/* ===========================
   HEADER
   =========================== */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: var(--z-sticky);
    transition: all var(--transition-base);
}

.header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 15, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: var(--border-subtle);
    opacity: 0;
    transition: opacity var(--transition-base);
}

[data-theme="light"] .header::before {
    background: rgba(245, 245, 250, 0.85);
}

.header.scrolled::before {
    opacity: 1;
}

.header__inner {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-6);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    z-index: 1;
}

/* Logo */
.header__logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    text-decoration: none;
    font-weight: var(--fw-bold);
    font-size: var(--fs-lg);
    color: var(--text-primary);
}

.header__logo-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.header__logo-icon svg {
    width: 100%;
    height: 100%;
    display: block;
}

/* Navigation */
.nav__list {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.nav__link {
    padding: var(--space-2) var(--space-4);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.nav__link:hover {
    color: var(--text-primary);
    background: var(--bg-glass-hover);
}

.nav__link.active {
    color: var(--accent-primary);
    background: rgba(var(--accent-primary-rgb), 0.1);
}

/* Theme Toggle */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: var(--border-subtle);
    border-radius: var(--radius-md);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: var(--fs-lg);
    transition: all var(--transition-fast);
}

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

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    display: block;
    height: 2px;
    width: 100%;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translateY(5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translateY(-5px);
}

/* ===========================
   FOOTER
   =========================== */

.footer {
    background: var(--bg-secondary);
    border-top: var(--border-subtle);
    padding: var(--space-16) 0 var(--space-8);
    position: relative;
    z-index: var(--z-base);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-8);
    margin-bottom: var(--space-12);
}

.footer__brand {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.footer__brand-name {
    font-size: var(--fs-lg);
    font-weight: var(--fw-bold);
    color: var(--text-primary);
}

.footer__brand-desc {
    font-size: var(--fs-sm);
    color: var(--text-secondary);
    line-height: var(--lh-relaxed);
    max-width: 300px;
}

.footer__section-title {
    font-size: var(--fs-sm);
    font-weight: var(--fw-semibold);
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-4);
}

.footer__links {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer__link {
    font-size: var(--fs-sm);
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer__bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--space-8);
    border-top: var(--border-subtle);
}

.footer__copyright {
    font-size: var(--fs-xs);
    color: var(--text-tertiary);
}

/* ===========================
   GRID SYSTEM
   =========================== */

.grid {
    display: grid;
    gap: var(--space-6);
}

.grid--2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid--3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid--4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ===========================
   MAIN CONTENT
   =========================== */

.main {
    min-height: 100vh;
    padding-top: var(--header-height);
}

/* ===========================
   PAGE HERO (Subpage)
   =========================== */

.page-hero {
    padding: var(--space-16) 0 var(--space-12);
    text-align: center;
    position: relative;
}

.page-hero__title {
    font-size: var(--fs-2xl);
    font-weight: var(--fw-extrabold);
    margin-bottom: var(--space-4);
}

.page-hero__desc {
    font-size: var(--fs-md);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===========================
   RESPONSIVE
   =========================== */

@media (max-width: 1024px) {
    .grid--4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer__grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-8);
    }
}

@media (max-width: 768px) {
    .grid--3 {
        grid-template-columns: repeat(2, 1fr);
    }

    .grid--2 {
        grid-template-columns: 1fr;
    }

    .section {
        padding: var(--space-16) 0;
    }

    /* Mobile Navigation */
    .nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--bg-primary);
        padding: var(--space-8) var(--space-6);
        transform: translateX(100%);
        transition: transform var(--transition-base);
        z-index: var(--z-overlay);
    }

    .nav.open {
        transform: translateX(0);
    }

    .nav__list {
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-2);
    }

    .nav__link {
        padding: var(--space-4) var(--space-4);
        font-size: var(--fs-lg);
    }

    .mobile-menu-btn {
        display: flex;
    }

    .footer__grid {
        grid-template-columns: 1fr;
        gap: var(--space-6);
    }

    .footer__bottom {
        flex-direction: column;
        gap: var(--space-4);
        text-align: center;
    }
}

@media (max-width: 480px) {

    .grid--3,
    .grid--2 {
        grid-template-columns: 1fr;
    }

    .container {
        padding: 0 var(--space-4);
    }
}