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

/* ===== VARIABLES ===== */
:root {
    --primary: #2563eb;
    --secondary: #7c3aed;
    --accent: #06b6d4;
    --glass: rgba(255,255,255,0.06);
    --border: rgba(255,255,255,0.15);
}

/* ===== BODY ===== */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;

    background:
        radial-gradient(circle at 20% 20%, rgba(37,99,235,0.25), transparent 40%),
        radial-gradient(circle at 80% 80%, rgba(124,58,237,0.25), transparent 40%),
        linear-gradient(135deg, #0f172a, #1e293b, #312e81);

    min-height: 100vh;

    display: flex;
    justify-content: center;
    align-items: center;
}

/* ===== CONTENEDOR PRINCIPAL ===== */
.auth-container {
    display: grid;
    grid-template-columns: 1fr 1fr;

    width: 900px;
    max-width: 95%;

    border-radius: 20px;
    overflow: hidden;

    backdrop-filter: blur(20px);
    background: var(--glass);
    border: 1px solid var(--border);

    box-shadow: 0 25px 60px rgba(0,0,0,0.4);
}

/* ===== LADO IZQUIERDO ===== */
.brand-side {
    padding: 60px 40px;

    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;

    background:
        linear-gradient(135deg, rgba(37,99,235,0.3), rgba(124,58,237,0.3));
}

.brand-side img {
    width: 220px;
    margin-bottom: 30px;
    filter: drop-shadow(0 15px 25px rgba(0,0,0,0.5));
    transition: 0.4s ease;
}

.brand-side img:hover {
    transform: scale(1.08);
    filter: drop-shadow(0 0 25px rgba(6,182,212,0.8));
}

.brand-side h2 {
    color: white;
    font-size: 28px;
    margin-bottom: 15px;
    text-align: center;
}

.brand-side p {
    color: rgba(255,255,255,0.8);
    text-align: center;
    font-size: 15px;
    max-width: 280px;
}

/* ===== LADO DERECHO ===== */
.login-side {
    padding: 60px 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.login-side h1 {
    color: white;
    margin-bottom: 30px;
    font-size: 26px;
}

/* ===== FORM ===== */
form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

form label {
    color: rgba(255,255,255,0.85);
    font-size: 14px;
}

form input {
    padding: 12px 14px;
    border-radius: 10px;
    border: 1px solid rgba(255,255,255,0.15);
    background: rgba(255,255,255,0.08);
    color: white;
    outline: none;
    transition: 0.3s;
}

form input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 12px rgba(6,182,212,0.5);
}

/* ===== CHECKBOX ===== */
.checkbox-group {
    display: flex;
    gap: 8px;
    color: white;
    font-size: 14px;
}

/* ===== BOTÓN ===== */
form button {
    margin-top: 10px;
    padding: 12px;
    font-size: 16px;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: 0.3s;
}

form button:hover {
    transform: translateY(-3px);
    box-shadow:
        0 15px 35px rgba(0,0,0,0.4),
        0 0 25px rgba(37,99,235,0.6);
}

/* ===== ERROR ===== */
.error-msg {
    background: rgba(255,0,0,0.15);
    border: 1px solid rgba(255,0,0,0.4);
    color: #ff6b6b;
    padding: 10px;
    border-radius: 8px;
    text-align: center;
}

/* ============================= */
/* ===== RESPONSIVE SYSTEM ===== */
/* ============================= */

/* ===== TABLET ===== */
@media (max-width: 992px) {
    .auth-container {
        width: 95%;
    }
}

/* ===== TABLET PEQUEÑA / MÓVIL GRANDE ===== */
@media (max-width: 768px) {

    body {
        align-items: flex-start;
        padding: 50px 15px;
    }

    .auth-container {
        grid-template-columns: 1fr;
        border-radius: 22px;
    }

    /* Branding más compacto pero visible */
    .brand-side {
        padding: 30px 20px 15px 20px;
    }

    .brand-side img {
        width: 140px;
        margin-bottom: 10px;
    }

    .brand-side h2 {
        font-size: 20px;
        margin-bottom: 6px;
    }

    .brand-side p {
        font-size: 13px;
        max-width: 100%;
    }

    .login-side {
        padding: 30px 20px 35px 20px;
    }

    .login-side h1 {
        font-size: 22px;
        margin-bottom: 20px;
        text-align: center;
    }

    form {
        gap: 14px;
    }

    form input {
        padding: 11px 12px;
        font-size: 14px;
    }

    form button {
        padding: 13px;
        font-size: 15px;
    }
}

/* ===== MÓVIL PEQUEÑO ===== */
@media (max-width: 480px) {

    body {
        padding: 40px 12px;
    }

    .auth-container {
        border-radius: 20px;
    }

    /* Logo centrado arriba tipo app */
    .brand-side {
        padding: 25px 15px 10px 15px;
    }

    .brand-side img {
        width: 110px;
        margin-bottom: 8px;
    }

    .brand-side h2 {
        font-size: 18px;
    }

    .brand-side p {
        font-size: 12px;
    }

    .login-side {
        padding: 25px 18px 30px 18px;
    }

    .login-side h1 {
        font-size: 20px;
    }

    form input {
        padding: 10px;
        font-size: 14px;
    }

    form button {
        padding: 12px;
        font-size: 14px;
    }
}