/* ===== VARIABLES Y CONFIGURACIÓN GLOBAL ===== */
:root {
    --primary: #2196F3;
    --primary-dark: #1976D2;
    --success: #4CAF50;
    --success-dark: #388E3C;
    --danger: #F44336;
    --danger-dark: #D32F2F;
    --warning: #FF9800;
    --warning-dark: #F57C00;
    --bg-light: #f5f7fa;
    --bg-white: #ffffff;
    --text-dark: #2c3e50;
    --text-gray: #7f8c8d;
    --text-light: #bdc3c7;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.16);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --font-main: 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
}

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

body {
    font-family: var(--font-main);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    -webkit-tap-highlight-color: transparent;
}

/* ===== LOGIN ===== */
.login-container {
    width: 100%;
    max-width: 420px;
    animation: fadeInUp 0.5s ease;
}

.login-box {
    background: var(--bg-white);
    padding: 48px 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.login-logo {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    font-size: 36px;
}

.login-box h1 {
    color: var(--text-dark);
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.login-box .subtitle {
    color: var(--text-gray);
    font-size: 15px;
    margin-bottom: 32px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-dark);
    font-weight: 600;
    font-size: 14px;
    letter-spacing: 0.3px;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #e8ecf1;
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-family: var(--font-main);
    transition: all 0.3s ease;
    background: var(--bg-light);
    color: var(--text-dark);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--bg-white);
    box-shadow: 0 0 0 4px rgba(33, 150, 243, 0.1);
}

.form-group input::placeholder {
    color: var(--text-light);
}

.btn {
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    font-family: var(--font-main);
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

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

.error-message {
    background: #fff5f5;
    color: #c62828;
    padding: 12px;
    border-radius: var(--radius-sm);
    margin-top: 16px;
    font-size: 14px;
    display: none;
    border: 1px solid #ffcdd2;
}

/* ===== VENTA ===== */
.venta-container {
    width: 100%;
    max-width: 480px;
    min-height: 100vh;
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    animation: fadeInUp 0.5s ease;
}

/* Header */
.header {
    background: linear-gradient(135deg, #667eea, #764ba2);
    padding: 24px 20px;
    color: white;
    position: relative;
    text-align: center;
}

.header h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 4px;
    letter-spacing: -0.5px;
}

.header .cajero-info {
    font-size: 14px;
    opacity: 0.9;
    margin-top: 4px;
}

.header .cajero-info strong {
    font-weight: 700;
}

.btn-logout {
    position: absolute;
    top: 50%;
    left: 16px;
    transform: translateY(-50%);
    background: rgba(255,255,255,0.2);
    color: white;
    border: 1px solid rgba(255,255,255,0.3);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main);
    backdrop-filter: blur(10px);
}

.btn-logout:hover {
    background: rgba(255,255,255,0.3);
}

/* Inventario Status */
.inventario-status {
    display: flex;
    gap: 12px;
    padding: 16px 20px;
    background: var(--bg-light);
    border-bottom: 1px solid #e8ecf1;
}

.stock-info {
    flex: 1;
    background: var(--bg-white);
    padding: 12px;
    border-radius: var(--radius-sm);
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stock-tipo {
    display: block;
    font-size: 12px;
    color: var(--text-gray);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 4px;
}

.stock-cantidad {
    display: block;
    font-size: 28px;
    font-weight: 700;
    color: var(--text-dark);
}

.stock-precio {
    display: block;
    font-size: 13px;
    color: var(--primary);
    font-weight: 600;
    margin-top: 2px;
}

/* Botones de Producto */
.buttons-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    padding: 24px 20px;
}

.btn-producto {
    position: relative;
    padding: 32px 16px;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    overflow: hidden;
    font-family: var(--font-main);
}

.btn-producto::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.2), rgba(255,255,255,0));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.btn-producto:hover::before {
    opacity: 1;
}

.btn-producto:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.btn-producto:active {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-500ml {
    background: linear-gradient(135deg, #43A047, #66BB6A);
    color: white;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

