/* ================================================== */
/* 文件 4: css/responsive.css (响应式)                 */
/* ================================================== */
@media (max-width: 1200px) {
    .hero h1 { font-size: 5rem; }
}
@media (max-width: 900px) {
    .hero h1 { font-size: 4rem; }
    .nav-links { display: none; } /* 移动端简化，后续可加汉堡菜单 */
    .about-grid { grid-template-columns: 1fr; }
    .investment-content { grid-template-columns: 1fr; }
    .avatar-frame { width: 250px; height: 250px; }
}
@media (max-width: 600px) {
    .hero h1 { font-size: 3.2rem; }
    .hero .subheadline { font-size: 1.2rem; }
    .section-title h2 { font-size: 2.5rem; }
}