/* =====================================================================
   崇業聯合會計師事務所 — Layout（容器 / Header / Footer / Nav）
   ===================================================================== */

.container {
    width: min(100% - 3rem, var(--container));
    margin-inline: auto;
}
.container-wide { width: min(100% - 3rem, var(--container-wide)); margin-inline: auto; }

.section { padding-block: var(--space-section); }
.section--soft { background: var(--bg-soft); }
.section--navy { background: var(--navy-800); color: #fff; }

/* ------------------------------------------------------------------ */
/* Header                                                              */
/* ------------------------------------------------------------------ */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 1000;
    height: 96px;
    display: flex;
    align-items: stretch;
    transition: background .4s var(--ease), height .4s var(--ease),
                box-shadow .4s var(--ease);
}
.site-header::after {
    content: "";
    position: absolute; inset: 0;
    background: transparent;
    transition: background .4s var(--ease);
    z-index: -1;
}
/* 透明起始（覆蓋於 Hero 上）*/
.site-header--transparent { color: #fff; }
.site-header--transparent .brand__zh { color: #fff; }
.site-header--transparent .brand__en { color: rgba(255,255,255,.75); }
.site-header--transparent .main-nav a { color: rgba(255,255,255,.9); }

/* 捲動後轉白底 */
.site-header.is-scrolled {
    height: 80px;
    background: rgba(255, 255, 255, .96);
    backdrop-filter: blur(10px);
    box-shadow: 0 6px 30px rgba(0, 118, 186, .10);
    color: var(--ink);
}
.site-header.is-scrolled .brand__zh { color: var(--navy-800); }
.site-header.is-scrolled .brand__en { color: var(--muted); }
.site-header.is-scrolled .main-nav a { color: var(--ink-soft); }

.header-inner {
    width: 100%;
    max-width: var(--container-wide);
    margin-inline: auto;
    padding-inline: clamp(1.25rem, 2.5vw, 2.5rem);
    display: flex;
    align-items: center;
    gap: 2rem;
    flex: 1;
    min-width: 0;
    box-sizing: border-box;
    transition: padding .4s var(--ease);
}

/* Logo / 品牌 —— 放大 */
.brand { display: flex; align-items: center; gap: .8rem; flex-shrink: 0; }
.brand__logo { height: 58px; width: auto; transition: height .4s var(--ease); }
.brand__logo--white { display: none; }
.site-header.is-scrolled .brand__logo { height: 50px; }

/* 透明（頂部，深色背景）→ 顯示白色 logo */
.site-header--transparent .brand__logo--color { display: none; }
.site-header--transparent .brand__logo--white { display: block; }
/* 捲動後（白底）→ 顯示彩色 logo */
.site-header.is-scrolled .brand__logo--color { display: block; }
.site-header.is-scrolled .brand__logo--white { display: none; }

/* 主選單 —— 與右側操作區一起靠右 */
.header-end {
    display: flex;
    align-items: center;
    gap: .65rem;
    margin-left: auto;
    min-width: 0;
}
.main-nav ul { display: flex; gap: 1.5rem; align-items: center; flex-wrap: nowrap; }
.main-nav a {
    position: relative;
    font-size: .95rem;
    font-weight: 600;
    padding: .4rem 0;
    color: var(--ink-soft);
    white-space: nowrap;
}
.main-nav a::after {
    content: "";
    position: absolute; left: 0; bottom: -2px;
    width: 0; height: 2px;
    background: var(--gold-500);
    transition: width .35s var(--ease);
}
.main-nav a:hover, .main-nav a[aria-current="page"] { color: var(--gold-600); }
.main-nav a:hover::after, .main-nav a[aria-current="page"]::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: .8rem; }

