
    .bottom-nav-item {
        display: flex;
        flex-direction: column;
        align-items: center;
        background: transparent;
        border: none;
        color: var(--text-muted);
        cursor: pointer;
        padding: 0.5rem;
        border-radius: 8px;
        transition: all 0.2s;
        width: 60px;
        height: 60px;
        justify-content: center;
    }
    .bottom-nav-item img {
        width: 24px;
        height: 24px;
        opacity: 0.6;
        transition: all 0.2s;
        filter: invert(0);
    }
    [data-theme="dark"] .bottom-nav-item img {
        filter: invert(1);
    }
    .bottom-nav-item.active {
        background: var(--brand-green);
        color: white;
    }
    .bottom-nav-item.active img {
        opacity: 1;
        filter: invert(1); /* Siempre blanco en fondo verde */
    }
    .bottom-nav-item span {
        font-size: 0.7rem;
        margin-top: 4px;
        font-weight: 600;
    }
    #menu-trigger {
        display: none !important;
    }
    /* Añadir padding al dashboard para que la barra no tape el contenido */
    #view-dashboard {
        padding-bottom: 80px;
    }
}

/* Ocultar la barra en PC */
@media (min-width: 769px) {
    .bottom-bar {
        display: none !important;
    }
}