:root {
    --bg-dark: #0b0f1a;
    --bg-light: #f4f6fb;
    --card-dark: rgba(0,0,0,0.7);
    --card-light: #ffffff;
    --text-dark: #ffffff;
    --text-light: #111111;
}

body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background: var(--bg-dark);
    color: var(--text-dark);
    transition: 0.3s;
}

body.light {
    background: var(--bg-light);
    color: var(--text-light);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
}

/* 📦 CONTENEDORES */
.contenedor, .total-general {
    position: relative;
    margin: 15px auto;
    padding: 18px;
    width: 92%;
    max-width: 420px;
    border-radius: 16px;
    background: var(--card-dark);
    text-align: center;
}

body.light .contenedor,
body.light .total-general {
    background: var(--card-light);
}

/* 🌈 BORDE CAMALEÓN NEÓN */
.camaleon::before {
    content: "";
    position: absolute;
    inset: -2px;
    border-radius: 18px;
    background: linear-gradient(
        45deg,
        #00f, #0ff, #0f0, #ff0, #f00, #f0f
    );
    animation: camaleon 4s linear infinite;
    z-index: -1;
}

@keyframes camaleon {
    0% { filter: hue-rotate(0deg); }
    100% { filter: hue-rotate(360deg); }
}

/* 🔥 BOTONES NEÓN */
.neon {
    padding: 14px;
    font-size: 17px;
    border: none;
    border-radius: 12px;
    color: #fff;
    background: #111;
    box-shadow: 0 0 10px #0080ff, 0 0 25px #0080ff;
    cursor: pointer;
    transition: 0.2s;
}

.neon:hover {
    transform: scale(1.05);
    box-shadow: 0 0 20px #0080ff, 0 0 45px #0080ff;
}

.neon.yape {
    box-shadow: 0 0 10px #00ff88, 0 0 25px #00ff88;
}

.neon.yape:hover {
    box-shadow: 0 0 20px #00ff88, 0 0 45px #00ff88;
}

.neon.undo {
    margin: 10px auto;
    display: block;
    background: #300;
    box-shadow: 0 0 12px red, 0 0 30px red;
}

.neon.small {
    padding: 8px 12px;
    font-size: 14px;
}

/* 📱 BOTONES RESPONSIVE */
.botones {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

/* 📋 HISTORIAL */
.historial {
    max-height: 260px;
    overflow-y: auto;
}

.historial ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.historial li {
    padding: 8px;
    margin-bottom: 6px;
    font-size: 14px;
    border-bottom: 1px solid rgba(255,255,255,0.2);
}

/* 📱 ADAPTACIÓN EXTRA MÓVIL */
@media (max-width: 480px) {
    h1 { font-size: 18px; }
    .neon { font-size: 16px; padding: 14px; }
}