.header{position:fixed;top:0;left:0;right:0;z-index:var(--z-index-header);height:var(--header-height);transition:var(--transition-all)}.header__container{width:100%;height:100%;padding:0 var(--spacing-4);display:flex;align-items:center;justify-content:space-between;background-color:color-mix(in srgb,var(--current-bg) 80%,transparent);backdrop-filter:var(--backdrop-blur-xl);-webkit-backdrop-filter:var(--backdrop-blur-xl);border-bottom:1px solid var(--current-border)}.header--scrolled .header__container{box-shadow:var(--shadow-lg)}.header__brand{display:flex;align-items:center;margin-left:-.5rem}.header__brand-link{display:flex;align-items:center;text-decoration:none;color:inherit;transition:var(--transition-all)}.header__brand-link:hover{transform:scale(1.05)}.header__logo{width:11rem;height:6rem;border-radius:var(--border-radius-lg);background:transparent;display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden;flex-shrink:0;min-width:11rem;min-height:6rem}.header__logo img{width:100%;height:100%;-o-object-fit:contain;object-fit:contain;-o-object-position:center;object-position:center;display:block}:root[data-theme=light] .header__logo{background:transparent}.header__logo-text{font-size:var(--font-size-xl);font-weight:var(--font-weight-bold);color:white;z-index:1;position:relative}.header__logo-image{width:100%;height:100%;-o-object-fit:contain;object-fit:contain;-o-object-position:center;object-position:center;z-index:1;position:relative;transition:transform .3s ease}.header__brand-text{line-height:1.1;margin-left:var(--spacing-3);justify-content:center}.header__brand-main{font-size:var(--font-size-2xl);margin:0;padding:0}.header__brand-sub{font-weight:var(--font-weight-medium);margin:0;padding:0;letter-spacing:.1em}.header__brand-link:hover .header__logo-image{transform:scale(1.05)}.header__brand-text{display:flex;flex-direction:column;line-height:1.2;text-align:left}.header__brand-main{font-size:var(--font-size-xl);font-weight:var(--font-weight-bold);color:var(--current-text-primary);font-feature-settings:"kern" 1}.header__brand-main,.header__brand-sub{transition:var(--transition-colors);text-align:left;vertical-align:baseline;text-rendering:optimizeLegibility}.header__brand-sub{font-size:var(--font-size-sm);font-weight:var(--font-weight-normal);color:var(--current-text-secondary);font-feature-settings:"kern" 1}:root[lang=zh] .header__brand-main,:root[lang=zh] .header__brand-sub{font-feature-settings:"kern" 1,"liga" 1;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;letter-spacing:-.01em}.header__nav{display:none}@media (min-width:768px){.header__nav{display:block}}.header__nav-list{display:flex;align-items:center;gap:var(--spacing-8);list-style:none;margin:0;padding:0}[lang=en] .header__nav-list{gap:var(--spacing-6)}.header__nav-item{position:relative}.header__dropdown-icon{margin-left:.25rem;font-size:.75rem;width:.75rem;height:.75rem;display:inline-flex;align-items:center;justify-content:center;transition:transform var(--transition-duration-300) var(--transition-timing-ease-in-out)}.header__nav-item:hover .header__dropdown-icon{transform:rotate(180deg)}.header__nav-link{color:var(--current-text-secondary);text-decoration:none;font-weight:var(--font-weight-medium);transition:var(--transition-colors);position:relative;padding:var(--spacing-2) 0}[lang=en] .header__nav-link{font-size:.875rem;padding:var(--spacing-1) 0;letter-spacing:-.025em}.header__nav-link:hover{color:var(--color-primary)}:root[data-theme=light] .header__nav-link:hover{color:var(--color-primary-light)}.header__nav-link.active{color:var(--current-text-primary)}.header__nav-link:after{content:"";position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--gradient-primary);transition:width var(--transition-duration-300)}:root[data-theme=light] .header__nav-link:after{background:var(--gradient-light)}.header__nav-link.active:after,.header__nav-link:hover:after{width:100%}.header__dropdown{position:absolute;top:100%;left:50%;transform:translateX(-50%);background:var(--current-card);border:1px solid var(--current-border);border-radius:var(--border-radius-lg);box-shadow:var(--shadow-xl);padding:var(--spacing-2) 0;min-width:200px;opacity:0;visibility:hidden;transform:translateX(-50%) translateY(-10px);transition:all