/* Main Header Styles */
.main-header {
    text-align: center;
    padding: 1.5rem 1rem;
    background: rgba(10, 25, 41, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 25px rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid var(--border-color);
    transform: translateZ(0);
    will-change: transform;
    /* 动态头部阴影效果 */
    transition: box-shadow 0.3s var(--transition-timing);
}

/* 动态头部阴影效果 - 滚动时 */
.main-header.scrolled {
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6);
}

/* 发光标题效果 */
.glowing-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    background: linear-gradient(45deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 0 20px var(--shadow-color), 0 0 30px rgba(0, 225, 255, 0.2);
    animation: titleGlow 2s var(--transition-timing) infinite alternate;
    letter-spacing: 0.08em;
    transform: translateZ(0);
    font-weight: bold;
}

.header-sub {
    color: var(--text-secondary);
    letter-spacing: 3px;
    margin-top: 0.6rem;
    font-size: clamp(1rem, 2vw, 1.3rem);
    opacity: 0.8;
}