.main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    background-color: #ffffff;
    border-bottom: 1px solid #e9ecef;
    padding: 10px 0;
    z-index: 1000;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.header-left,
.header-right {
    display: flex;
    align-items: center;
    gap: 15px;
    min-width: 300px;
}

.logo img {
    width: 70px;
    height: auto;
    vertical-align: middle;
}

.main-nav {
    margin-left: 30px;
}

.main-nav a {
    font-size: 18px;
    font-weight: 700;
    margin-right: 20px;
    color: #495057;
    text-decoration: none;
}

.main-nav a.active {
    color: #212529;
}

.search-bar {
    width: 250px;
    padding: 8px 12px;
    border: none;
    background-color: #f1f3f5;
    border-radius: 6px;
    font-size: 14px;
    align-self: center;
}

.search-bar:focus {
    outline: none;
    background-color: #e9ecef;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 36px;
    padding: 0 15px;
    font-size: 14px;
    font-weight: 700;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    text-decoration: none;
    white-space: nowrap;
    background-color: white;
    color: #495057;
    cursor: pointer;
    line-height: 1;
    box-sizing: border-box;
    vertical-align: middle;
}

.header-buttons {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: nowrap;
}

.header-buttons a,
.header-buttons form {
    display: flex;
    align-items: center;
    margin: 0;
}

.header-buttons .btn-chat {
    border-color: #ff8a3d;
    color: #ff8a3d;
    background-color: white;
}

.btn-login {
    background-color: #ff8a3d;
    color: white;
    border: 1px solid transparent;
}

.btn-login:hover {
    background-color: #fff5ec;
    color: #ff8a3d;
}

.btn-logout {
    background-color: #f2f3f6;
    color: #212529;
    border: 1px solid #ddd;
}

.btn:hover {
    opacity: 0.9;
    transition: opacity 0.2s ease-in-out;
}