var(--transition-duration-300) var(--transition-timing-ease-in-out);z-index:1000}.header__dropdown.active{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0)}.header__dropdown-list{list-style:none;margin:0;padding:0}.header__dropdown-item{margin:0}.header__dropdown-link{display:block;padding:var(--spacing-3) var(--spacing-4);color:var(--current-text-secondary);text-decoration:none;font-size:var(--font-size-sm);font-weight:var(--font-weight-medium);transition:all var(--transition-duration-300) var(--transition-timing-ease-in-out);position:relative}.header__dropdown-link:hover{color:var(--color-primary);background:var(--current-surface)}:root[data-theme=light] .header__dropdown-link:hover{color:var(--color-primary-light)}.header__actions{display:flex;align-items:center;gap:var(--spacing-3)}[lang=en] .header__actions{gap:var(--spacing-2)}.header__action-btn{width:2.5rem;height:2.5rem;border-radius:50%;border:none;background:transparent;color:var(--current-text-secondary);display:flex;align-items:center;justify-content:center;cursor:pointer;transition:var(--transition-all);position:relative}.header__action-btn svg{width:1.25rem!important;height:1.25rem!important;font-size:1.25rem!important;display:block!important}.header__action-btn:hover{background-color:var(--current-surface);color:var(--color-primary);transform:scale(1.1)}:root[data-theme=light] .header__action-btn:hover{color:var(--color-primary-light)}.header__action-btn:active{transform:scale(.95)}.header__login-btn,.header__register-btn{display:none}@media (min-width:768px){.header__login-btn,.header__register-btn{display:inline-flex}}[lang=en] .header__login-btn,[lang=en] .header__register-btn{font-size:.75rem;padding:var(--spacing-1) var(--spacing-3)}[lang=en] .header__dropdown-link{font-size:.8rem;padding:var(--spacing-2) var(--spacing-3)}[lang=en] .header__dropdown{min-width:180px}.header__mobile-toggle{display:flex;width:2.5rem;height:2.5rem;border:none;background:transparent;color:var(--current-text-secondary);align-items:center;justify-content:center;cursor:pointer;transition:var(--transition-all)}@media (min-width:768px){.header__mobile-toggle{display:none}}.header__mobile-toggle:hover{color:var(--color-primary);background-color:var(--current-surface)}:root[data-theme=light] .header__mobile-toggle:hover{color:var(--color-primary-light)}.header__mobile-menu{display:none;position:absolute;top:100%;left:0;right:0;background-color:var(--current-card);border-bottom:1px solid var(--current-border);box-shadow:var(--shadow-lg);backdrop-filter:var(--backdrop-blur-xl);-webkit-backdrop-filter:var(--backdrop-blur-xl);opacity:0;transform:translateY(-10px);transition:all var(--transition-duration-300)}.header__mobile-menu.active{display:block;opacity:1;transform:translateY(0)}@media (min-width:768px){.header__mobile-menu{display:none!important}}.header__mobile-menu-content{padding:var(--spacing-4);display:flex;flex-direction:column;gap:var(--spacing-6)}.header__mobile-nav-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:var(--spacing-3)}.header__mobile-nav-link{color:var(--current-text-secondary);text-decoration:none;font-weight:var(--font-weight-medium);padding:var(--spacing-2) 0;transition:var(--transition-colors);display:block}.header__mobile-nav-link:hover{color:var(--color-primary)}:root[data-theme=light] .header__mobile-nav-link:hover{color:var(--color-primary-light)}.header__mobile-nav-link.active{color:var(--current-text-primary)}.header__mobile-backdrop{position:fixed;top:var(--header-height);left:0;right:0;bottom:0;background-color:rgba(0,0,0,.5);z-index:calc(var(--z-index-header) - 1);opacity:0;animation:fadeIn var(--transition-duration-300) forwards}@keyframes fadeIn{to{opacity:1}}@media (max-width:767px){.header__logo{width:3.5rem;height:3.5rem}.header__brand-text{margin-left:var(--spacing-2)}.header__brand-main{font-size:var(--font-size-lg)}.header__brand-sub{font-size:var(--font-size-xs)}}@media (min-width:640px){.header__container{padding:0 var(--spacing-6)}}@media (min-width:1024px){.header__container{padding:0 var(--spacing-8)}.header__nav-list{gap:var(--spacing-8)}}:root[data-theme=light] .header__mobile-backdrop{background-color:rgba(255,255,255,.8)}@media (prefers-reduced-motion:reduce){.header,.header__action-btn,.header__brand-link,.header__mobile-menu,.header__mobile-toggle,.header__nav-link{transition:none}}@media print{.header{position:static;box-shadow:none}.header__actions,.header__mobile-toggle{display:none}}