[Code scan] Add accessible names to mobile menu controls

[njzjz]

This issue is a result of a Codex global code scan of deepmodeling/deepmodeling_sphinx at commit 156679f.

Problem

The mobile menu open and close controls are empty anchor elements that rely on background images. They do not have text content or aria-label attributes, so assistive technologies can expose them as unnamed links.

Code references:

deepmodeling_sphinx/deepmodeling_sphinx/banner.html

Lines 56 to 60 in 156679f

	<a
	class="main-menu-open-button"
	href="#"
	data-behavior="open-mobile-menu"
	></a>

deepmodeling_sphinx/deepmodeling_sphinx/banner.html

Lines 74 to 78 in 156679f

	<a
	class="main-menu-close-button"
	href="#"
	data-behavior="close-mobile-menu"
	></a>

deepmodeling_sphinx/deepmodeling_sphinx/banner.css

Lines 274 to 286 in 156679f

	.main-menu-close-button {
	background-image: url("https://unpkg.com/@njzjz/icons@0.0.5/deepmodeling/icon-close-opt.svg");
	background-position: center center;
	background-repeat: no-repeat;
	background-size: 1.5rem 1.5rem;
	height: 2.75rem;
	position: absolute;
	right: 0;
	width: 2.75rem;
	top: 0;
	border-radius: var(--dm-radius-pill);
	background-color: rgba(255, 255, 255, 0.08);
	}

deepmodeling_sphinx/deepmodeling_sphinx/banner.css

Lines 459 to 472 in 156679f

	.main-menu-open-button {
	background-image: url("https://unpkg.com/@njzjz/icons@0.0.5/deepmodeling/icon-menu-dots-dark-opt.svg");
	background-position: center center;
	background-size: 1.55rem 0.45rem;
	background-repeat: no-repeat;
	width: 2.75rem;
	height: 2.75rem;
	position: absolute;
	right: 0;
	top: 50%;
	transform: translateY(-50%);
	border-radius: var(--dm-radius-pill);
	background-color: var(--dm-surface-raised);
	}

Impact

Screen-reader and voice-control users may not be able to identify or operate the menu controls reliably.

Suggested fix

Use <button> elements for these controls, or add accessible names such as aria-label="Open menu" and aria-label="Close menu". The open control should also expose menu state with aria-expanded and reference the controlled menu where practical.