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

/* BODY BACKGROUND + EFFECT */
body {
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #2196f3, #1e88e5);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

    /* Floating background orbs */
    body::before,
    body::after {
        content: "";
        position: absolute;
        border-radius: 50%;
        filter: blur(50px);
        opacity: 0.6;
    }

    body::before {
        width: 400px;
        height: 400px;
        background: radial-gradient(circle, rgba(255, 0, 0, 0.15), transparent 70%);
        top: -100px;
        left: -100px;
        animation: float 6s ease-in-out infinite;
    }

    body::after {
        width: 300px;
        height: 300px;
        background: radial-gradient(circle, rgba(0, 255, 0, 0.15), transparent 70%);
        bottom: -80px;
        right: -80px;
        animation: float 8s ease-in-out infinite reverse;
    }

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(30px);
    }
}

/* MAIN CONTAINER */
.container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 50px 40px;
    width: 100%;
    max-width: 420px;
    z-index: 10;
    animation: slideUp 0.6s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* LOGO SECTION */
.logo-section {
    text-align: center;
    margin-bottom: 30px;
}

    .logo-section img {
        width: 90px;
        height: auto;
        margin-bottom: 10px;
        filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
    }

.company-name {
    font-size: 24px;
    font-weight: 700;
    display: flex;
    justify-content: center;
    gap: 3px;
}

.s-text {
    color: red;
}

.t-text {
    color: green;
}

.u-text {
    color: blue;
}

.company-tagline {
    font-size: 12px;
    display: flex;
    justify-content: center;
    color: #555;
    font-style: italic;
}

/* TITLE */
h1 {
    text-align: center;
    color: #1a1a2e;
    margin-bottom: 30px;
    font-size: 26px;
    font-weight: 600;
}

/* INPUT FIELDS */
.form-group {
    margin-bottom: 20px;
    position: relative;
}

label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 500;
    font-size: 14px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 15px;
    font-size: 18px;
    color: #0f3460;
    pointer-events: none;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 12px 15px 12px 45px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.3s ease;
    background: #f9f9f9;
}

input:focus {
    outline: none;
    border-color: #0f3460;
    background: #fff;
    box-shadow: 0 0 0 3px rgba(15, 52, 96, 0.1);
}

/* BUTTON */
.btn-login {
    width: 100%;
    padding: 12px;
    background: linear-gradient(90deg, #ff0000, #00ff00, #0000ff);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
    position: relative;
    overflow: hidden;
}

    .btn-login::before {
        content: "";
        position: absolute;
        top: 0;
        left: -100%;
        width: 100%;
        height: 100%;
        background: rgba(255, 255, 255, 0.2);
        transition: left 0.3s ease;
    }

    .btn-login:hover::before {
        left: 100%;
    }

    .btn-login:hover {
        transform: translateY(-2px);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    }

/* ERROR MESSAGE */
.error-message {
    color: #d32f2f;
    font-size: 13px;
    margin-top: 10px;
    text-align: center;
    animation: shake 0.3s ease;
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-5px);
    }

    75% {
        transform: translateX(5px);
    }
}

/* SIGNUP LINK */
.signup-link {
    text-align: center;
    margin-top: 20px;
    color: #666;
    font-size: 14px;
}

    .signup-link a {
        color: #0f3460;
        text-decoration: none;
        font-weight: 600;
        transition: color 0.3s ease;
    }

        .signup-link a:hover {
            color: #ff0000;
        }

/* RESPONSIVE */
@media (max-width: 480px) {
    .container {
        padding: 30px 20px;
        margin: 20px;
    }

    .company-name {
        font-size: 20px;
    }

    h1 {
        font-size: 22px;
    }
}
/* Lỗi dưới mỗi input */
.field-error {
    color: #d32f2f;
    font-size: 13px;
    margin-top: 5px;
    text-align: left;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-3px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}