.nav-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: clamp(50px, 8vw, 60px);
    background-color: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.nav-brand {
    position: absolute;
    left: clamp(10px, 2vw, 20px);
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    cursor: pointer;
}

.nav-brand span {
    font-size: clamp(14px, 1.5vw, 19px);
    font-weight: 700;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    letter-spacing: 1px;
    color: #fff;
}

.nav-brand img {
    width: clamp(32px, 4vw, 40px);
    height: clamp(32px, 4vw, 40px);
    margin-right: clamp(10px, 1.8vw, 16px);
}

.nav-item {
    position: relative;
    margin: 0 clamp(6px, 1.2vw, 15px);
    cursor: pointer;
    padding: clamp(5px, 0.8vw, 10px);
    color: #fff;
    font-weight: bold;
}

.nav-item::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: clamp(1.5px, 0.25vw, 2px);
    background-color: #fff;
    border-radius: 1px;
    transform: translateX(-50%);
    transition: width 0.3s ease;
}

.nav-item:hover::after {
    width: 100%;
}

.dropdown {
    position: absolute;
    top: calc(127% + 2px);
    left: 50%;
    transform: translateX(-50%) translateY(-10px);
    width: auto;
    max-width: 90vw;
    height: auto;
    background: rgba(30, 30, 30, 0.85);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    gap: clamp(4px, 0.6vw, 6px);
    padding: clamp(6px, 0.8vw, 8px) clamp(8px, 1vw, 12px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    z-index: 1001;
    text-align: left;
    border-radius: 10px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
    pointer-events: none;
}

.dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.menu-item {
    font-weight: bold;
    font-size: clamp(14px, 1.2vw, 19px);
    margin: 0;
    padding: clamp(4px, 0.5vw, 6px) clamp(6px, 0.8vw, 10px);
    white-space: nowrap;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 0.25s ease, transform 0.25s ease;
    color: #fff;
}

.dropdown.active .menu-item {
    opacity: 1;
    transform: translateY(0);
}

.dropdown.active .menu-item:nth-child(1) { transition-delay: 0.04s; }
.dropdown.active .menu-item:nth-child(2) { transition-delay: 0.08s; }
.dropdown.active .menu-item:nth-child(3) { transition-delay: 0.12s; }
.dropdown.active .menu-item:nth-child(4) { transition-delay: 0.16s; }
.dropdown.active .menu-item:nth-child(5) { transition-delay: 0.20s; }
.dropdown.active .menu-item:nth-child(6) { transition-delay: 0.24s; }
.dropdown.active .menu-item:nth-child(7) { transition-delay: 0.28s; }

.dropdown .menu-item:hover {
    color: #aaa;
    cursor: pointer;
}

.dropdown .menu-item:first-child {
    border-top-left-radius: 9px;
    border-top-right-radius: 9px;
}

.dropdown .menu-item:last-child {
    border-bottom-left-radius: 9px;
    border-bottom-right-radius: 9px;
}

.nav-buttons {
    position: absolute;
    right: clamp(10px, 2vw, 20px);
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    gap: clamp(6px, 1vw, 10px);
}

.nav-btn {
    background-color: #5b3ed9;
    color: #fff;
    border: 1px solid #000;
    border-radius: 9999px;
    padding: clamp(4px, 0.6vw, 6px) clamp(10px, 1.8vw, 18px);
    font-size: clamp(11px, 0.9vw, 14px);
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: clamp(60px, 7vw, 90px);
    white-space: nowrap;
    font-family: inherit;
}

.nav-btn:hover {
    background-color: #7b5ee9;
}

.nav-search-btn {
    width: clamp(34px, 3.5vw, 42px);
    height: clamp(34px, 3.5vw, 42px);
    border-radius: 50%;
    padding: 0;
    font-size: clamp(14px, 1.2vw, 18px);
    min-width: auto;
    border: 1px solid #000;
}

