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

body {
    background: url('../../bg.jpg') no-repeat center center fixed;
    background-size: cover;
    color: #ffffff;
    height: 100vh;
    overflow: hidden;
    position: relative;
}


body::before {
    content: "";
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.6); /* Độ tối 60% */
    z-index: -1;
}

.navbar {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 60px;
    background-color: rgba(11, 14, 17, 0.95);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    z-index: 100;
    border-bottom: 1px solid #232527;
}

.navbar-center {
    display: flex;
    gap: 20px;
}

.navbar-center a {
    text-decoration: none;
    color: #b8b8b8;
    font-size: 15px;
    font-weight: 500;
}

.navbar-center a:hover { color: #fff; }

.search-box {
    display: flex;
    align-items: center;
    background: #232527;
    border: 1px solid #4f555b;
    border-radius: 8px;
    padding: 5px 10px;
}

.search-box input {
    background: none; border: none; color: #fff; padding-left: 10px; outline: none;
}

.btn-signup {
    background: #007fff;
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 8px 18px;
    font-weight: 700;
    cursor: pointer;
}

.background-content {
    position: absolute;
    top: 60px; left: 0; width: 100%; height: 100%;
    z-index: -1;
    overflow: hidden;
    opacity: 0.4; 
}

.tiles-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
    padding: 50px;
    perspective: 1000px;
}

.tile {
    width: 150px; height: 150px;
    background-size: cover;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.1);
}

.tilt-right-low { transform: rotateX(10deg) rotateY(15deg) rotateZ(-5deg); }
.tilt-left-low { transform: rotateX(10deg) rotateY(-15deg) rotateZ(5deg); }

.login-modal {
    position: fixed;
    top: 55%; left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;
}

.login-form {
    background-color: #393b3d;
    border-radius: 12px;
    padding: 35px;
    width: 400px;
    max-width: 95vw;
    box-shadow: 0 8px 25px rgba(0,0,0,0.5);
    text-align: center;
}

.login-form h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 25px;
}

/* INPUTS */
.input-group {
    width: 100%;
    margin-bottom: 15px;
}

.input-group input {
    width: 100%;
    background-color: #232527;
    border: 1px solid #4f555b;
    border-radius: 8px;
    padding: 12px 15px;
    color: #fff;
    font-size: 16px;
    outline: none;
}

.input-group input:focus { border-color: #fff; }

/* BUTTONS */
.btn-login-main {
    width: 100%;
    background: transparent;
    color: #fff;
    border: 1px solid #b8b8b8;
    border-radius: 8px;
    padding: 12px;
    font-weight: 700;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
    transition: 0.2s;
}

.btn-login-main:hover { background: rgba(255,255,255,0.1); border-color: #fff; }

.btn-alt-login {
    width: 100%;
    background: #4f555b;
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 10px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    margin-top: 10px;
}

.or-separator {
    color: #b8b8b8;
    font-size: 12px;
    text-transform: uppercase;
    margin: 15px 0;
    display: flex; align-items: center;
}
.or-separator::before, .or-separator::after {
    content: ""; flex: 1; height: 1px; background: #4f555b; margin: 0 10px;
}

.signup-prompt { font-size: 14px; color: #b8b8b8; margin-top: 20px; }
.signup-prompt a { color: #007fff; text-decoration: none; font-weight: 700; }

/* ANIMATION QUAY TRÒN (LOADING) */
@keyframes spin { 100% { transform: rotate(360deg); } }

/* RESPONSIVE */
@media (max-height: 700px) {
    .login-modal { top: 60%; }
    .login-form { padding: 25px; }
}