body {
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #1e293b, #0f172a);
    font-family: Arial, sans-serif;
    height: 100vh;
}

#login {
    width: 380px;
    margin: 80px auto;
    padding: 35px;
    background: #ffffff;
    border-radius: 14px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

#login h1 {
    text-align: center;
    margin-bottom: 30px;
    color: #1e293b;
    font-size: 34px;
    font-weight: bold;
}

.input-prepend {
    position: relative;
    margin-bottom: 22px;
}

.input-prepend .add-on {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: #64748b;
    font-size: 18px;
    z-index: 2;
}

.input-prepend input {
    width: 100%;
    height: 52px;
    padding: 0 15px 0 48px;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    font-size: 15px;
    background: #f8fafc;
    box-sizing: border-box;
    transition: all 0.25s ease;
}

.input-prepend input:focus {
    outline: none;
    border-color: #2563eb;
    background: #ffffff;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.15);
}

.input-prepend input::placeholder {
    color: #94a3b8;
}

.btn-login {
    width: 100%;
    height: 52px;
    border: none;
    border-radius: 10px;
    background: #2563eb;
    color: white;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.25s ease;
}

.btn-login:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.btn-login:active {
    transform: scale(0.98);
}

.alert {
    padding: 12px;
    margin-bottom: 18px;
    border-radius: 8px;
    background: #fee2e2;
    color: #b91c1c;
    text-align: center;
    font-size: 14px;
}