.btn-1lts {
    background: linear-gradient(135deg, #E64A19, #FF7043);
    color: white;
    box-shadow: 0 4px 15px rgba(244, 67, 54, 0.3);
}

.btn-producto .emoji {
    font-size: 36px;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

.btn-producto .tamano {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.btn-producto .precio {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -0.5px;
}

/* Botones de Acción */
.acciones-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    padding: 0 20px 24px;
}

.btn-accion {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-carga {
    background: #FFF3E0;
    color: #E65100;
    border: 2px solid #FFE0B2;
}

.btn-carga:hover {
    background: #FFE0B2;
    transform: translateY(-2px);
}

.btn-cierre {
    background: #FFEBEE;
    color: #B71C1C;
    border: 2px solid #FFCDD2;
}

.btn-cierre:hover {
    background: #FFCDD2;
    transform: translateY(-2px);
}

.btn-accion span:first-child {
    font-size: 20px;
}

/* ===== MODALES ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
    animation: fadeIn 0.3s ease;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--bg-white);
    padding: 32px 28px;
    border-radius: var(--radius-lg);
    max-width: 380px;
    width: 90%;
    box-shadow: var(--shadow-lg);
    animation: scaleIn 0.3s ease;
    text-align: center;
}

.modal-content h2 {
    font-size: 22px;
    color: var(--text-dark);
    margin-bottom: 16px;
    font-weight: 700;
}

.modal-content p {
    font-size: 16px;
    color: var(--text-gray);
    margin-bottom: 24px;
    line-height: 1.5;
}

.modal-content .form-group {
    text-align: left;
}

.modal-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 8px;
}

.btn-confirmar,
.btn-cancelar {
    padding: 14px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-confirmar {
    background: var(--success);
    color: white;
    box-shadow: 0 4px 12px rgba(76, 175, 80, 0.3);
}

.btn-confirmar:hover {
    background: var(--success-dark);
    transform: translateY(-2px);
}

.btn-cancelar {
    background: #eceff1;
    color: var(--text-dark);
}

.btn-cancelar:hover {
    background: #cfd8dc;
    transform: translateY(-2px);
}

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

/* Resumen de cierre */
.resumen-cierre {
    background: var(--bg-light);
    padding: 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    text-align: left;
}

.resumen-cierre p {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid #e8ecf1;
    margin: 0;
    font-size: 14px;
}

.resumen-cierre p:last-child {
    border-bottom: none;
}

.resumen-cierre strong {
    color: var(--text-dark);
    font-weight: 700;
}

/* Mensaje flotante */
.mensaje-flotante {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    padding: 14px 28px;
    border-radius: 30px;
    font-size: 15px;
    font-weight: 700;
    z-index: 2000;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.3s ease;
    letter-spacing: 0.3px;
}

.mensaje-success {
    background: linear-gradient(135deg, #43A047, #66BB6A);
    color: white;
}

.mensaje-error {
    background: linear-gradient(135deg, #E53935, #EF5350);
    color: white;
}

/* ===== ANIMACIONES ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

/* ===== RESPONSIVE ===== */
@media (max-width: 480px) {
    body {
        padding: 0;
        align-items: flex-start;
    }
    
    .login-container {
        padding: 20px;
        margin-top: 40px;
    }
    
    .login-box {
        padding: 36px 24px;
    }
    
    .venta-container {
        min-height: 100vh;
        border-radius: 0;
        box-shadow: none;
    }
    
    .buttons-container {
        padding: 20px 16px;
        gap: 12px;
    }
    
    .btn-producto {
        padding: 28px 12px;
    }
    
    .btn-producto .emoji {
        font-size: 32px;
    }
    
    .btn-producto .precio {
        font-size: 22px;
    }
    
    .acciones-container {
        padding: 0 16px 20px;
    }
    
    .modal-content {
        padding: 24px 20px;
    }
}

/* ===== DARK MODE (Opcional) ===== */
@media (prefers-color-scheme: dark) {
    /* Puedes agregar estilos para modo oscuro aquí si lo deseas */
}