/* ======================================
   UNIFIED NAVIGATION SYSTEM
   Two-tier structure: Submenu (top) + Navbar (bottom)
   ====================================== */

:root {
    --primary-color: #1e293b;
    --primary-hover: #334155;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --success-color: #10b981;
    --background-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --radius: 8px;
    --transition: all 0.2s ease;
}

/* TOP SUBMENU - Tools Navigation */
.top-submenu {
    background: var(--background-color);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 0;
}

.submenu-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
}

.submenu-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    transition: var(--transition);
    font-size: 0.95rem;
}

.submenu-link:hover {
    color: var(--text-primary);
    background: var(--card-bg);
    box-shadow: var(--shadow-sm);
}

.submenu-link.active {
    color: var(--accent-color);
    background: var(--card-bg);
    font-weight: 600;
    box-shadow: var(--shadow-sm);
}

/* MAIN NAVBAR - Logo, Center Content, User Actions */
.main-navbar {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    height: 70px;
}

.navbar-left {
    display: flex;
    align-items: center;
    min-width: max-content;
}

.navbar-left a {
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo-img {
    height: 45px;
    width: auto;
}

.navbar-center {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 2rem;
}

.navbar-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: max-content;
}

/* NAVIGATION BUTTONS */
.nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
    border: 1px solid transparent;
    font-size: 0.9rem;
    white-space: nowrap;
}

.nav-btn:hover {
    color: var(--text-primary);
    background: var(--background-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.nav-btn.primary {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    font-weight: 600;
}

.nav-btn.primary:hover {
    background: var(--accent-hover);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.nav-btn.outline {
    border-color: var(--border-color);
    color: var(--text-primary);
}

.nav-btn.outline:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background: var(--card-bg);
}

.nav-btn.success {
    background: var(--success-color);
    color: white;
    border-color: var(--success-color);
}

/* MOBILE MENU TOGGLE */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius);
    transition: var(--transition);
}

.mobile-menu-toggle:hover {
    color: var(--text-primary);
    background: var(--background-color);
}

/* MOBILE STYLES */
@media (max-width: 768px) {
    .submenu-container {
        padding: 0 1rem;
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: flex-start;
    }
    
    .navbar-container {
        padding: 0 1rem;
    }
    
    .navbar-center {
        padding: 0 1rem;
    }
    
    .logo-img {
        height: 40px;
    }
    
    .nav-btn {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }
    
    .nav-btn span:not(.material-icons-round) {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    /* Hide submenu on mobile, show via toggle */
    .top-submenu {
        display: none;
    }
    
    .top-submenu.mobile-open {
        display: block;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--card-bg);
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
        z-index: 999;
    }
    
    .top-submenu.mobile-open .submenu-container {
        flex-direction: column;
        padding: 1rem;
        gap: 0.5rem;
    }
    
    .top-submenu.mobile-open .submenu-link {
        width: 100%;
        text-align: center;
        padding: 1rem;
        background: var(--background-color);
        border: 1px solid var(--border-color);
    }
}

@media (max-width: 480px) {
    .navbar-container {
        padding: 0 0.75rem;
    }
    
    .submenu-container {
        padding: 0 0.75rem;
    }
}

/* LOADING STATE */
.nav-loading {
    opacity: 0.7;
    pointer-events: none;
}

.nav-loading .nav-btn {
    background: var(--background-color);
    color: var(--text-muted);
    border-color: var(--border-color);
}