/* --- General Header Styling --- */
        #site-header {
            background-color: var(--hah-surface);
            border-bottom: 1px solid var(--hah-border);
            padding: 0.5rem 0;
        }

        /* --- Desktop Header --- */
        .header-desktop {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        
        .header-right-content {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        /* --- Search Form Styling --- */
        .header-search-form {
            position: relative;
            width: 100%;
        }

        .header-desktop .header-search-form {
             width: 450px;
        }

        .header-search-form .search-logo {
            position: absolute;
            left: 12px;
            top: 50%;
            transform: translateY(-50%);
            width: 32px;
            height: 32px;
            max-width: 32px;
            max-height: 32px;
            object-fit: contain;
            min-height: 0;
            z-index: 4;
        }
        
        .header-search-form .form-control {
            padding-left: 55px;
            height: 44px;
            border-radius: 10px;
            font-size: 16px;
            border: 1px solid #ccc;
            transition: border-color 0.2s ease-in-out;
            box-sizing: border-box;
        }
        .header-search-form .form-control:focus {
            outline: none;
            border-color: var(--hah-brand);
            box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        /* Spinner loading */
        .search-spinner {
            position: absolute;
            right: 15px;
            top: 50%;
            transform: translateY(-50%);
            width: 20px;
            height: 20px;
            border: 2px solid #adb5bd;
            border-top-color: var(--hah-brand);
            border-radius: 50%;
            animation: spin 1s linear infinite;
            display: none;
        }
        
        @keyframes spin {
            to { transform: translateY(-50%) rotate(360deg); }
        }

        /* --- Dropdown kết quả (Phong cách mới) --- */
        .search-results-dropdown {
            position: absolute;
            top: 110%;
            left: 0;
            right: 0;
            background: #fff;
            border-radius: 10px;
            border: 1px solid var(--hah-border);
            box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
            z-index: 1000;
            display: none;
            padding: 7px;
            max-height: 70vh;
            overflow-y: auto;
        }

        .search-results-dropdown.show {
            display: block;
        }

        .search-results-dropdown .autocomplete-result a {
            display: block;
            padding: 10px;
            color: #212529;
            text-decoration: none;
            border-radius: 6px;
            transition: background-color 0.2s ease;
        }
        
        .search-results-dropdown .autocomplete-result a:hover {
            background-color: #e9ecef;
        }
        
        .search-results-dropdown .ac-title-text {
            font-weight: 600;
            display: block;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        .search-results-dropdown .ac-description {
            font-size: 13px;
            color: #6c757d;
            display: block;
            margin-top: 3px;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }
        
        .search-results-dropdown .ac-description i {
            margin-right: 5px;
        }
        
        .search-results-dropdown .ac-harmony {
            font-size: 13px;
            color: var(--hah-brand);
            font-weight: 500;
            margin-top: 5px;
            font-family: monospace;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }
        .search-results-dropdown .ac-harmony i {
            margin-right: 5px;
        }

        .search-results-dropdown .ac-lyric {
            font-size: 13px;
            color: #6c757d;
            margin-top: 4px;
            line-height: 1.4;
            font-style: italic;
        }
        
        .search-results-dropdown .see-all {
            padding: 10px;
            text-align: center;
            font-size: 13px;
            color: #6c757d;
            border-top: 1px solid #e9ecef;
            margin-top: 5px;
        }
        
        .search-results-dropdown .no-results {
            padding: 15px;
            color: #6c757d;
            text-align: center;
        }

        /* --- Mobile Header & Overlay --- */
        .header-mobile {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        .mobile-logo img {
            width: 32px;
            height: 32px;
            max-width: 32px;
            max-height: 32px;
            object-fit: contain;
            min-height: 0;
            display: block;
        }
        .mobile-actions button {
            background: none;
            border: none;
            font-size: 1.5rem;
            color: #343a40;
        }
        .navbar-toggler-icon {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(33, 37, 41, 0.75)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
        }
        #main-nav-mobile .mobile-user-actions {
            border-top: 1px solid var(--hah-border);
            padding-top: 1rem !important;
            margin-top: 1rem;
        }
        #main-nav-mobile .mobile-user-actions .btn {
            font-weight: 500;
        }
        #main-nav-mobile .mobile-user-actions .nav-link-user {
            font-weight: 500;
            color: #212529;
            display: block;
            padding: .5rem 0;
        }
        .mobile-search-overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(255,255,255,0.9);
            backdrop-filter: blur(5px);
            z-index: 1040;
            padding: 1rem;
        }
        .mobile-search-overlay.active {
            display: flex;
            align-items: flex-start;
            justify-content: center;
        }
        .mobile-search-box {
            background: transparent;
            position: relative;
            width: 100%;
            max-width: 600px;
            margin-top: 10vh;
        }
        #close-mobile-search {
            position: absolute;
            top: -40px;
            right: 0px;
            font-size: 2rem;
            color: #333;
            background: none;
            border: none;
            cursor: pointer;
        }