/*------------------------------------------
Header Styles
---------------------------------------------*/
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    padding-top: var(--space-m);
    padding-bottom: var(--space-m);
    background-color: var(--color-white);
}

.site-header .row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.site-header .brand {
    display: flex;
    width: 120px;
    align-items: center;

}

.site-header .brand .mark {
    width: 34px;
    height: 34px;
    border: 2px solid var(--accent);
    border-radius: var(--border-radius-form-mark);
    display: grid;
    place-items: center;
    font-size: 12px;
}

.site-header nav ul {
    display: flex;
    gap: 22px;
    list-style: none;
    padding: 0;
    margin: 0;
}

/* スマートフォンでのナビゲーション縦並び */
@media (max-width: 980px) {
    .site-header nav ul {
        flex-direction: column;
        gap: 0;
    }
}

.site-header nav a {
    text-decoration: none;
    font-size: var(--font-size-default);
    font-weight: var(--font-weight-bold);
}

.header-ctas {
    display: flex;
    gap: 10px;
}

/* Header Scroll Effects */
.site-header.scrolled {
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(8px);
    background: rgba(255, 255, 255, 0.95);
}

/*------------------------------------------
Mobile Menu Toggle Button
---------------------------------------------*/
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 30px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 60;
}

.mobile-menu-toggle span {
    width: 100%;
    height: 3px;
    background-color: var(--color-text);
    border-radius: 2px;
    transition: all 0.3s ease;
    transform-origin: center;
}

/* Hamburger animation */
.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/*------------------------------------------
Mobile Menu Overlay
---------------------------------------------*/
.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 40;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    pointer-events: none;
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

/*------------------------------------------
Mobile Menu
---------------------------------------------*/
.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background-color: var(--color-white);
    z-index: 50;
    transition: right 0.3s ease;
    overflow-y: auto;
    padding: 80px 0 40px;
    box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
    transform: translateZ(0); /* ハードウェアアクセラレーション */
}

.mobile-menu.active {
    display: block;
    right: 0;
}

.mobile-menu ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.mobile-menu li {
    border-bottom: 1px solid var(--color-border);
}

.mobile-menu a {
    display: block;
    padding: 16px 24px;
    text-decoration: none;
    color: var(--color-text);
    font-size: var(--font-size-default);
    font-weight: var(--font-weight-medium);
    transition: background-color 0.2s ease;
}

.mobile-menu a:hover {
    background-color: var(--color-bg-light);
}

.mobile-menu-ctas {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    border-top: 1px solid var(--color-border);
    margin-top: 20px;
}

/*------------------------------------------
Responsive Design
---------------------------------------------*/
@media (max-width: 980px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .header-right {
        display: none;
    }
    
    .site-header .row {
        padding: 0 var(--space-m);
    }
    
    .site-header {
        padding-top: var(--space-s);
        padding-bottom: var(--space-s);
    }
}