/**
 * Header & Navigation Components
 * Extracted from profile.html and standardized across platform
 */

/* ===== HEADER ===== */
header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-primary);
    padding: 0.75rem 0;
    margin-bottom: 2rem;
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

/* Header container - override page-specific .container styles */
header .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.logo {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: var(--weight-bold);
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-base);
    flex-shrink: 0;
}

.logo:hover {
    color: var(--accent-primary);
}

/* ===== DESKTOP NAVIGATION ===== */
nav {
    display: flex;
    gap: 2rem;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

nav a {
    font-family: var(--font-primary);
    font-size: 0.95rem;
    font-weight: var(--weight-medium);
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-base);
}

nav a:hover {
    color: var(--accent-primary);
}

nav a.active {
    color: var(--accent-primary);
    font-weight: var(--weight-semibold);
}

/* ===== MOBILE MENU BUTTON ===== */
.menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    line-height: 1;
    transition: color var(--transition-base);
}

.menu-btn:hover {
    color: var(--accent-primary);
}

/* ===== MOBILE MENU DROPDOWN ===== */
.mobile-menu {
    display: none;
    position: absolute;
    top: 100%;
    right: 20px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-md);
    margin-top: 0.5rem;
    min-width: 180px;
    box-shadow: var(--shadow-lg);
    z-index: var(--z-dropdown);
}

.mobile-menu.active {
    display: block;
}

.mobile-menu a {
    display: block;
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-family: var(--font-primary);
    font-size: 0.95rem;
    font-weight: var(--weight-medium);
    transition: background-color var(--transition-fast), color var(--transition-fast);
    border-bottom: 1px solid var(--border-primary);
}

.mobile-menu a:last-child {
    border-bottom: none;
}

.mobile-menu a:hover {
    background-color: var(--bg-tertiary);
    color: var(--accent-primary);
}

.mobile-menu a.active {
    color: var(--accent-primary);
    font-weight: var(--weight-semibold);
    background-color: var(--bg-tertiary);
}

/* ===== RESPONSIVE NAVIGATION ===== */
@media (max-width: 768px) {
    nav {
        display: none;
    }

    .menu-btn {
        display: block;
    }

    .logo {
        font-size: 1.5rem;
    }

    header {
        padding: 1rem 0;
    }

    .user-session-area {
        display: none;
    }
}

/* ===== THEME TOGGLE BUTTON ===== */
/* #8: Compact sun/moon toggle in header */
.theme-toggle-btn {
    background: none;
    border: 1px solid var(--border-primary);
    color: var(--text-secondary);
    font-size: 1rem;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition-base), border-color var(--transition-base), background-color var(--transition-base);
    flex-shrink: 0;
    margin-left: auto; /* pushes toggle + user-area + menu-btn flush to right edge */
}

.theme-toggle-btn:hover {
    color: var(--accent-primary);
    border-color: var(--accent-primary);
    background-color: var(--bg-tertiary);
}

@media (max-width: 768px) {
    .theme-toggle-btn {
        display: none;
    }
}