/* ── Base & Reset ── */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    color: #334155;
    background-color: #ffffff;
    overflow-x: hidden;
}

.dark body {
    color: #cbd5e1;
    background-color: #0f172a;
}

::selection {
    background-color: #0d9488;
    color: #ffffff;
}

/* ── Scrollbar ── */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: #f1f5f9;
}
::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}

/* ── Header ── */
#header {
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    background: rgba(255, 255, 255, 0.85);
    border-bottom: 1px solid rgba(148, 163, 184, 0.1);
}

.dark #header {
    background: rgba(15, 23, 42, 0.85);
    border-bottom: 1px solid rgba(148, 163, 184, 0.1);
}

#header.scrolled {
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.06);
}

/* ── Mobile Menu ── */
#mobileMenu.open {
    opacity: 1;
    pointer-events: all;
}

#mobileMenu.open .mobile-link {
    animation: slideIn 0.3s ease forwards;
}

#mobileMenu .mobile-link:nth-child(1) { animation-delay: 0.05s; }
#mobileMenu .mobile-link:nth-child(2) { animation-delay: 0.1s; }
#mobileMenu .mobile-link:nth-child(3) { animation-delay: 0.15s; }
#mobileMenu .mobile-link:nth-child(4) { animation-delay: 0.2s; }
#mobileMenu .mobile-link:nth-child(5) { animation-delay: 0.25s; }

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-12px); }
    to { opacity: 1; transform: translateX(0); }
}

.menu-line {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

#menuBtn.active .menu-line:nth-child(1) {
    transform: rotate(45deg) translate(4px, 4px);
}
#menuBtn.active .menu-line:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}
#menuBtn.active .menu-line:nth-child(3) {
    width: 1.25rem;
    transform: rotate(-45deg) translate(4px, -4px);
}

/* ── Hero Cards ── */
.card-main {
    transform: translateY(0);
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2