:root{--bg: #ffffff;--text: #333333;--muted: #888888;--nav-bg: #f8f9fa;--nav-shadow: rgba(0, 0, 0, .1);--card-border: #dddddd;--card-text: #444444}[data-theme=dark]{--bg: #121212;--text: #e0e0e0;--muted: #aaaaaa;--nav-bg: #1e1e1e;--nav-shadow: rgba(0, 0, 0, .5);--card-border: #333333;--card-text: #cccccc}body{margin:0;font-family:Arial,sans-serif;background-color:var(--bg);color:var(--text);transition:background-color .25s,color .25s}.red-bordered-heading{border:2px solid red}.navbar{padding:1rem;background-color:var(--nav-bg);display:flex;justify-content:flex-start;align-items:center;gap:20px;box-shadow:0 2px 5px var(--nav-shadow);font-weight:700;transition:background-color .25s,box-shadow .25s}.navbar-link{text-decoration:none;color:var(--text);transition:color .25s}.theme-toggle{margin-left:auto;background:none;border:1px solid var(--card-border);border-radius:4px;padding:.25rem .6rem;cursor:pointer;color:var(--text);font-size:1rem;transition:border-color .25s,color .25s}.theme-toggle:hover{border-color:var(--muted)}@media (max-width: 768px){.navbar{justify-content:space-around;gap:0;padding:.75rem .5rem}.navbar-link{flex:1;text-align:center;padding:.5rem 0}.theme-toggle{margin-left:0}}