.header-search {
    display: none;
    position: relative;
    align-items: center;
    flex-shrink: 0;
    width: 44px;
    transition: width .35s var(--ease), flex .35s var(--ease);
}
.header-search__toggle {
    width: 44px;
    height: 44px;
    display: grid;
    place-items: center;
    border: 0;
    border-radius: 50%;
    background: transparent;
    color: currentColor;
    cursor: pointer;
    flex-shrink: 0;
    transition: background .3s var(--ease), opacity .25s var(--ease);
}
.header-search__toggle:hover {
    background: rgba(0, 144, 224, .14);
    color: var(--gold-600);
}
.header-search__form {
    display: none;
    align-items: center;
    gap: .35rem;
    width: 100%;
    padding: .35rem .45rem .35rem .85rem;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: rgba(255, 255, 255, .98);
    box-shadow: 0 8px 24px rgba(6, 52, 90, .12);
}
.header-search.is-open {
    width: 100%;
}
.header-search.is-open .header-search__toggle {
    display: none;
}
.header-search.is-open .header-search__form {
    display: flex;
}
.header-search.is-open .header-search__form:focus-within {
    border-color: rgba(0, 144, 224, .45);
    box-shadow: 0 0 0 3px rgba(0, 144, 224, .12), 0 8px 24px rgba(6, 52, 90, .12);
}
.header-search__form input {
    flex: 1;
    min-width: 0;
    width: 100%;
    border: 0;
    outline: none;
    background: transparent;
    font-size: .88rem;
    color: var(--ink);
    padding: .25rem 0;
}
.header-search__form input::placeholder { color: var(--muted); }
.header-search__submit {
    display: grid;
    place-items: center;
    width: 2rem;
    height: 2rem;
    border: 0;
    border-radius: 50%;
    background: transparent;
    color: var(--navy-800);
    cursor: pointer;
    transition: background .3s var(--ease), color .3s var(--ease);
}
.header-search__submit:hover {
    background: rgba(0, 144, 224, .12);
    color: var(--navy-500);
}

.site-header--transparent:not(.is-scrolled) .header-search__toggle:hover {
    background: rgba(255, 255, 255, .12);
    color: #fff;
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__form {
    background: rgba(6, 52, 90, .92);
    border-color: rgba(255, 255, 255, .22);
    backdrop-filter: blur(10px);
    box-shadow: 0 10px 28px rgba(0, 0, 0, .22);
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__form:focus-within {
    border-color: rgba(255, 255, 255, .4);
    box-shadow: 0 0 0 3px rgba(255, 255, 255, .12), 0 10px 28px rgba(0, 0, 0, .22);
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__form input {
    color: #fff;
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__form input::placeholder {
    color: rgba(255, 255, 255, .68);
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__submit {
    color: #fff;
}
.site-header--transparent:not(.is-scrolled) .header-search.is-open .header-search__submit:hover {
    background: rgba(255, 255, 255, .14);
    color: #fff;
}

@media (min-width: 1025px) {
    .header-search { display: flex; }
    .site-header.is-search-open .main-nav {
        display: none;
    }
    .site-header.is-search-open .header-end {
        flex: 1;
        min-width: 0;
    }
    .site-header.is-search-open .header-actions {
        flex: 1;
        justify-content: flex-end;
        min-width: 0;
    }
    .site-header.is-search-open .header-search {
        flex: 1;
        max-width: min(420px, calc(100vw - 22rem));
        min-width: 220px;
    }
}

.icon-btn {
    width: 44px; height: 44px;
    display: grid; place-items: center;
    border-radius: 50%;
    color: currentColor;
    transition: background .3s var(--ease), color .3s var(--ease);
}
.icon-btn:hover { background: rgba(0, 144, 224, .14); color: var(--gold-600); }

/* 漢堡選單 —— 右側品牌藍色塊（參考站風格，改用 Logo 藍）*/
.nav-toggle {
    display: none;
    flex-shrink: 0;
    width: 96px;
    align-self: stretch;
    place-items: center;
    background: var(--navy-500);
    color: #fff;
    border-radius: 0;
    box-shadow: none;
    transition: background .3s var(--ease), width .4s var(--ease), filter .3s var(--ease);
}
.nav-toggle:hover { background: var(--navy-600); filter: brightness(1.05); }
.nav-toggle .ico { stroke-width: 2.2; }

/* 頂部未捲動：漢堡無底色（透明 Header 上顯示白線條）*/
.site-header:not(.is-scrolled) .nav-toggle {
    background: transparent;
    color: #fff;
    filter: none;
}
.site-header:not(.is-scrolled) .nav-toggle:hover {
    background: rgba(255, 255, 255, .12);
    filter: none;
}
.site-header.is-scrolled .nav-toggle {
    background: var(--navy-500);
    color: #fff;
}

/* 桌機捲動後：主選單收合為漢堡，由側邊展開；操作區改由自身靠右 */
.site-header.is-scrolled .main-nav { display: none; }
.site-header.is-scrolled .nav-toggle { display: grid; }
.site-header.is-scrolled .header-actions { margin-left: auto; }
.site-header.is-scrolled .header-inner {
    width: auto;
    max-width: none;
    margin-inline: 0;
    padding-inline: clamp(1.25rem, 2.5vw, 2.5rem);
}
.site-header.is-scrolled .nav-toggle { width: 80px; }

