ex-direction: column; align-items: center; } /* 顶部导航 */ header { width: 100%; padding: 15px; text-align: center; border-bottom: 2px solid var(--gold); background: radial-gradient(circle at center, #282828 0%, #0f0f0f 100%); } h1 { margin: 0; color: var(--gold); letter-spacing: 2px; font-size: 1.2rem; } .sub-nav { display: flex; justify-content: center; gap: 5px; margin-top: 10px; font-size: 0.7rem; color: var(--dim); } .step-dot { width: 8px; height: 8px; bord