/* Shared header, navigation and footer for jianwdong.com.
   Included on every page through _includes/site-head.html.
   Page-specific styles stay in each page's own <style> block. */

/* Theme. The script in site-head.html sets data-theme="light" or "dark" on <html>
   before the page paints (saved choice, else the system setting). The dark values
   override each page's own :root colors because :root[data-theme] is more specific. */
:root {
    --surface: #fff;
    --card-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --primary-color: #e2e8f0;
    --secondary-color: #b6c0cc;
    --accent-color: #63b3ed;
    --background-color: #11161d;
    --surface: #1a212b;
    --card-shadow: 0 0 0 1px #262f3b;
    --muted: #8d99a8;
    --grid: #2d3743;
    --crit: #f07a7a;
    --good: #4cc771;
    --info-bg: #132739;
    --info-border: #234766;
    --info-ink: #90cdf4;
    --warn-bg: #2a2115;
    --warn-border: #634a20;
    --warn-ink: #f4c27f;
    --err-bg: #2c1618;
    --err-border: #6a2c31;
    --err-ink: #feb2b2;
    --series-1: #3987e5;
    --series-2: #d95926;
    --violent: #3987e5;
    --property: #d95926;
}

.site-header {
    position: relative;
    z-index: 1000;
    background-color: var(--surface);
    padding: 2rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.site-nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
}

.site-brand {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--primary-color, #2d3748);
    text-decoration: none;
    white-space: nowrap;
    transition: color 0.3s ease;
}

.site-brand:hover {
    color: var(--accent-color, #4299e1);
}

.site-menu,
.dropdown-menu {
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link,
.dropdown-toggle {
    font: inherit;
    color: var(--secondary-color, #4a5568);
    text-decoration: none;
    transition: color 0.3s ease;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
    padding: 0;
    background: none;
    border: 0;
    cursor: pointer;
}

.nav-link:hover,
.dropdown-toggle:hover,
.dropdown.is-open > .dropdown-toggle {
    color: var(--accent-color, #4299e1);
}

.chevron {
    flex: none;
    transition: transform 0.3s ease;
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 220px;
    background-color: var(--surface);
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    z-index: 1000;
}

.dropdown-item {
    display: block;
    padding: 1rem 1.5rem;
    color: var(--secondary-color, #4a5568);
    text-decoration: none;
    white-space: nowrap;
    transition: background-color 0.2s ease;
}

.dropdown-item:hover {
    background-color: var(--background-color, #f7fafc);
    color: var(--accent-color, #4299e1);
}

/* Open states: tap/click (JS), hover on mouse devices, keyboard focus without JS */
.dropdown.is-open > .dropdown-menu,
html:not(.js) .dropdown:focus-within > .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown.is-open > .dropdown-toggle .chevron,
html:not(.js) .dropdown:focus-within > .dropdown-toggle .chevron {
    transform: rotate(180deg);
}

@media (hover: hover) and (min-width: 1041px) {
    .dropdown:hover > .dropdown-menu {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .dropdown:hover > .dropdown-toggle {
        color: var(--accent-color, #4299e1);
    }

    .dropdown:hover > .dropdown-toggle .chevron {
        transform: rotate(180deg);
    }
}

.site-brand:focus-visible,
.nav-link:focus-visible,
.dropdown-toggle:focus-visible,
.nav-toggle:focus-visible {
    outline: 2px solid var(--accent-color, #4299e1);
    outline-offset: 4px;
    border-radius: 4px;
}

.dropdown-item:focus-visible {
    outline: 2px solid var(--accent-color, #4299e1);
    outline-offset: -2px;
}

/* Hamburger button, shown on phones only */
.nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    margin: -8px -10px -8px 0;
    padding: 0;
    color: var(--primary-color, #2d3748);
    background: none;
    border: 0;
    border-radius: 8px;
    cursor: pointer;
}

