/* ========================================
   VARIABLES Y CONFIGURACIÓN GLOBAL
   ======================================== */
   :root {
    /* Colores Windows 11 mejorados */
    --win11-blue: #0078D4;
    --win11-blue-dark: #006CBE;
    --win11-blue-light: #4C9EE8;
    --win11-light-blue: #E6F3FF;
    --win11-dark: #202020;
    --win11-gray: #F3F3F3;
    --win11-border: #E0E0E0;
    --win11-white: #FFFFFF;
    --win11-shadow: rgba(0, 0, 0, 0.1);
    
    /* Colores de éxito */
    --success-green: #107C10;
    --success-green-dark: #0B6A0B;
    --success-light: #DFF6DD;
    
    /* Sombras mejoradas */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.15);
    
    /* Transiciones */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Border radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
}

/* ========================================
   RESET Y BASE
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e8ecf1 100%);
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    min-height: 100vh;
    color: var(--win11-dark);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    padding: 1rem;
}

/* ========================================
   CONTENEDOR PRINCIPAL
   ======================================== */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
}

/* ========================================
   TARJETA PRINCIPAL
   ======================================== */
.card {
    background: var(--win11-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    border: 1px solid rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(10px);
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   HEADER
   ======================================== */
.card-header {
    background: linear-gradient(135deg, var(--win11-blue) 0%, var(--win11-blue-dark) 100%);
    padding: 2rem 1.5rem;
    color: var(--win11-white);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.card-header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 200px;
    height: 200px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: float 6s ease-in-out infinite;
}

.card-header::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -5%;
    width: 150px;
    height: 150px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
    animation: float 8s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(10deg); }
}

.card-header h4 {
    margin: 0;
    font-weight: 600;
    font-size: 1.5rem;
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ========================================
   CUERPO DE LA TARJETA
   ======================================== */
.card-body {
    padding: 2rem 1.5rem;
}

/* ========================================
   FORMULARIOS
   ======================================== */
.mb-4 {
    margin-bottom: 1.5rem !important;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--win11-dark);
    font-size: 0.95rem;
    transition: color var(--transition-fast);
}

.form-control, 
.form-select {
    width: 100%;
    padding: 1rem 1.25rem;
    border: 2px solid var(--win11-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background-color: var(--win11-white);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.form-control:hover, 
.form-select:hover {
    border-color: var(--win11-blue-light);
    box-shadow: 0 2px 8px rgba(0, 120, 212, 0.1);
}

.form-control:focus, 
.form-select:focus {
    outline: none;
    border-color: var(--win11-blue);
    box-shadow: 0 0 0 4px rgba(0, 120, 212, 0.15), var(--shadow-md);
    transform: translateY(-2px);
}

.form-control::placeholder {
    color: #999;
    opacity: 0.7;
}

/* Select personalizado */
.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%230078D4' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1.25rem center;
    padding-right: 3rem;
    cursor: pointer;
}

/* ========================================
   BOTONES
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 1.05rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--win11-blue) 0%, var(--win11-blue-dark) 100%);
    color: var(--win11-white);
    width: 100%;
    padding: 1.25rem;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 120, 212, 0.4);
    background: linear-gradient(135deg, var(--win11-blue-light) 0%, var(--win11-blue) 100%);
}

.btn-primary:active {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 120, 212, 0.3);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* ========================================
   RESULTADOS
   ======================================== */
#resultado {
    animation: fadeInScale 0.5s ease-out;
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.alert {
    padding: 2rem;
    border-radius: var(--radius-lg);
    border: none;
    margin-top: 2rem;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.alert::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.5), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.alert-success {
    background: linear-gradient(135deg, var(--success-green) 0%, var(--success-green-dark) 100%);
    color: var(--win11-white);
}

.alert h5 {
    font-weight: 600;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.display-4 {
    font-size: 3.5rem;
    font-weight: 700;
    margin: 1rem 0;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    animation: countUp 0.8s ease-out;
}

