.shared-header-host {
    position: sticky;
    top: 0;
    z-index: 1000;
}

.shared-header {
    position: relative;
    border-bottom: 1px solid rgba(229, 231, 235, 0.72);
    background: rgba(255, 255, 255, 0.82);
    color: #171915;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.shared-header[data-theme="dark"] {
    border-bottom-color: rgba(31, 41, 55, 0.72);
    background: rgba(10, 10, 10, 0.82);
    color: #f2f3ed;
}

.shared-header *,
.shared-header *::before,
.shared-header *::after { box-sizing: border-box; }

.shared-header__inner {
    width: min(1280px, calc(100% - 32px));
    min-height: 64px;
    margin-inline: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.shared-header__brand {
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: inherit;
    font-size: 1.2rem;
    font-weight: 750;
    letter-spacing: -0.02em;
    text-decoration: none;
}

.shared-header__brand-mark {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    display: grid;
    place-items: center;
    background: #111111;
    color: #ffffff;
    font-family: Georgia, serif;
    font-size: 1rem;
    line-height: 1;
}
.shared-header[data-theme="dark"] .shared-header__brand-mark {
    background: #ffffff;
    color: #111111;
}

.shared-header__desktop-actions,
.shared-header__mobile-actions,
.shared-header__nav {
    display: flex;
    align-items: center;
}
.shared-header__desktop-actions { min-width: 0; gap: 4px; }
.shared-header__mobile-actions { display: none; gap: 8px; }
.shared-header__nav { gap: 4px; }
.shared-header__nav a {
    padding: 8px 14px;
    border-radius: 999px;
    color: #4b5563;
    font-size: 0.875rem;
    font-weight: 600;
    line-height: 1.25;
    text-decoration: none;
    white-space: nowrap;
    transition: color 180ms ease, background-color 180ms ease;
}
.shared-header__nav a:hover,
.shared-header__nav a[aria-current="page"] {
    background: #f3f4f6;
    color: #111827;
}
.shared-header[data-theme="dark"] .shared-header__nav a { color: #d1d5db; }
.shared-header[data-theme="dark"] .shared-header__nav a:hover,
.shared-header[data-theme="dark"] .shared-header__nav a[aria-current="page"] {
    background: #1f2937;
    color: #ffffff;
}

.shared-header__divider {
    width: 1px;
    height: 16px;
    margin-inline: 8px;
    background: #d1d5db;
}
.shared-header[data-theme="dark"] .shared-header__divider { background: #374151; }

.shared-header__icon-button {
    width: 36px;
    height: 36px;
    padding: 8px;
    border: 0;
    border-radius: 999px;
    display: inline-grid;
    place-items: center;
    background: transparent;
    color: #4b5563;
    cursor: pointer;
    transition: color 180ms ease, background-color 180ms ease;
}
.shared-header__icon-button:hover { background: #f3f4f6; color: #111111; }
.shared-header__icon-button:focus-visible { outline: 2px solid #356859; outline-offset: 2px; }
.shared-header[data-theme="dark"] .shared-header__icon-button { color: #d1d5db; }
.shared-header[data-theme="dark"] .shared-header__icon-button:hover { background: #1f2937; color: #ffffff; }
.shared-header__icon-button svg,
.shared-header__language-menu svg {
    width: 20px;
    height: 20px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.shared-header__language { position: relative; }
.shared-header__language-menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    width: 160px;
    padding-block: 4px;
    overflow: hidden;
    border: 1px solid #f3f4f6;
    border-radius: 12px;
    background: #ffffff;
    box-shadow: 0 18px 36px rgba(0, 0, 0, 0.14);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-8px);
    transform-origin: top right;
    transition: opacity 180ms ease, visibility 180ms ease, transform 180ms ease;
}
.shared-header__language:focus-within .shared-header__language-menu,
.shared-header__language.is-open .shared-header__language-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
}
.shared-header[data-theme="dark"] .shared-header__language-menu { border-color: #1f2937; background: #111827; }
.shared-header__language-menu button {
    width: 100%;
    padding: 9px 16px;
    border: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: transparent;
    color: #374151;
    cursor: pointer;
    font: inherit;
    font-size: 0.875rem;
    text-align: left;
}
.shared-header__language-menu button:hover { background: #f9fafb; }
.shared-header[data-theme="dark"] .shared-header__language-menu button { color: #e5e7eb; }
.shared-header[data-theme="dark"] .shared-header__language-menu button:hover { background: #1f2937; }
.shared-header__language-check { visibility: hidden; width: 14px !important; height: 14px !important; }
.shared-header__language-menu button[aria-pressed="true"] .shared-header__language-check { visibility: visible; }

.shared-header__theme-icon--sun,
.shared-header__menu-icon--close { display: none; }
.shared-header[data-theme="dark"] .shared-header__theme-icon--moon { display: none; }
.shared-header[data-theme="dark"] .shared-header__theme-icon--sun { display: block; }
[data-shared-menu-toggle][aria-expanded="true"] .shared-header__menu-icon--open { display: none; }
[data-shared-menu-toggle][aria-expanded="true"] .shared-header__menu-icon--close { display: block; }

.shared-header__mobile-menu {
    padding: 8px 16px 20px;
    border-top: 1px solid #f3f4f6;
    background: #ffffff;
    box-shadow: 0 18px 30px rgba(0, 0, 0, 0.08);
}
.shared-header[data-theme="dark"] .shared-header__mobile-menu { border-top-color: #1f2937; background: #111827; }
.shared-header__nav--mobile { display: grid; gap: 4px; }
.shared-header__nav--mobile a { padding: 10px 16px; border-radius: 8px; }
.shared-header__mobile-language { padding: 14px 16px 0; }
.shared-header__mobile-language > span {
    display: block;
    margin-bottom: 8px;
    color: #6b7280;
    font-size: 0.8rem;
}
.shared-header[data-theme="dark"] .shared-header__mobile-language > span { color: #9ca3af; }
.shared-header__mobile-language > div { display: flex; gap: 8px; }
.shared-header__mobile-language button {
    padding: 6px 12px;
    border: 0;
    border-radius: 6px;
    background: #f3f4f6;
    color: #111827;
    cursor: pointer;
    font: inherit;
    font-size: 0.82rem;
}
.shared-header__mobile-language button[aria-pressed="true"] { background: #111111; color: #ffffff; }
.shared-header[data-theme="dark"] .shared-header__mobile-language button { background: #1f2937; color: #e5e7eb; }
.shared-header[data-theme="dark"] .shared-header__mobile-language button[aria-pressed="true"] { background: #ffffff; color: #111111; }

body.has-shared-header { padding-top: 0; }

@media (max-width: 960px) {
    .shared-header__desktop-actions { display: none; }
    .shared-header__mobile-actions { display: flex; }
}