/* ── Header Styles ── */

.site-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: var(--z-header);
    height: var(--header-height);
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--color-border);
    transition: border-color var(--transition-base);
}
.site-header::before {
    content: '';
    position: absolute; inset: 0; z-index: -1;
    background: rgba(10, 14, 18, 0.45);
    backdrop-filter: blur(24px) saturate(200%);
    -webkit-backdrop-filter: blur(24px) saturate(200%);
    transition: background var(--transition-base);
}
:root[data-theme="light"] .site-header::before {
    background: rgba(242, 244, 247, 0.35);
}
.site-header.is-scrolled::before { background: rgba(10, 14, 18, 0.65); }
:root[data-theme="light"] .site-header.is-scrolled::before { background: rgba(242, 244, 247, 0.55); }

.header__container {
    width: 100%; max-width: var(--container-wide);
    margin: 0 auto; padding: 0 var(--space-6);
    display: flex; align-items: center; justify-content: space-between; gap: var(--space-8);
}

/* Logo */
.header__logo { flex-shrink: 0; display: flex; align-items: center; transition: opacity var(--transition-fast); }
.header__logo:hover { opacity: 0.8; }
.header__logo-light { display: none; }
:root[data-theme="light"] .header__logo-dark { display: none; }
:root[data-theme="light"] .header__logo-light { display: block; }

/* Desktop Nav */
.header__nav { display: flex; align-items: center; gap: var(--space-1); }
.nav-item { position: relative; }
.nav-link {
    display: flex; align-items: center; gap: var(--space-1);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm); font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
    white-space: nowrap;
}
.nav-link:hover, .nav-item.is-open > .nav-link {
    color: var(--color-text-primary); background: rgba(255, 255, 255, 0.04);
}
:root[data-theme="light"] .nav-link:hover,
:root[data-theme="light"] .nav-item.is-open > .nav-link {
    background: rgba(0, 0, 0, 0.04);
}

.nav-chevron { transition: transform var(--transition-fast); }
.nav-item.is-open .nav-chevron,
.mobile-menu__link.is-open .nav-chevron { transform: rotate(180deg); }

/* Dropdown */
.nav-dropdown {
    position: absolute; top: calc(100% + var(--space-2)); left: 0;
    min-width: 540px;
    background: rgba(15, 20, 25, 0.92);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg); padding: var(--space-4);
    opacity: 0; visibility: hidden;
    transform: translateY(8px);
    transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
    box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255, 255, 255, 0.05);
    pointer-events: none;
    max-width: calc(100vw - 32px);
}
:root[data-theme="light"] .nav-dropdown {
    background: rgba(255, 255, 255, 0.96);
    border-color: rgba(0, 0, 0, 0.08);
    box-shadow: var(--shadow-lg);
}
.nav-item.is-open > .nav-dropdown {
    opacity: 1; visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}
.nav-dropdown__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-2); }
.nav-dropdown__item {
    display: flex; flex-direction: column; gap: 2px;
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-md);
    transition: background var(--transition-fast);
}
.nav-dropdown__item:hover { background: rgba(255, 255, 255, 0.06); }
:root[data-theme="light"] .nav-dropdown__item:hover { background: rgba(0, 0, 0, 0.04); }
.nav-dropdown__label { font-size: var(--text-sm); font-weight: var(--font-semibold); color: var(--color-text-primary); display: flex; align-items: center; gap: 6px; }
.nav-dropdown__desc { font-size: var(--text-xs); color: var(--color-text-muted); line-height: 1.4; }
.nav-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }

/* Header CTA */
.header__cta { flex-shrink: 0; }
.header__cta-btn {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 10px 24px;
    font-family: var(--font-body); font-size: var(--text-sm); font-weight: var(--font-semibold);
    color: #fff;
    background: linear-gradient(135deg, #FD6263, #D34447);
    border: 1px solid rgba(253, 98, 99, 0.5);
    border-radius: 50px; cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px rgba(253, 98, 99, 0.35);
    white-space: nowrap;
}
.header__cta-btn:hover { transform: translateY(-1px); box-shadow: 0 0 28px rgba(253, 98, 99, 0.5); filter: brightness(1.1); }

/* Theme Toggle */
.theme-toggle {
    display: flex; align-items: center; justify-content: center;
    width: 36px; height: 36px;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    transition: background var(--transition-fast), color var(--transition-fast);
    cursor: pointer; flex-shrink: 0;
}
.theme-toggle:hover { background: rgba(255,255,255,0.06); color: var(--color-text-primary); }
:root[data-theme="light"] .theme-toggle:hover { background: rgba(0,0,0,0.06); }
.theme-toggle__moon { display: none; }
:root[data-theme="light"] .theme-toggle__sun { display: none; }
:root[data-theme="light"] .theme-toggle__moon { display: block; }