.nav-toggle-icon,
.nav-toggle-icon::before,
.nav-toggle-icon::after {
    display: block;
    width: 22px;
    height: 2px;
    background-color: currentColor;
    border-radius: 2px;
    transition: transform 0.2s ease, background-color 0.2s ease;
}

.nav-toggle-icon {
    position: relative;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
    content: "";
    position: absolute;
    left: 0;
}

.nav-toggle-icon::before { top: -7px; }
.nav-toggle-icon::after { top: 7px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
    background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
    transform: translateY(-7px) rotate(-45deg);
}

/* Theme toggle */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: none;
    width: 40px;
    height: 40px;
    margin: -8px -8px -8px 0;
    padding: 0;
    color: var(--secondary-color, #4a5568);
    background: none;
    border: 0;
    border-radius: 8px;
    cursor: pointer;
    transition: color 0.3s ease;
}

.theme-toggle:hover {
    color: var(--accent-color, #4299e1);
}

.theme-toggle:focus-visible {
    outline: 2px solid var(--accent-color, #4299e1);
    outline-offset: 2px;
}

.theme-toggle svg {
    display: block;
}

.theme-toggle .icon-sun,
:root[data-theme="dark"] .theme-toggle .icon-moon {
    display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-sun {
    display: block;
}

/* The toggle needs JavaScript to work */
html:not(.js) .theme-toggle {
    display: none;
}

:root[data-theme="dark"] .site-header {
    box-shadow: 0 1px 0 #262f3b, 0 8px 20px rgba(0, 0, 0, 0.35);
}

@media (min-width: 1041px) {
    :root[data-theme="dark"] .dropdown-menu {
        box-shadow: 0 0 0 1px #2d3743, 0 8px 20px rgba(0, 0, 0, 0.45);
    }
}

.site-footer {
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
    background-color: var(--surface);
    color: var(--secondary-color, #4a5568);
}

.site-footer p {
    margin: 0;
}

/* Narrow desktops: tighten spacing so all menus fit on one row */
@media (min-width: 1041px) and (max-width: 1120px) {
    .site-header {
        padding: 2rem 1.5rem;
    }

    .site-menu {
        gap: 1.25rem;
    }
}

/* Phones and tablets (up to 1040px, where the menus stop fitting on one row):
   one-row header, menu collapses behind the hamburger,
   dropdowns become expandable sections inside it */
@media (max-width: 1040px) {
    .site-header {
        padding: 1rem;
    }

    .site-nav {
        flex-wrap: wrap;
        gap: 0;
    }

    .js .nav-toggle {
        display: inline-flex;
        order: 2;
    }

    .theme-toggle {
        order: 1;
        margin: -8px 4px -8px auto;
    }

    .site-menu {
        order: 3;
    }

    .site-menu {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        margin-top: 0.5rem;
    }

    .js .site-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        margin-top: 0;
        padding: 0.25rem 1rem 0.75rem;
        background-color: var(--surface);
        border-top: 1px solid var(--grid, #e2e8f0);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.08);
        max-height: calc(100vh - 4.5rem);
        overflow-y: auto;
    }

    .js .site-menu.is-open {
        display: flex;
    }

    .site-menu > li + li {
        border-top: 1px solid var(--grid, #e2e8f0);
    }

    .nav-link,
    .dropdown-toggle {
        display: flex;
        width: 100%;
        justify-content: space-between;
        align-items: center;
        padding: 0.85rem 0.25rem;
        font-size: 1.05rem;
        text-align: left;
    }

    .dropdown-menu {
        position: static;
        display: none;
        min-width: 0;
        padding: 0 0 0.5rem 0.5rem;
        border-radius: 0;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        transition: none;
    }

    .dropdown.is-open > .dropdown-menu,
    html:not(.js) .dropdown-menu {
        display: block;
    }

    .dropdown-item {
        padding: 0.65rem 0.75rem;
        border-radius: 6px;
        white-space: normal;
    }
}