/* Header */
.header {
    position: relative;
    background: url("/_newSite/assets/images/back2.png") center/cover no-repeat;
    min-height: 100px;
    z-index: 1000;
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
    gap: 16px;
}

.header__nav-container {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* Brand */
.header__brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    letter-spacing: 0.02em;
    flex-shrink: 0; /* 防止LOGO被壓縮 */
}

.header__logo {
    width: clamp(350px, 45vw, 600px);
    height: auto;
    max-width: 100%;
    display: block;
}

/* Social Media Links */
.header__social {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
}

.header__social-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 8px;
    border-radius: 6px;
    transition: background-color 0.25s ease;
    text-decoration: none;
    color: inherit;
    font-size: clamp(13px, 1.1vw, 15px);
    white-space: nowrap;
}

.header__social-link:hover {
    background-color: rgba(180, 180, 180, 0.3);
}

.header__social-link img {
    width: clamp(24px, 2.5vw, 28px);
    height: auto;
}

/* Navigation */
.header__nav {
    display: flex;
    gap: 8px;
    align-items: center;
}

.nav-link {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-1);
    position: relative;
    padding: 4px 6px;
    transition: background-color 0.25s;
}

.nav-link:hover {
    background-color: rgba(180, 180, 180, 0.5);
}

.nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -6px;
    height: 2px;
    background: var(--text-1);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.25s;
}

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

/* Submenu */
.nav-item--has-submenu {
    position: relative;
}

.nav-submenu {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--neutral-0);
    list-style: none;
    padding: 8px 0;
    margin: 0;
    border: 1px solid var(--neutral-2);
    border-radius: 10px;
    box-shadow: var(--shadow-1);
    opacity: 0;
    transform: translateY(6px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 999;
    min-width: 200px;
}

.nav-submenu li a {
    display: block;
    padding: 6px 16px;
    white-space: nowrap;
    color: var(--text-1);
    font-size: clamp(14px, 1.2vw, 16px);
    transition: background-color 0.2s;
}

.nav-submenu li a:hover {
    background: var(--neutral-1);
}

.nav-item--has-submenu:hover .nav-submenu {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

/* Third level submenu (nested) */
.nav-submenu .nav-item--has-submenu {
    position: relative;
}

.nav-submenu .nav-item--has-submenu .nav-submenu {
    position: absolute;
    top: 0;
    right: 100%; /* 向左顯示以避免重疊 */
    left: auto;
    margin-right: 0px; /* 增加一些間距 */
    opacity: 0;
    transform: translateX(-6px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.nav-submenu .nav-item--has-submenu:hover .nav-submenu {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
}

/* Mobile Menu Button */
.header__menu-btn {
    display: none;
    border: 1px solid var(--neutral-2);
    padding: 8px 10px;
    border-radius: 8px;
    background: var(--neutral-0);
    cursor: pointer;
}

.menu-icon {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-1);
    position: relative;
    transition: background 0.3s;
}

.menu-icon::before,
.menu-icon::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 2px;
    background: var(--text-1);
    transition: transform 0.3s;
}

.menu-icon::before {
    top: -6px;
}

.menu-icon::after {
    top: 6px;
}

.header__menu-btn[aria-expanded="true"] .menu-icon {
    background: transparent;
}

.header__menu-btn[aria-expanded="true"] .menu-icon::before {
    transform: rotate(45deg) translate(0, 6px);
}

.header__menu-btn[aria-expanded="true"] .menu-icon::after {
    transform: rotate(-45deg) translate(0, -6px);
}

/* Sticky Header */
.header.is-sticky {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    right: 0;
    z-index: 2000;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.header.is-sticky .header__inner {
    padding: 8px 0;
    transition: padding 0.2s ease;
}

/* Screen Reader Only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Mobile Styles */
@media (max-width: 1024px) {
    .header__nav-container {
        position: relative;
        flex-direction: column;
        align-items: flex-end;
        gap: 8px;
    }

    .header__nav {
        display: none;
        position: absolute;
        right: 0;
        top: 52px;
        background: var(--neutral-0);
        padding: 12px;
        border-radius: 10px;
        box-shadow: var(--shadow-1);
        flex-direction: column;
        gap: 10px;
        align-items: stretch;
    }

    .header__menu-btn {
        display: inline-block;
    }

    .header__nav.is-open {
        display: flex;
    }

    .header__social {
        order: -1;
        align-items: center;
        gap: 8px;
    }

    .header__social-link {
        font-size: clamp(12px, 3vw, 14px);
    }

    .header__social-link img {
        width: clamp(20px, 4vw, 24px);
    }

    .nav-item--has-submenu {
        display: flex;
        flex-direction: column;
        gap: 6px;
    }

    .nav-submenu {
        position: static;
        opacity: 1;
        transform: none;
        pointer-events: auto;
        border: none;
        box-shadow: none;
        padding: 0 0 6px 10px;
        margin-left: 10px;
    }

    .nav-submenu .nav-item--has-submenu {
        margin-left: 0;
    }

    .nav-submenu .nav-item--has-submenu .nav-submenu {
        position: static;
        margin-left: 16px;
        padding-left: 0;
        border-left: 2px solid var(--neutral-2);
    }
}

/* Medium Screens - Logo sizing similar to footer */
@media (max-width: 960px) {
    .header__logo {
        width: clamp(250px, 60vw, 350px);
    }
}

/* Tablet and Medium Screens */
@media (max-width: 1200px) and (min-width: 641px) {
    .nav-link {
        font-size: clamp(17px, 1.8vw, 19px);
    }

    .nav-submenu li a {
        font-size: clamp(14px, 1.4vw, 15px);
    }
}

@media (max-width: 640px) {
    .header__logo {
        width: clamp(200px, 70vw, 280px);
    }

    .nav-link {
        font-size: clamp(16px, 4vw, 18px);
    }

    .header__social {
        flex-direction: row;
        gap: 6px;
    }

    .header__social-link {
        font-size: clamp(11px, 3vw, 13px);
        gap: 6px;
        padding: 3px 6px;
    }

    .header__social-link img {
        width: 18px;
        height: auto;
    }
}