.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    width: 100%;
    min-height: var(--layout-header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-32);
    padding: 0 clamp(var(--layout-gutter-mobile), 8.5vw, var(--layout-gutter));
    background: rgba(248, 250, 252, 0.78);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    transition:
        min-height var(--transition-base),
        padding var(--transition-base),
        gap var(--transition-base),
        background-color var(--transition-base);
}

.site-header.is-scrolled {
    min-height: 82px;
}

.logo {
    display: inline-flex;
    align-items: center;
    width: 162px;
    text-decoration: none;
    transition: width var(--transition-base);
}

.site-header.is-scrolled .logo {
    width: 136px;
}

.logo img {
    width: 100%;
    height: auto;
    display: block;
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--space-40);
    transition: gap var(--transition-base);
}

.menu-toggle {
    display: none;
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--space-32);
    font: var(--font-label);
}

.nav a {
    position: relative;
    padding: var(--space-8) 0;
    color: var(--color-text);
    text-decoration: none;
    text-underline-offset: var(--space-6);
    transition:
        color var(--transition-base),
        padding var(--transition-base),
        text-decoration-color var(--transition-base);
}

.nav a::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: var(--space-1);
    background: currentColor;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 260ms var(--ease-out);
}

.nav a:hover,
.nav a.active {
    color: var(--color-surface);
}

.nav a:hover {
    text-decoration: none;
}

.nav a:hover::after {
    transform: scaleX(1);
}

.nav a.active::after {
    animation: active-page-line 420ms var(--ease-out) both;
}

.quote-link {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--button-gap);
    min-height: var(--button-height-lg);
    padding: 0 var(--space-32);
    overflow: hidden;
    border-radius: var(--radius);
    color: var(--color-text-inverse);
    background:
        linear-gradient(110deg, var(--color-action), #2F5BEA, var(--color-action-hover), var(--color-action));
    background-size: 280% 100%;
    font: var(--font-label);
    white-space: nowrap;
    flex: 0 0 auto;
    text-decoration: none;
    transform-origin: center;
    transition:
        min-height var(--transition-base),
        padding var(--transition-base),
        transform var(--transition-base),
        box-shadow var(--transition-base);
    animation: quote-button-color 4s var(--ease-out) infinite;
}

.site-header.is-scrolled .quote-link {
    min-height: var(--button-height-md);
}

.quote-link span,
.quote-link-icon {
    position: relative;
    z-index: 1;
}

.quote-link-icon {
    width: 16px;
    height: 16px;
    display: block;
    flex: 0 0 auto;
    filter: brightness(0) invert(1);
}

.quote-link:hover {
    transform: scale(1.04);
    box-shadow: 0 10px 24px rgba(29, 78, 216, 0.18);
}

.quote-link::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(100deg, transparent 0 24%, rgba(255, 255, 255, 0.22) 42%, transparent 62% 100%);
    transform: translateX(-120%);
    animation: quote-button-light 2.8s var(--ease-out) infinite;
    pointer-events: none;
}

@media (max-width: 900px) {
    .site-header {
        min-height: 92px;
        align-items: center;
        gap: var(--space-20);
        padding-block: var(--space-20);
    }

    .site-header.is-scrolled {
        min-height: 76px;
        padding-block: var(--space-12);
    }

    .logo {
        width: 136px;
    }

    .site-header.is-scrolled .logo {
        width: 118px;
    }

    .menu-toggle {
        width: 48px;
        height: 48px;
        display: inline-flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: var(--space-6);
        margin-left: auto;
        border: var(--border-width) solid var(--color-border);
        border-radius: var(--radius);
        background: transparent;
        transition:
            border-color var(--transition-base),
            background-color var(--transition-base);
    }

    .menu-toggle:hover {
        border-color: var(--color-border-brand);
        background: var(--color-primary-60);
    }

    .menu-toggle span {
        width: 22px;
        height: var(--border-width-strong);
        border-radius: 999px;
        background: var(--color-text);
        transform-origin: center;
        transition:
            opacity var(--transition-base),
            transform var(--transition-base),
            background-color var(--transition-base);
    }

    .site-header.is-menu-open .menu-toggle {
        border-color: var(--color-border-brand);
    }

    .site-header.is-menu-open .menu-toggle span {
        background: var(--color-action);
    }

    .site-header.is-menu-open .menu-toggle span:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .site-header.is-menu-open .menu-toggle span:nth-child(2) {
        opacity: 0;
    }

    .site-header.is-menu-open .menu-toggle span:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .header-right {
        position: absolute;
        top: 100%;
        left: clamp(var(--layout-gutter-mobile), 8.5vw, var(--layout-gutter));
        right: clamp(var(--layout-gutter-mobile), 8.5vw, var(--layout-gutter));
        max-height: 0;
        overflow: hidden;
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-24);
        padding: 0 var(--space-24);
        border: var(--border-width) solid transparent;
        border-radius: var(--radius);
        background: var(--color-bg);
        box-shadow: 0 24px 60px rgba(15, 23, 42, 0.08);
        opacity: 0;
        pointer-events: none;
        transform: translateY(-8px);
        transition:
            max-height 280ms var(--ease-out),
            opacity var(--transition-base),
            padding var(--transition-base),
            transform var(--transition-base),
            border-color var(--transition-base);
    }

    .site-header.is-menu-open .header-right {
        max-height: 360px;
        padding-block: var(--space-24);
        border-color: var(--color-border);
        opacity: 1;
        pointer-events: auto;
        transform: translateY(0);
    }

    .nav {
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-12);
    }

    .nav a {
        padding: var(--space-12) 0;
    }

    .quote-link {
        width: 100%;
        min-height: var(--button-height-md);
    }
}

@keyframes active-page-line {
    from {
        transform: scaleX(0);
    }

    to {
        transform: scaleX(1);
    }
}

@keyframes quote-button-color {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

@keyframes quote-button-light {
    0%,
    35% {
        transform: translateX(-120%);
    }

    80%,
    100% {
        transform: translateX(120%);
    }
}