* { box-sizing: border-box; }

html, body {
    margin: 0;
    min-height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
    background: #f4f4f4;
    color: #171717;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 22px;
}

.auth-card {
    width: 100%;
    max-width: 430px;
    background: white;
    border: 1px solid #e5e5e5;
    border-radius: 18px;
    padding: 28px;
    box-shadow: 0 12px 36px rgba(0,0,0,.06);
}

.brand {
    font-size: 18px;
    font-weight: 700;
}

.subtitle {
    margin-top: 3px;
    color: #888;
    font-size: 12px;
}

h1 {
    margin: 28px 0 20px;
    font-size: 25px;
}

.intro {
    background: #f6f6f6;
    border-radius: 12px;
    padding: 12px;
    line-height: 1.6;
    font-size: 13px;
    margin-bottom: 18px;
}

label {
    display: block;
    margin: 15px 0 6px;
    font-size: 13px;
    font-weight: 600;
}

input {
    width: 100%;
    height: 44px;
    border: 1px solid #ccc;
    border-radius: 10px;
    padding: 0 11px;
    font: inherit;
    outline: none;
}

input:focus {
    border-color: #777;
}

button {
    width: 100%;
    height: 45px;
    margin-top: 22px;
    border: 0;
    border-radius: 10px;
    background: #111;
    color: white;
    font: inherit;
    cursor: pointer;
}

.error {
    background: #fff0f0;
    color: #9e1b1b;
    border-radius: 10px;
    padding: 10px 12px;
    line-height: 1.5;
    font-size: 13px;
    margin-bottom: 10px;
}

.note {
    margin-top: 18px;
    color: #777;
    font-size: 12px;
    line-height: 1.6;
}

@media (max-width: 600px) {
    body {
        align-items: flex-start;
        padding: max(24px, env(safe-area-inset-top)) 16px max(24px, env(safe-area-inset-bottom));
    }
    .auth-card {
        margin-top: 8vh;
        padding: 22px 18px;
        border-radius: 16px;
    }
    input { font-size: 16px; }
}