/* ============================================
   Header / Navbar Module
   ============================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-nav);
    padding: var(--space-3) 0;
    transition: all var(--transition-base);
    background: rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

[data-theme="light"] .header {
    background: rgba(255, 255, 255, 0.65);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.header.scrolled {
    padding: var(--space-2) 0;
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.15);
}

[data-theme="light"] .header.scrolled {
    background: rgba(255, 255, 255, 0.85);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-8);
}

/* --- Logo --- */
.header__logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--text-primary);
    font-weight: var(--weight-bold);
    font-size: var(--text-xl);
    text-decoration: none;
    flex-shrink: 0;
}

.header__logo:hover { color: var(--text-primary); }

.header__logo-img {
    height: 36px;
    width: auto;
    transition: transform var(--transition-base);
}

.header__logo:hover .header__logo-img {
    transform: rotate(-5deg) scale(1.08);
}

.header__logo-text {
    font-weight: var(--weight-extrabold);
    letter-spacing: -0.02em;
}

/* --- Desktop Nav --- */
.header__nav {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.header__nav-link {
    display: block;
    padding: var(--space-2) var(--space-4);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    font-weight: var(--weight-medium);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    text-decoration: none;
    white-space: nowrap;
}

.header__nav-link:hover,
.header__nav-link.active {
    color: var(--text-primary);
    background: var(--accent-light);
}

.header__nav-link.active {
    color: var(--accent);
    font-weight: var(--weight-semibold);
}

/* --- Actions --- */
.header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    flex-shrink: 0;
}

/* --- Theme Toggle --- */
.header__theme-toggle {
    position: relative;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    background: none;
    border: none;
    cursor: pointer;
}

.header__theme-toggle:hover {
    background: var(--accent-light);
    color: var(--accent);
}

.icon-sun, .icon-moon {
    position: absolute;
    transition: all var(--transition-base);
}

.icon-sun { opacity: 0; transform: rotate(90deg) scale(0.5); }
.icon-moon { opacity: 1; transform: rotate(0deg) scale(1); }

[data-theme="dark"] .icon-sun { opacity: 1; transform: rotate(0deg) scale(1); }
[data-theme="dark"] .icon-moon { opacity: 0; transform: rotate(-90deg) scale(0.5); }

/* --- Hamburger --- */
.header__hamburger {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    padding: 10px;
    flex-shrink: 0;
    transition: all var(--transition-fast);
}

.header__hamburger:hover {
    border-color: var(--accent);
    background: var(--accent-light);
}

.header__hamburger span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-base);
    transform-origin: center;
}

/* ============================================
   Mobile Sidebar
   ============================================ */

/* Overlay */
.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: calc(var(--z-nav) + 10);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.sidebar-overlay.open {
    opacity: 1;
    visibility: visible;
}

/* Sidebar panel */
.sidebar {
    position: fixed;
    top: 10px;
    right: -340px;
    bottom: 10px;
    width: 300px;
    max-width: calc(85vw - 20px);
    z-index: calc(var(--z-nav) + 20);
    display: flex;
    flex-direction: column;
    transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-2xl);
    box-shadow: -8px 0 60px rgba(0, 0, 0, 0.4);
    overflow: hidden;
}

.sidebar.open {
    right: 10px;
}

/* Sidebar header */
.sidebar__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5) var(--space-6);
    border-bottom: 1px solid var(--border);
}

.sidebar__logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--text-primary);
    text-decoration: none;
    font-size: var(--text-lg);
}

.sidebar__logo-img {
    height: 32px;
    width: auto;
}

.sidebar__logo-text {
    font-weight: var(--weight-extrabold);
    letter-spacing: -0.02em;
}

.sidebar__close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: var(--text-lg);
}

.sidebar__close:hover {
    background: rgba(239, 68, 68, 0.1);
    border-color: rgba(239, 68, 68, 0.3);
    color: #ef4444;
}

/* Sidebar nav */
.sidebar__nav {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: var(--space-4) var(--space-4);
    overflow-y: auto;
}

.sidebar__nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    color: var(--text-secondary);
    font-size: var(--text-base);
    font-weight: var(--weight-medium);
    text-decoration: none;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
    margin-bottom: var(--space-1);
}

.sidebar__nav-link:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.sidebar__nav-link.active {
    background: var(--accent-light);
    color: var(--accent);
    font-weight: var(--weight-semibold);
}

/* Sidebar footer */
.sidebar__footer {
    padding: var(--space-5) var(--space-6);
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.sidebar__btn {
    width: 100%;
    text-align: center;
    text-decoration: none;
    padding: var(--space-3) var(--space-4);
}

/* Theme toggle in sidebar */
.sidebar__theme {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--space-3);
    border-top: 1px solid var(--border);
    margin-top: var(--space-1);
}

.sidebar__theme > span {
    font-size: var(--text-sm);
    color: var(--text-muted);
    font-weight: var(--weight-medium);
}

.sidebar__theme-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: var(--text-sm);
    font-family: var(--font-sans);
    transition: all var(--transition-fast);
    position: relative;
}

.sidebar__theme-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.sidebar__theme-btn .icon-sun,
.sidebar__theme-btn .icon-moon {
    position: relative;
}

.sidebar__theme-label {
    font-size: var(--text-xs);
    color: var(--text-muted);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
    .header__hamburger { display: flex; }
    .header__nav { display: none; }
    .header__cta-desktop { display: none; }
}