/* css/topbar.css */
.topbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--topbar-height);
    background: rgba(10, 31, 10, 0.6);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    z-index: 9999;
    transition: background var(--transition-standard), backdrop-filter var(--transition-standard);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 60px;
    border-bottom: 1px solid rgba(143, 191, 95, 0.15);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.topbar.scrolled {
    background: var(--color-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid var(--color-border);
}

.topbar-logo a {
    display: flex;
    align-items: center;
    font-family: var(--font-english-serif);
    font-size: 28px;
    color: var(--color-text-primary);
    font-weight: 700;
    letter-spacing: 2px;
}

.topbar-logo img {
    height: 50px;
    margin-right: 15px;
    object-fit: contain;
}

.topbar-nav {
    display: flex;
    gap: 40px;
}

.nav-item {
    position: relative;
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 22px;
}

.nav-link {
    color: #E8F5E9;
    padding: 10px 0;
    display: block;
    transition: color var(--transition-standard);
    font-weight: 500;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background-color: var(--color-accent);
    transition: width var(--transition-standard);
    box-shadow: 0 0 10px var(--color-accent);
}

.nav-item:hover .nav-link,
.nav-item.active .nav-link {
    color: var(--color-accent);
    text-shadow: 0 0 10px rgba(255, 215, 0, 0.3);
}

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

/* Submenu */
.submenu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background: var(--color-bg-card);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 15px 0;
    min-width: 160px;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-standard);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.nav-item:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.submenu-item a {
    display: block;
    padding: 10px 25px;
    color: #E8F5E9;
    font-size: 20px;
    white-space: nowrap;
    transition: all var(--transition-standard);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.submenu-item a:hover {
    background: rgba(255, 215, 0, 0.1);
    color: var(--color-accent);
}

/* Fullscreen Button */
.fullscreen-btn {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-standard);
    margin-left: 20px;
}

.fullscreen-btn:hover {
    background: rgba(255, 215, 0, 0.1);
    color: var(--color-accent);
    border-color: var(--color-accent);
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.3);
}

.fullscreen-btn svg {
    transition: transform var(--transition-standard);
}

.fullscreen-btn:hover svg {
    transform: scale(1.1);
}

/* Refresh Button */
.refresh-btn {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-standard);
    margin-left: 12px;
}

.refresh-btn:hover {
    background: rgba(255, 215, 0, 0.1);
    color: var(--color-accent);
    border-color: var(--color-accent);
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.3);
}

.refresh-btn svg {
    transition: transform 0.5s ease;
}

.refresh-btn:hover svg {
    transform: rotate(180deg);
}

/* Close Button */
.close-btn {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-standard);
    margin-left: 12px;
}

.close-btn:hover {
    background: rgba(255, 215, 0, 0.1);
    color: var(--color-accent);
    border-color: var(--color-accent);
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.3);
}

.close-btn svg {
    transition: transform var(--transition-standard);
}

.close-btn:hover svg {
    transform: scale(1.1);
}

/* BGM Button & Control Wrapper */
.bgm-control {
    position: relative;
    display: flex;
    align-items: center;
    margin-right: 12px;
}

.bgm-btn {
    background: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-standard);
    z-index: 2;
}

.bgm-btn:hover {
    background: rgba(255, 215, 0, 0.1);
    color: var(--color-accent);
    border-color: var(--color-accent);
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.3);
}

.bgm-btn svg {
    transition: transform 0.3s ease;
}

.bgm-btn:hover svg {
    transform: scale(1.1);
}

.bgm-volume-slider {
    position: absolute;
    top: 50%;
    right: 100%;
    transform: translateY(-50%) translateX(20px);
    background: rgba(20, 30, 20, 0.85);
    border: 1px solid var(--color-border);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 40px;
    padding: 0 16px 0 20px;
    height: 40px;
    display: flex;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
    z-index: 1;
    pointer-events: none;
}

.bgm-control:hover .bgm-volume-slider {
    opacity: 1;
    visibility: visible;
    transform: translateY(-50%) translateX(10px);
    pointer-events: auto;
}

.volume-range {
    -webkit-appearance: none;
    appearance: none;
    width: 80px;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}

.volume-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--color-accent);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
    transition: transform 0.2s;
}

.volume-range::-webkit-slider-thumb:hover {
    transform: scale(1.3);
}

.topbar-actions {
    display: flex;
    align-items: center;
}