/* HEADER */
.site-header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
}

.header-inner {
    max-width: 1100px;
    margin: auto;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* LEFT */
.header-left {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo {
    display: none;
    width: 42px;
    height: 42px;
}

/* Light mode */
[data-theme="light"] .logo-light {
    display: block;
}

/* Dark mode */
[data-theme="dark"] .logo-dark {
    display: block;
}

.brand-name {
    font-weight: 600;
    font-size: 16pt;
}

/* CENTER NAV */
.header-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 2rem;
}

.nav-link {
    position: relative;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -4px;
    width: 0%;
    height: 2px;
    background: var(--text-color);
    transition: width 0.25s ease;
}

.nav-link:hover {
    color: var(--text-color);
}

.nav-link:hover::after {
    width: 100%;
}

/* RIGHT */
.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* LOGIN */
.login-btn {
    padding: 0.4rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-color);
    text-decoration: none;
}

.login-btn:hover {
    background: var(--highlight-bg);
}

/* DROPDOWN MENU */

.nav-dropdown {
    position: relative;
}

/* Trigger */
.dropdown-trigger {
    cursor: pointer;
}

/* Dropdown box */
.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);

    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;

    min-width: 180px;
    padding: 0.5rem 0;

    display: none;
    z-index: 1000;

    /* modern feel */
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
}

.dropdown-menu {
    opacity: 0;
    transform: translate(-50%, 10px);
    transition: all 0.2s ease;
}

.nav-dropdown:hover .dropdown-menu {
    display: block;
    opacity: 1;
    transform: translate(-50%, 0);
}

/* Show on hover */
.nav-dropdown:hover .dropdown-menu {
    display: block;
}

/* Items */
.dropdown-item {
    display: block;
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
    color: var(--text-color);
    text-decoration: none;
    transition: background 0.2s;
}

/* Hover effect */
.dropdown-item:hover {
    background: var(--highlight-bg);
}

/* Dark mode shadow fix */
[data-theme="dark"] .dropdown-menu {
    box-shadow: 0 10px 25px rgba(0,0,0,0.4);
}

.nav-dropdown {
    position: relative;
}

/* CREATE HOVER BRIDGE */
.nav-dropdown::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    height: 10px; /* bridge gap */
}

/* Dropdown */
.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    
    display: none;
}

/* KEEP OPEN WHEN HOVERING ANY PART */
.nav-dropdown:hover .dropdown-menu,
.dropdown-menu:hover {
    display: block;
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    width: 45px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.theme-toggle:hover {
    opacity: 0.8;
}

[data-theme="dark"] .site-header {
    background: #000000;
    border-bottom: 1px solid var(--border-color);
}

.theme-icon {
    font-size: 1.5rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Light bulb - OFF state (light mode) */
[data-theme="light"] .theme-icon::after {
    content: "💡";
    opacity: 0.4;
    filter: grayscale(1) brightness(0.8);
}

/* Light bulb - ON state (dark mode) */
[data-theme="dark"] .theme-icon::after {
    content: "💡";
    filter: brightness(1.8) saturate(1.5);
}