:root {
    --radius: 12px;
    --spacing: 2.5rem;
    --brand: #007bff;
    --brand-dark: #0056b3;
}

/* Base */
html,
body {
    height: 100%;
}

body {
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    background:
        linear-gradient(rgba(0, 0, 0, .5), rgba(0, 0, 0, .5)),
        url('../images/background.png') center / cover no-repeat #0b0b0b;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100dvh;
    /* melhor em mobile que 100vh */
    margin: 0;
    padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

/* Card de login */
.login-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    width: min(420px, 92vw);
    /* fluido em telas pequenas */
    padding: var(--spacing);
    border-radius: var(--radius);
    box-shadow: 0 8px 32px rgba(0, 0, 0, .25);
}

.logo-container {
    text-align: center;
    margin-bottom: 1.25rem;
}

.logo {
    width: min(70%, 320px);
    /* reduz em telas pequenas */
    height: auto;
    display: block;
    margin: -.75rem auto 0;
    /* leve subida */
}

/* Form */
form {
    margin: 0;
}

input,
button {
    font-size: clamp(.95rem, 2.5vw, 1rem);
}

input {
    display: block;
    width: 100%;
    margin-bottom: 1rem;
    padding: .9rem .95rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-sizing: border-box;
    background: #fff;
}

input:focus {
    outline: none;
    border-color: var(--brand);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, .25);
}

button {
    width: 100%;
    padding: .9rem 1rem;
    background: var(--brand);
    color: #fff;
    border: 0;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 700;
    transition: filter .2s ease;
    touch-action: manipulation;
}

button:hover {
    filter: brightness(.95);
}

button:active {
    filter: brightness(.9);
}

.mensagem {
    color: #d93025;
    margin: .25rem 0 1rem;
    text-align: center;
    font-size: .95rem;
    min-height: 1.25rem;
    /* evita pulo de layout quando aparecer texto */
}

.mensagem.sucesso {
    color: #28a745;
}

/* Ajustes para telas muito pequenas */
@media (max-width: 480px) {
    :root {
        --spacing: 1.25rem;
    }

    .login-container {
        box-shadow: 0 6px 20px rgba(0, 0, 0, .2);
    }

    .logo {
        width: min(78%, 280px);
        margin-top: -.5rem;
    }

    input,
    button {
        border-radius: 10px;
    }
}

/* Telas extra pequenas (ex.: 320px) */
@media (max-width: 360px) {
    .logo {
        width: 82%;
    }

    input,
    button {
        padding: .8rem .85rem;
    }
}

/* Acessibilidade: reduzir animações se preferido */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
    }
}