.search-box {
    position: fixed;
    top: clamp(55px, 9vw, 65px);
    left: 50%;
    transform: translateX(-50%) translateY(-10px);
    background: rgba(30, 30, 30, 0.85);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    padding: 0 clamp(12px, 2vw, 20px);
    height: clamp(36px, 4vw, 42px);
    display: flex;
    align-items: center;
    border-radius: 9999px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    border: 1px solid rgba(255, 255, 255, 0.15);
    z-index: 999;
    transition: transform 0.3s ease, opacity 0.3s ease, visibility 0.3s ease;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.search-box.active {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.search-input {
    width: clamp(200px, 30vw, 300px);
    height: 100%;
    border: none;
    outline: none;
    background: transparent;
    font-size: clamp(12px, 1vw, 16px);
    font-family: inherit;
    color: #fff;
}

/* 汉堡按钮 */
.hamburger {
    display: flex;
    width: clamp(34px, 3.5vw, 42px);
    height: clamp(34px, 3.5vw, 42px);
    border-radius: 50%;
    background-color: #5b3ed9;
    border: 1px solid #000;
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 0;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, background-color 0.2s ease;
}

.hamburger:hover {
    background-color: #7b5ee9;
}

/* 移动端导航栏圆形按钮组 */
.mobile-bar-actions {
    position: absolute;
    right: clamp(10px, 2vw, 20px);
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    gap: clamp(6px, 1vw, 10px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.mobile-icon-btn {
    display: flex;
    width: clamp(34px, 3.5vw, 42px);
    height: clamp(34px, 3.5vw, 42px);
    border-radius: 50%;
    background-color: #5b3ed9;
    border: 1px solid #000;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    padding: 0;
    color: #fff;
    text-decoration: none;
    font-family: inherit;
    transition: background-color 0.2s ease;
}

.mobile-icon-btn:hover {
    background-color: #7b5ee9;
}

.mobile-icon-btn .m-icon {
    width: clamp(18px, 2vw, 22px);
    height: clamp(18px, 2vw, 22px);
    pointer-events: none;
}

.hamburger span {
    display: block;
    width: 18px;
    height: 2px;
    background-color: #fff;
    border-radius: 2px;
}

/* 移动端菜单 */
.mobile-menu {
    position: fixed;
    top: clamp(50px, 8vw, 60px);
    left: 0;
    width: 100%;
    height: calc(100vh - clamp(50px, 8vw, 60px));
    background: rgba(20, 20, 20, 0.9);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    z-index: 998;
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    padding: clamp(16px, 3vw, 24px);
    box-sizing: border-box;
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.3s ease, opacity 0.3s ease, visibility 0.3s ease;
    pointer-events: none;
}

.mobile-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.mobile-group {
    margin-bottom: clamp(20px, 3vw, 28px);
}

.mobile-label {
    font-size: clamp(11px, 1.1vw, 13px);
    color: #aaa;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 10px;
    border-bottom: 1px solid #555;
    padding-bottom: 6px;
}

.m-item {
    margin-bottom: 6px;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.m-toggle {
    display: block;
    font-size: clamp(16px, 1.8vw, 20px);
    font-weight: bold;
    padding: 6px 0;
    color: #fff;
}

.m-sub {
    padding-left: 14px;
    margin-top: 2px;
}

.m-link {
    display: block;
    padding: 5px 0;
    color: #bbb;
    text-decoration: none;
    font-size: clamp(14px, 1.4vw, 16px);
}

.m-link:hover {
    color: #5b3ed9;
}

.mobile-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.mobile-act-btn {
    background-color: #5b3ed9;
    color: #fff;
    border: 1px solid #000;
    border-radius: 9999px;
    padding: clamp(8px, 1.2vw, 12px) clamp(16px, 2.5vw, 24px);
    font-size: clamp(13px, 1.3vw, 16px);
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    display: block;
    font-family: inherit;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.mobile-act-btn:hover {
    background-color: #7b5ee9;
}

/* 移动端菜单项依次出现动画 */
.mobile-menu.active .m-item {
    opacity: 1;
    transform: translateY(0);
}

.mobile-menu.active .mobile-act-btn {
    opacity: 1;
    transform: translateY(0);
}

/* 小屏响应式 */
@media (max-width: 848px) {
    .nav-item,
    .nav-buttons {
        display: none !important;
    }

    .mobile-bar-actions {
        opacity: 1;
        visibility: visible;
    }

    .hamburger {
        opacity: 1;
        visibility: visible;
    }
}