/* ===== RESET ===== */
*{
    box-sizing:border-box;
    margin:0;
    padding:0;
    font-family: 'Segoe UI', Tahoma, sans-serif;
}

/* ===== NỀN TRANG GAMING ===== */
body{
    min-height:100vh;
    display:flex;
    align-items:center;
    justify-content:center;
    background: radial-gradient(circle at top, #1a2a6c, #0b0b15 60%, #000 100%);
    position: relative;
    overflow:hidden;
    color:#fff;
}

/* glow neon nền */
body::before{
    content:"";
    position:absolute;
    width:560px;
    height:560px;
    background:rgba(0,255,255,.18);
    filter:blur(120px);
    top:-160px;
    left:-160px;
    pointer-events:none;
}

body::after{
    content:"";
    position:absolute;
    width:560px;
    height:560px;
    background:rgba(255,0,200,.14);
    filter:blur(120px);
    bottom:-160px;
    right:-160px;
    pointer-events:none;
}

/* ===== KHUNG FORM GLASS ===== */
.auth-box{
    width:100%;
    max-width:420px;
    background: rgba(15, 15, 25, 0.78);
    padding:32px 30px;
    border-radius:18px;

    border:1px solid rgba(255,255,255,0.08);
    box-shadow: 0 12px 40px rgba(0,0,0,.55);
    backdrop-filter: blur(10px);

    position:relative;
    z-index:2;
    animation: fadeUp .45s ease;
}

/* neon line top */
.auth-box::before{
    content:"";
    position:absolute;
    left:16px;
    right:16px;
    top:-1px;
    height:2px;
    background:linear-gradient(90deg, transparent, #00ffff, #ff00cc, transparent);
    opacity:.9;
}

/* ===== HIỆU ỨNG VÀO ===== */
@keyframes fadeUp{
    from{ opacity:0; transform:translateY(18px); }
    to{ opacity:1; transform:translateY(0); }
}

/* ===== TIÊU ĐỀ ===== */
.auth-box h2{
    text-align:center;
    margin-bottom:18px;
    font-size:20px;
    letter-spacing:.6px;
    text-transform:uppercase;
    color:#fff;
}

/* ===== FORM ===== */
.auth-box form{
    display:flex;
    flex-direction:column;
    gap:12px;
}

/* ===== INPUT GAMING ===== */
.auth-box input{
    width:100%;
    padding:12px 14px;
    border-radius:14px;
    border:1px solid rgba(255,255,255,0.10);
    background: rgba(255,255,255,0.04);
    color:#fff;
    font-size:14px;
    transition:.22s;
}

.auth-box input::placeholder{
    color: rgba(255,255,255,0.55);
}

.auth-box input:focus{
    outline:none;
    border-color: rgba(0,255,255,0.55);
    box-shadow: 0 0 0 4px rgba(0,255,255,0.12);
}

/* ===== BUTTON NEON ===== */
.auth-box button{
    padding:12px 14px;
    border:none;
    border-radius:14px;

    background: linear-gradient(135deg, rgba(0,255,255,.18), rgba(255,0,204,.16));
    color:#fff;
    font-weight:800;
    cursor:pointer;
    letter-spacing:.3px;
    transition:.25s;

    border:1px solid rgba(255,255,255,0.08);
    box-shadow: 0 10px 22px rgba(0,0,0,.35);
}

.auth-box button:hover{
    transform:translateY(-2px);
    border-color: rgba(0,255,255,.35);
    box-shadow: 0 16px 30px rgba(0,0,0,.55);
}

/* ===== THÔNG BÁO ===== */
.auth-message{
    margin-top:14px;
    font-size:14px;
    text-align:center;
    color: rgba(255,255,255,0.88);
    opacity:.9;
}

/* ===== LINK PHỤ ===== */
.auth-link{
    display:block;
    margin-top:12px;
    text-align:center;
    font-size:13px;
    text-decoration:none;
    font-weight:700;
    color:#00ffff;
    opacity:.9;
    transition:.2s;
}

.auth-link:hover{
    opacity:1;
    text-decoration: underline;
}

/* ===== MOBILE ===== */
@media(max-width:480px){
    .auth-box{
        margin:20px;
        padding:26px 18px;
        border-radius:16px;
    }

    .auth-box h2{
        font-size:18px;
    }
}