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

/* ========================================
   UTILIDADES
   ======================================== */
.fw-bold {
    font-weight: 700 !important;
}

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

.mb-0 {
    margin-bottom: 0 !important;
}

.mb-2 {
    margin-bottom: 0.5rem !important;
}

.d-none {
    display: none !important;
}

.w-100 {
    width: 100% !important;
}

.shadow-lg {
    box-shadow: var(--shadow-lg) !important;
}

.border-0 {
    border: none !important;
}

/* ========================================
   RESPONSIVE DESIGN - MOBILE FIRST
   ======================================== */

/* Tablets y dispositivos medianos */
@media (min-width: 768px) {
    body {
        padding: 2rem;
    }
    
    .container {
        padding: 1.5rem;
    }
    
    .card-header {
        padding: 2.5rem 2rem;
    }
    
    .card-header h4 {
        font-size: 1.75rem;
    }
    
    .card-body {
        padding: 2.5rem 2rem;
    }
    
    .form-control, 
    .form-select {
        padding: 1.125rem 1.5rem;
    }
}

/* Desktop y dispositivos grandes */
@media (min-width: 1024px) {
    body {
        padding: 3rem;
        background: linear-gradient(135deg, #f5f7fa 0%, #e8ecf1 50%, #d5dbe3 100%);
    }
    
    .container {
        max-width: 900px;
        padding: 2rem;
    }
    
    .card {
        border-radius: var(--radius-xl);
    }
    
    .card-header {
        padding: 3rem 2.5rem;
    }
    
    .card-header h4 {
        font-size: 2rem;
    }
    
    .card-body {
        padding: 3rem 2.5rem;
    }
    
    .btn {
        padding: 1.25rem 2.5rem;
    }
    
    .alert {
        padding: 2.5rem;
    }
    
    .display-4 {
        font-size: 4.5rem;
    }
}

/* Pantallas muy grandes */
@media (min-width: 1440px) {
    body {
        padding: 4rem;
    }
    
    .container {
        max-width: 1000px;
    }
    
    .display-4 {
        font-size: 5rem;
    }
}

/* ========================================
   MODO OSCURO (Opcional - Auto-detect)
   ======================================== */
@media (prefers-color-scheme: dark) {
    :root {
        --win11-dark: #FFFFFF;
        --win11-gray: #1a1a1a;
        --win11-white: #2d2d2d;
        --win11-border: #404040;
    }
    
    body {
        background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
        color: var(--win11-white);
    }
    
    .card {
        background: var(--win11-white);
        border-color: var(--win11-border);
    }
    
    .form-label {
        color: var(--win11-white);
    }
}

/* ========================================
   ACCESIBILIDAD
   ======================================== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus visible para navegación por teclado */
*:focus-visible {
    outline: 3px solid var(--win11-blue);
    outline-offset: 2px;
}

/* ========================================
   OPTIMIZACIONES PARA iOS Y ANDROID
   ======================================== */

/* Evitar zoom en inputs en iOS */
@media screen and (max-width: 1024px) {
    input, select, textarea {
        font-size: 16px !important;
    }
}

/* Touch targets más grandes en móvil */
@media (max-width: 768px) {
    .form-control, 
    .form-select,
    .btn {
        min-height: 48px;
        touch-action: manipulation;
    }
    
    .btn {
        padding: 1rem;
        font-size: 1.1rem;
    }
}

/* Mejorar rendimiento en móviles */
.card, 
.btn, 
.form-control, 
.form-select {
    will-change: transform, box-shadow;
}

/* ========================================
   EFECTOS ADICIONALES
   ======================================== */

/* Loading state */
.btn.loading {
    position: relative;
    color: transparent;
}

.btn.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Error state */
.form-control.error,
.form-select.error {
    border-color: #d32f2f;
    box-shadow: 0 0 0 4px rgba(211, 47, 47, 0.15);
}

/* Success state */
.form-control.success,
.form-select.success {
    border-color: var(--success-green);
    box-shadow: 0 0 0 4px rgba(16, 124, 16, 0.15);
}