/* 桌機捲動後：header-inner 仍保留左右留白，僅漢堡按鈕貼齊右緣 */
@media (min-width: 1025px) {
    .site-header.is-scrolled .header-inner {
        padding-right: clamp(1rem, 2vw, 1.75rem);
    }
}

/* ------------------------------------------------------------------ */
/* 側邊展開選單（寬版雙欄，參考專業會計師事務所側欄架構）                 */
/* ------------------------------------------------------------------ */
.mobile-nav {
    position: fixed; inset: 0;
    z-index: 1100;
    visibility: hidden;
    pointer-events: none;
}
.mobile-nav__scrim {
    position: absolute; inset: 0;
    background: rgba(4, 35, 63, .45);
    opacity: 0; transition: opacity .45s var(--ease);
}
.mobile-nav__panel {
    position: absolute; top: 0; right: 0; bottom: 0;
    width: min(58vw, 760px);
    background: #fff;
    padding: 5.5rem clamp(1.8rem, 4vw, 3.5rem) 2.5rem;
    transform: translateX(100%);
    transition: transform .5s var(--ease);
    display: flex;
    flex-direction: column;
    box-shadow: -24px 0 60px rgba(4, 35, 63, .18);
    overflow-y: auto;
}
.mobile-nav.is-open { visibility: visible; pointer-events: auto; }
.mobile-nav.is-open .mobile-nav__scrim { opacity: 1; }
.mobile-nav.is-open .mobile-nav__panel { transform: translateX(0); }

/* 關閉鈕：貼齊右上角，與漢堡色塊同規格 */
.mobile-nav__close {
    position: absolute;
    top: 0; right: 0;
    width: 80px; height: 80px;
    display: grid; place-items: center;
    background: var(--navy-500);
    color: #fff;
    border-radius: 0;
    z-index: 2;
    transition: background .3s var(--ease);
}
.mobile-nav__close:hover { background: var(--navy-600); }
.mobile-nav__close .ico { stroke-width: 2.2; }

/* 搜尋列 */
.side-search {
    display: flex;
    align-items: center;
    gap: .6rem;
    border-bottom: 1px solid var(--line);
    padding: .4rem 0 .9rem;
    margin: 0 5.5rem 2.4rem 0;
}
.side-search input {
    flex: 1;
    border: 0; outline: none;
    background: transparent;
    font-size: 1rem;
    color: var(--ink);
    padding: .4rem 0;
}
.side-search input::placeholder { color: var(--muted); }
.side-search button {
    color: var(--navy-800);
    display: grid; place-items: center;
    padding: .3rem;
    transition: color .3s;
}
.side-search button:hover { color: var(--navy-500); }

/* 雙欄導覽 */
.side-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(2rem, 4vw, 4rem);
    flex: 1;
    align-content: start;
}
.side-nav__col { display: grid; gap: 2.2rem; align-content: start; }
.side-nav__block { display: grid; gap: .7rem; }

.side-nav__head {
    display: grid; gap: .25rem;
    color: var(--ink);
    transition: color .3s var(--ease);
}
.side-nav__head:hover { color: var(--navy-500); }
.side-nav__en {
    font-family: var(--font-en);
    font-size: clamp(1.35rem, 2.4vw, 1.85rem);
    font-weight: 800;
    letter-spacing: .04em;
    line-height: 1.15;
    text-transform: uppercase;
    color: inherit;
}
.side-nav__zh {
    font-size: .92rem;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: .06em;
}
.side-nav__head:hover .side-nav__zh { color: var(--navy-500); }

.side-nav__subs {
    display: grid;
    gap: .45rem;
    padding-left: .1rem;
    margin-top: .15rem;
}
.side-nav__subs a {
    display: block;
    font-size: .95rem;
    color: var(--ink-soft);
    padding: .15rem 0 .15rem 0;
    border: 0;
    position: relative;
    padding-left: 1rem;
}
.side-nav__subs a::before {
    content: "–";
    position: absolute; left: 0; top: .15rem;
    color: var(--navy-500);
    font-weight: 700;
}
.side-nav__subs a:hover { color: var(--navy-500); padding-left: 1.15rem; }

.side-nav__foot {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2.8rem;
    padding-top: 1.6rem;
    border-top: 1px solid var(--line);
}
.side-nav__social { display: flex; gap: .8rem; }
.side-nav__social a {
    width: 40px; height: 40px;
    display: grid; place-items: center;
    color: var(--navy-800);
    border: 1px solid var(--line);
    border-radius: 50%;
    transition: background .3s, color .3s, border-color .3s;
}
.side-nav__social a:hover {
    background: var(--navy-500);
    border-color: var(--navy-500);
    color: #fff;
}