/* Hamburger */
.header__burger {
    display: none; flex-direction: column; justify-content: center; gap: 5px;
    width: 32px; height: 32px; padding: 4px;
    z-index: calc(var(--z-header) + 10);
}
.header__burger span {
    display: block; width: 100%; height: 2px;
    background: var(--color-text-primary); border-radius: 2px;
    transition: transform var(--transition-base), opacity var(--transition-fast);
    transform-origin: center;
}
.header__burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.header__burger.is-open span:nth-child(2) { opacity: 0; }
.header__burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile Menu */
.mobile-menu {
    display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    z-index: calc(var(--z-header) - 1);
    background: rgba(15, 20, 25, 0.98);
    backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
    padding-top: var(--header-height); overflow-y: auto;
    opacity: 0; visibility: hidden;
    transition: opacity var(--transition-base), visibility var(--transition-base);
}
:root[data-theme="light"] .mobile-menu { background: rgba(250, 250, 250, 0.98); }
.mobile-menu.is-open { opacity: 1; visibility: visible; }
.mobile-menu__nav {
    padding: var(--space-8) var(--space-6);
    display: flex; flex-direction: column; gap: var(--space-2);
}
.mobile-menu__item { border-bottom: 1px solid var(--color-border); }
.mobile-menu__link {
    display: flex; align-items: center; justify-content: space-between; width: 100%;
    padding: var(--space-4) 0;
    font-size: var(--text-lg); font-weight: var(--font-medium);
    color: var(--color-text-primary);
    background: none; border: none; text-align: left; cursor: pointer;
}
.mobile-menu__link.is-open { color: var(--color-primary); }
.mobile-menu__submenu { max-height: 0; overflow: hidden; transition: max-height var(--transition-slow); }
.mobile-menu__submenu.is-open { max-height: 500px; }
.mobile-menu__subitem {
    display: block; padding: var(--space-3) var(--space-4);
    font-size: var(--text-base); color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}
.mobile-menu__subitem:hover { color: var(--color-primary); }
.mobile-menu__cta { padding-top: var(--space-8); }

/* Scroll Progress */
.scroll-progress {
    position: fixed; top: 0; left: 0; right: 0;
    height: 3px; z-index: calc(var(--z-header) + 1);
}
.scroll-progress__bar {
    height: 100%; width: 0;
    background: var(--color-primary-gradient);
    transition: width 50ms linear;
}

/* Back to Top */
.back-to-top {
    position: fixed; bottom: var(--space-8); right: var(--space-8);
    width: 44px; height: 44px;
    display: flex; align-items: center; justify-content: center;
    background: var(--color-bg-card); border: 1px solid var(--color-border);
    border-radius: var(--radius-full); color: var(--color-text-primary);
    cursor: pointer; opacity: 0; visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-base);
    z-index: var(--z-above);
}
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--color-bg-card-hover); border-color: var(--color-border-hover); transform: translateY(-2px); }

/* Floating Trigger */
.floating-trigger {
    position: fixed; bottom: var(--space-8); left: var(--space-8);
    z-index: var(--z-above); opacity: 0; visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
}
.floating-trigger.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.floating-trigger__btn {
    display: flex; align-items: center; gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    background: var(--color-primary-gradient); color: #fff;
    border-radius: var(--radius-full);
    font-size: var(--text-sm); font-weight: var(--font-semibold);
    box-shadow: var(--shadow-glow);
    transition: all var(--transition-base);
}
.floating-trigger__btn:hover { transform: translateY(-2px); box-shadow: 0 0 40px var(--color-primary-glow); }

/* Floating Panel */
.floating-panel {
    position: fixed; inset: 0; z-index: var(--z-modal);
    opacity: 0; visibility: hidden; pointer-events: none;
    transition: opacity var(--transition-base), visibility var(--transition-base);
}
.floating-panel.is-open { opacity: 1; visibility: visible; pointer-events: auto; }
.floating-panel__overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.5); backdrop-filter: blur(4px); }
.floating-panel__content {
    position: absolute; top: 0; right: 0; bottom: 0;
    width: 100%; max-width: 520px;
    background: var(--color-bg-primary); border-left: 1px solid var(--color-border);
    padding: var(--space-8); overflow-y: auto;
    transform: translateX(100%);
    transition: transform var(--transition-slow);
}
.floating-panel.is-open .floating-panel__content { transform: translateX(0); }
.floating-panel__close {
    position: absolute; top: var(--space-4); right: var(--space-4);
    width: 36px; height: 36px;
    display: flex; align-items: center; justify-content: center;
    border-radius: var(--radius-sm); color: var(--color-text-secondary);
    transition: background var(--transition-fast), color var(--transition-fast);
}
.floating-panel__close:hover { background: rgba(255,255,255,0.06); color: var(--color-text-primary); }

@media (max-width: 1024px) {
    .header__nav, .header__cta { display: none; }
    .header__burger { display: flex; }
    .mobile-menu { display: block; }
}
@media (max-width: 640px) {
    .floating-trigger__btn span { display: none; }
    .floating-panel__content { max-width: 100%; }
}