Y:root {
    --radius: 20px;
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.3);
}

/* === MODO OSCURO (BRUTAL) === */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0a0a0a;
        --page-gradient: linear-gradient(135deg, #000000 0%, #1a0000 100%);
        --glass: rgba(15, 15, 15, 0.85);
        --border-glow: #ff0000;
        --text-primary: #ffffff;
        --text-muted: #ff6666;
        --input-bg: rgba(255, 255, 255, 0.1);
        --input-text: #ffffff;
        --btn-from: #ff1a1a;
        --btn-to: #cc0000;
        --led: #ff0000;
        --led-glow: #ff3333;
    }
}

/* === MODO CLARO (ÉPICO) === */
@media (prefers-color-scheme: light) {
    :root {
        --bg: #f0f7ff;
        --page-gradient: linear-gradient(135deg, #e0f2fe 0%, #f0fdf4 100%);
        --glass: rgba(255, 255, 255, 0.92);
        --border-glow: #ff0000ff;
        --text-primary: #000000;
        --text-muted: #640000ff;
        --input-bg: rgba(0, 0, 0, 0.06);
        --input-text: #000000;
        --btn-from: #cc0000ff;
        --btn-to: #cc0000ff;
        --led: #cc0000ff;
        --led-glow: #cc0000ff;
    }
}

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

body {
    background: var(--page-gradient);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Nunito', sans-serif;
    padding: 20px;
    overflow-x: hidden;
    transition: var(--transition);
    color: var(--text-primary);
}

/* === FONDO CON GRADIENTE SUAVE === */
.page-bg {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: var(--page-gradient);
    z-index: -2;
}

/* === CONTENEDOR FLOTANTE === */
.login-wrapper {
    position: relative;
    width: 100%;
    max-width: 460px;
    margin: 0 auto;
    animation: float 6s infinite ease-in-out;
    z-index: 10;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

/* === GLASS CONTAINER CON BORDE NEÓN === */
.login-container {
    position: relative;
    background: var(--glass);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-radius: var(--radius);
    padding: 50px 38px;
    border: 1.5px solid var(--border-glow);
    box-shadow: 
        var(--shadow-lg),
        0 0 40px var(--border-glow),
        0 0 80px var(--border-glow) inset;
    overflow: hidden;
    animation: fadeIn 0.9s ease-out forwards;
    opacity: 0;
    z-index: 2;
    color: var(--text-primary);
}

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

/* === LED PULSANTE DEBAJO === */
.led-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 92vw;
    max-width: 540px;
    height: 92vw;
    max-height: 540px;
    border-radius: 50%;
    background: radial-gradient(
        circle at center,
        var(--led) 0%,
        var(--led-glow) 25%,
        transparent 65%
    );
    filter: blur(28px);
    opacity: 0.75;
    transform: translate(-50%, -50%);
    animation: pulseLED 3s ease-in-out infinite;
    z-index: 1;
    pointer-events: none;
}

@keyframes pulseLED {
    0%, 100% { 
        opacity: 0.65; 
        filter: blur(25px); 
        transform: translate(-50%, -50%) scale(1);
    }
    50% { 
        opacity: 0.95; 
        filter: blur(35px); 
        transform: translate(-50%, -50%) scale(1.08);
    }
}

/* === LOGO === */
.logo {
    width: 125px;
    height: auto;
    display: block;
    margin: 0 auto 30px;
    filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.35));
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.1);
}

/* === TÍTULO CON GRADIENTE === */
.welcome-text {
    text-align: center;
    font-size: 1.9rem;
    font-weight: 900;
    margin-bottom: 34px;
    background: linear-gradient(90deg, 
        var(--border-glow), 
        #ff1e1eff, 
        var(--border-glow)
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.6px;
}

/* === INPUTS === */
.form-group {
    position: relative;
    margin-bottom: 28px;
}

.form-control {
    width: 100%;
    padding: 18px 20px 10px;
    font-size: 1rem;
    background: var(--input-bg);
    border: 2px solid transparent;
    border-radius: 14px;
    color: var(--input-text);
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--border-glow);
    box-shadow: 
        0 0 0 4px rgba(0, 255, 0, 0.2),
        0 0 20px var(--border-glow);
    transform: translateY(-2px);
}

.form-label {
    position: absolute;
    left: 20px;
    top: 18px;
    font-size: 1rem;
    color: var(--text-muted);
    pointer-events: none;
    transition: var(--transition);
    font-weight: 600;
}

.form-control:focus ~ .form-label,
.form-control:not(:placeholder-shown) ~ .form-label {
    top: 8px;
    font-size: 0.8rem;
    color: var(--border-glow);
    font-weight: 700;
}

/* === TOGGLE === */
.toggle-password {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.1rem;
    cursor: pointer;
    transition: var(--transition);
}

.toggle-password:hover {
    color: var(--border-glow);
    transform: translateY(-50%) scale(1.2);
}

/* === CHECKBOX === */
.custom-control {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 20px 0;
    font-size: 0.95rem;
    color: var(--text-primary);
}

.custom-control-input {
    width: 19px;
    height: 19px;
    accent-color: var(--border-glow);
    cursor: pointer;
    border-radius: 6px;
}

.custom-control-label {
    color: var(--text-primary);
    cursor: pointer;
}

/* === BOTÓN PREMIUM === */
.btn-login {
    width: 100%;
    padding: 17px;
    background: linear-gradient(135deg, var(--btn-from), var(--btn-to));
    color: white;
    border: none;
    border-radius: 14px;
    font-weight: 800;
    font-size: 1.12rem;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
    transition: var(--transition);
}

.btn-login::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
    transition: left 0.7s ease;
}

.btn-login:hover::before { left: 100%; }
.btn-login:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
}

.btn-login:active {
    transform: translateY(-1px);
}

/* === ENLACE === */
.forgot-password {
    display: block;
    text-align: center;
    margin-top: 26px;
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

.forgot-password:hover {
    color: var(--border-glow);
    text-decoration: underline;
}

/* === ALERTA === */
.alert-danger {
    background: rgba(255, 0, 0, 0.12);
    border: 1px solid var(--border-glow);
    color: var(--text-primary);
    padding: 15px 18px;
    border-radius: 12px;
    margin-bottom: 24px;
    font-size: 0.9rem;
    text-align: center;
    backdrop-filter: blur(6px);
}

/* === MENSAJES DE ERROR === */
.error-message {
    color: var(--border-glow);
    font-size: 0.85rem;
    margin-top: 5px;
    font-weight: 600;
    min-height: 20px;
    transition: all 0.3s ease;
}

/* === RESPONSIVE === */
@media (max-width: 480px) {
    .login-container {
        padding: 38px 26px;
        border-radius: 18px;
    }
    .welcome-text { font-size: 1.65rem; }
    .logo { width: 105px; }
    .led-ring { 
        width: 82vw; 
        height: 82vw; 
        max-width: 420px; 
        max-height: 420px; 
    }
}