/**
 * 顶栏导航 — include/header.php
 * 含：桌面 dropdown、移动抽屉、主题切换按钮
 */

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--header-h);
    background: var(--color-nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    overflow: visible;
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-max);
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--space-md);
    gap: var(--space-md);
    overflow: visible;
}

.site-header__logo-svg {
    display: block;
    height: 32px;
    width: auto;
}

/* Logo SVG：文字/分隔线随主题变量变色，BTC126 保持品牌橙 */
.site-header__logo-text {
    fill: var(--color-text);
    font-family: var(--font-body);
}

.site-header__logo-text--main {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.site-header__logo-divider {
    stroke: var(--color-text);
    stroke-width: 1.5;
    opacity: 0.75;
}

.site-header__logo-text--brand {
    fill: var(--color-logo-brand);
    font-family: var(--font-display);
    font-size: 22px;
    font-weight: 700;
    letter-spacing: 0.04em;
}

.site-header__logo-text--sub {
    font-size: 18px;
    font-weight: 500;
}

/* 桌面导航 */
.site-nav {
    display: none;
    align-items: center;
    gap: 2px;
    list-style: none;
    margin: 0;
    padding: 0;
}

@media (min-width: 769px) {
    .site-nav {
        display: flex;
        flex: 1;
        justify-content: center;
    }
}

.site-nav__item {
    position: relative;
}

.site-nav__link {
    display: block;
    padding: 8px 12px;
    color: var(--color-text-muted);
    font-size: 14px;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
}

.site-nav__link:hover,
.site-nav__item.is-open > .site-nav__link,
.site-nav__item.has-dropdown.is-hover > .site-nav__link {
    color: var(--color-text);
    background: var(--color-surface-hover);
}

/* 下拉项右侧小箭头 */
.site-nav__link[data-dropdown]::after {
    content: '';
    display: inline-block;
    width: 0;
    height: 0;
    margin-left: 5px;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 4px solid currentColor;
    vertical-align: middle;
    opacity: 0.6;
    transition: transform var(--transition-fast);
}

.site-nav__item.is-open > .site-nav__link[data-dropdown]::after,
.site-nav__item.has-dropdown.is-hover > .site-nav__link[data-dropdown]::after {
    transform: rotate(180deg);
}

/* Dropdown 面板 */
.site-nav__dropdown {
    position: absolute;
    top: calc(100% + 4px);
    left: 50%;
    transform: translateX(-50%) translateY(-4px);
    min-width: 160px;
    padding: var(--space-xs) 0;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 24px var(--color-shadow);
    list-style: none;
    margin: 0;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
}

.site-nav__item.is-open .site-nav__dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* 桌面端：悬停展开下拉（替代原 Layui 行为） */
@media (min-width: 769px) {
    .site-nav__item.has-dropdown.is-hover .site-nav__dropdown {
        opacity: 1;
        visibility: visible;
        transform: translateX(-50%) translateY(0);
    }
}

.site-nav__dropdown a {
    display: block;
    padding: 8px 16px;
    color: var(--color-text-muted);
    font-size: 13px;
    white-space: nowrap;
}

.site-nav__dropdown a:hover {
    color: var(--color-accent);
    background: var(--color-surface-hover);
}

/* 法币选择器 — include/header.php currency-picker */
.currency-picker {
    position: relative;
}

.currency-picker__toggle {
    display: flex;
    align-items: center;
    gap: 4px;
    height: 36px;
    padding: 0 10px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    font-size: 13px;
    font-family: var(--font-mono, monospace);
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.currency-picker__toggle:hover,
.currency-picker.is-open .currency-picker__toggle {
    color: var(--color-text);
    border-color: var(--color-accent);
}

.currency-picker__chevron {
    display: inline-block;
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 4px solid currentColor;
    opacity: 0.6;
    transition: transform var(--transition-fast);
}

.currency-picker.is-open .currency-picker__chevron {
    transform: rotate(180deg);
}

.currency-picker__menu {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    z-index: 20;
    min-width: 120px;
    margin: 0;
    padding: var(--space-xs) 0;
    list-style: none;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 24px var(--color-shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
}

.currency-picker.is-open .currency-picker__menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.currency-picker__option {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 8px 14px;
    border: none;
    background: none;
    color: var(--color-text-muted);
    font-size: 13px;
    font-family: var(--font-mono, monospace);
    text-align: left;
    cursor: pointer;
}

.currency-picker__option:hover,
.currency-picker__option.is-active {
    color: var(--color-accent);
    background: var(--color-surface-hover);
}

.currency-picker__option span {
    opacity: 0.7;
    font-size: 12px;
}

/* 右侧操作区 */
.site-header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
    overflow: visible;
}

/* 主题切换 */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
}

.theme-toggle__icon--light { display: none; }
[data-theme="light"] .theme-toggle__icon--dark { display: none; }
[data-theme="light"] .theme-toggle__icon--light { display: block; }

/* 汉堡按钮（SVG 图标，与搜索/主题按钮一致，避免空 span 在部分浏览器不渲染） */
.nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-toggle:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
}

@media (min-width: 769px) {
    .nav-toggle {
        display: none;
    }
}

.nav-toggle__icon {
    display: block;
    flex-shrink: 0;
}

.nav-toggle__bar {
    transition: transform var(--transition-fast), opacity var(--transition-fast);
    transform-box: fill-box;
    transform-origin: center;
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(1) {
    transform: translateY(5px) rotate(45deg);
}
.nav-toggle.is-active .nav-toggle__bar:nth-child(2) {
    opacity: 0;
}
.nav-toggle.is-active .nav-toggle__bar:nth-child(3) {
    transform: translateY(-5px) rotate(-45deg);
}

/* 移动抽屉 */
.mobile-nav {
    position: fixed;
    inset: 0;
    z-index: 1100;
    visibility: hidden;
    pointer-events: none;
}

.mobile-nav.is-open {
    visibility: visible;
    pointer-events: auto;
}

.mobile-nav__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.mobile-nav.is-open .mobile-nav__backdrop {
    opacity: 1;
}

.mobile-nav__panel {
    position: absolute;
    top: 0;
    right: 0;
    width: min(300px, 85vw);
    height: 100%;
    background: var(--color-surface);
    border-left: 1px solid var(--color-border);
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    padding: var(--space-lg) var(--space-md);
}

.mobile-nav.is-open .mobile-nav__panel {
    transform: translateX(0);
}

.mobile-nav__group {
    margin-bottom: var(--space-md);
}

.mobile-nav__label {
    display: block;
    padding: var(--space-sm) 0;
    color: var(--color-accent);
    font-family: var(--font-display);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

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

.mobile-nav__links a {
    display: block;
    padding: 10px 0;
    color: var(--color-text);
    font-size: 15px;
    border-bottom: 1px solid var(--color-border);
}

.mobile-nav__links a:hover {
    color: var(--color-accent);
}