/* ══════════════════════════════════════════════════════
   Navigation — Fixed navbar with scroll state transition
   ══════════════════════════════════════════════════════ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: var(--z-fixed);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    height: var(--header-height);
    display: flex;
    align-items: center;
    /* FIX M-1: Pre-promote to own compositing layer so scroll
       state transitions don't trigger full-page repaint */
    will-change: background-color, box-shadow;
}

.navbar-transparent {
    background: transparent;
}

.navbar-scrolled {
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: var(--container-width);
    padding: 0 var(--container-padding);
    margin: 0 auto;
}

/* ── Brand ─────────────────────────────────────────── */

.navbar-brand {
    font-family: 'Cabin', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--light-text);
    transition: color 0.3s ease;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex-shrink: 1;
    min-width: 0;
}

.navbar-brand img {
    height: 40px;
    margin-right: 10px;
    flex-shrink: 0;
}

.navbar-scrolled .navbar-brand {
    color: var(--dark-color);
}

/* ── Desktop nav links ─────────────────────────────── */

.navbar-nav {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    align-items: center;
}

.nav-item {
    position: relative;
    margin: 0 1rem;
}

.nav-link {
    font-family: 'Lato', sans-serif;
    font-size: 1rem;
    font-weight: 600;
    color: var(--light-text);
    padding: 8px 0;
    display: block;
    position: relative;
    transition: color 0.3s ease;
    text-decoration: none;
    white-space: nowrap;
}

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

/* ── Dropdown (desktop) ────────────────────────────── */

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 220px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    padding: 10px 0;
    z-index: 100;
    margin-top: 10px;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    padding: 10px 20px;
    color: var(--text-color);
    font-size: 0.95rem;
    transition: background-color 0.2s ease, color 0.2s ease;
    font-weight: 500;
    text-decoration: none;
}

.dropdown-item:hover {
    background-color: rgba(10, 126, 140, 0.08);
    color: var(--primary-color);
}

/* ── Hamburger toggle button ───────────────────────── */

.navbar-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    /* FIX H-1: Increased opacity 0.25→0.4 + added border for
       sufficient contrast on both dark hero/auth backgrounds
       and light scrolled navbar backgrounds */
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.2);
    cursor: pointer;
    padding: 8px;
    position: relative;
    z-index: 1001;
    width: 44px;
    height: 44px;
    border-radius: var(--border-radius-sm);
    flex-shrink: 0;
    margin-left: auto;
    -webkit-tap-highlight-color: transparent;
}

.navbar-toggle:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Scrolled state: lighter background for dark-on-white bars */
.navbar-scrolled .navbar-toggle {
    background: rgba(0, 0, 0, 0.06);
    border-color: rgba(0, 0, 0, 0.1);
}

/* ── Hamburger icon — 3 bars via element + pseudo ──── */

.hamburger-icon {
    width: 22px;
    height: 3px;
    background-color: #FFFFFF;
    position: relative;
    display: block;
    border-radius: 2px;
    transition: background-color 0.3s ease;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
}

.hamburger-icon::before,
.hamburger-icon::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: #FFFFFF;
    border-radius: inherit;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
    left: 0;
    transition: top 0.3s ease, bottom 0.3s ease, transform 0.3s ease, background-color 0.3s ease;
}

.hamburger-icon::before {
    top: -7px;
}

.hamburger-icon::after {
    bottom: -7px;
}

/* Active state: middle bar hidden, top/bottom rotate to X
   FIX C-2: Explicit background-color on ::before/::after —
   previous rule used `inherit` which inherited `transparent`
   from the parent, making the X close icon invisible. */
.navbar-toggle.active .hamburger-icon {
    background-color: transparent;
    box-shadow: none;
}

.navbar-toggle.active .hamburger-icon::before {
    top: 0;
    transform: rotate(45deg);
    background-color: #FFFFFF;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
}

.navbar-toggle.active .hamburger-icon::after {
    bottom: 0;
    transform: rotate(-45deg);
    background-color: #FFFFFF;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
}

/* Scrolled state: dark bars for light background */
.navbar-scrolled .hamburger-icon {
    background-color: #333333;
    box-shadow: none;
}

.navbar-scrolled .hamburger-icon::before,
.navbar-scrolled .hamburger-icon::after {
    background-color: #333333;
    box-shadow: none;
}

/* Scrolled + active: dark X on light background */
.navbar-scrolled .navbar-toggle.active .hamburger-icon {
    background-color: transparent;
}

.navbar-scrolled .navbar-toggle.active .hamburger-icon::before,
.navbar-scrolled .navbar-toggle.active .hamburger-icon::after {
    background-color: #333333;
    box-shadow: none;
}

/* ── Scroll-reveal animation classes ─────────────────
   Used by IntersectionObserver in menubar.html script.
   Replaces lax.js dependency with native CSS transitions.
   ──────────────────────────────────────────────────── */

.section {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.section-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ══════════════════════════════════════════════════════
   Responsive — Tablet and below (≤992px)
   ══════════════════════════════════════════════════════ */

@media (max-width: 992px) {

    .navbar-toggle {
        display: flex;
    }

    .navbar-collapse {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        height: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        overflow: hidden;
        transition: height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: var(--z-modal);
    }

    .navbar-collapse.show {
        height: calc(100vh - var(--header-height));
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }

    .navbar-nav {
        flex-direction: column;
        padding: 20px;
        opacity: 0;
        transform: translateY(-10px);
        transition: opacity 0.3s ease 0.1s, transform 0.3s ease 0.1s;
    }

    .navbar-collapse.show .navbar-nav {
        opacity: 1;
        transform: translateY(0);
    }

    .nav-item {
        margin: 8px 0;
    }

    .nav-link {
        color: var(--text-color);
        font-size: 1.15rem;
        padding: 12px 0;
    }

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

    /* Mobile dropdown — accordion behavior */
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        width: 100%;
        background: transparent;
        box-shadow: none;
        padding: 0 0 0 20px;
        margin-top: 5px;
        display: none;
    }

    .dropdown.open .dropdown-menu {
        display: block;
    }

    .dropdown-item {
        padding: 10px 0;
        color: var(--dark-gray);
    }

    .dropdown-item:hover {
        background: transparent;
        color: var(--primary-color);
    }

    /* Dropdown chevron indicator */
    .dropdown > .nav-link::after {
        content: '\25BE'; /* ▾ */
        position: absolute;
        right: 0;
        top: 50%;
        transform: translateY(-50%);
        width: auto;
        height: auto;
        background: none;
        font-size: 0.8rem;
        transition: transform 0.3s ease;
    }

    .dropdown.open > .nav-link::after {
        transform: translateY(-50%) rotate(180deg);
    }
}

/* ══════════════════════════════════════════════════════
   Responsive — Small phone (≤576px)
   ══════════════════════════════════════════════════════ */

@media (max-width: 576px) {

    .navbar {
        height: 60px;
    }

    .navbar-brand {
        font-size: 1.4rem;
    }

    .navbar-brand img {
        height: 28px;
    }

    .navbar-collapse {
        top: 60px;
    }

    .navbar-collapse.show {
        height: calc(100vh - 60px);
    }

    .navbar-toggle {
        width: 44px;
        height: 44px;
    }

    .hamburger-icon {
        width: 20px;
        height: 2px;
    }

    .hamburger-icon::before {
        top: -6px;
    }

    .hamburger-icon::after {
        bottom: -6px;
    }
}