/* 選單開啟時隱藏原漢堡鈕，避免與關閉鈕重疊 */
body.is-nav-open .nav-toggle { visibility: hidden; pointer-events: none; }
body.is-nav-open .site-header { pointer-events: none; }
body.is-nav-open .site-header .brand,
body.is-nav-open .site-header .header-actions { pointer-events: auto; }

/* ------------------------------------------------------------------ */
/* Footer                                                              */
/* ------------------------------------------------------------------ */
.site-footer {
    background: var(--navy-900);
    color: rgba(255, 255, 255, .72);
    padding-top: 4.5rem;
}
.footer-top {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1.3fr;
    gap: 3rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid rgba(255, 255, 255, .12);
}
.footer-brand__logo img { height: 52px; width: auto; }
.footer-brand p { margin-top: 1.2rem; max-width: 34ch; font-size: .95rem; }
.footer-col h4 {
    color: #fff; font-size: 1rem; letter-spacing: .06em;
    margin-bottom: 1.2rem;
}
.footer-col ul { display: grid; gap: .7rem; }
.footer-col a { color: rgba(255,255,255,.72); font-size: .95rem; }
.footer-col a:hover { color: var(--gold-400); padding-left: 4px; }
.footer-contact li { display: flex; gap: .7rem; margin-bottom: .9rem; font-size: .95rem; }
.footer-contact .ico { color: var(--gold-400); flex-shrink: 0; margin-top: 3px; }

.footer-bottom {
    display: flex; align-items: center; justify-content: space-between;
    flex-wrap: wrap; gap: 1rem;
    padding-block: 1.6rem;
    font-size: .85rem;
    color: rgba(255,255,255,.5);
}
.footer-social { display: flex; gap: .7rem; }
.footer-social a {
    width: 40px; height: 40px; border-radius: 50%;
    display: grid; place-items: center;
    background: rgba(255,255,255,.08);
    color: #fff;
}
.footer-social a:hover { background: var(--gold-500); color: var(--navy-900); }

/* Back to top */
.to-top {
    position: fixed; right: 1.5rem; bottom: 1.5rem;
    z-index: 900;
    width: 50px; height: 50px; border-radius: 50%;
    background: var(--navy-800); color: #fff;
    display: grid; place-items: center;
    box-shadow: var(--shadow-md);
    opacity: 0; transform: translateY(20px);
    pointer-events: none;
    transition: opacity .4s var(--ease), transform .4s var(--ease), background .3s;
}
.to-top.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.to-top:hover { background: var(--gold-500); color: var(--navy-900); }

/* ------------------------------------------------------------------ */
/* RWD                                                                 */
/* ------------------------------------------------------------------ */
@media (max-width: 1024px) {
    .main-nav { display: none; }
    .nav-toggle { display: grid; width: 80px; }
    .header-actions { display: none; }
    .header-inner {
        width: auto;
        max-width: none;
        padding-inline: clamp(1.25rem, 4vw, 1.75rem);
        margin-inline: 0;
    }
    .mobile-nav__panel { width: min(92vw, 560px); }
    .mobile-nav__close { width: 80px; height: 80px; }
    .footer-top { grid-template-columns: 1fr 1fr; }
    .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
    .site-header { height: 72px; }
    .site-header.is-scrolled { height: 68px; }
    .brand__logo { height: 44px; }
    .site-header.is-scrolled .brand__logo { height: 40px; }
    .nav-toggle { width: 68px; }
    .mobile-nav__close { width: 68px; height: 68px; }
    .mobile-nav__panel {
        width: 100%;
        padding: 5rem 1.4rem 2rem;
    }
    .side-search { margin-right: 4.5rem; }
    .side-nav { grid-template-columns: 1fr; gap: 1.8rem; }
    .side-nav__col { gap: 1.6rem; }
    .side-nav__en { font-size: 1.45rem; }
    .brand__zh { font-size: .98rem; }
    .footer-top { grid-template-columns: 1fr; gap: 2rem; }
    .footer-brand {
        display: flex;
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    .footer-brand__logo { justify-content: center; }
    .footer-brand p {
        max-width: none;
        width: 100%;
    }
    .footer-col--nav ul {
        grid-template-columns: repeat(3, 1fr);
        gap: .7rem .5rem;
    }
    .footer-col--nav a { font-size: .85rem; }
}