/* --- Header Premium --- */
.header {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur));
    -webkit-backdrop-filter: blur(var(--blur));
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-bottom: 1px solid var(--glass-border);
}
.header.scrolled {
    padding: 12px 0;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: var(--shadow-lg);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 52px;
    transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.logo img:hover {
    transform: scale(1.08) rotate(-2deg);
}

.nav ul {
    display: flex;
    gap: 40px;
    align-items: center;
}

.nav a {
    color: var(--primary);
    font-weight: 700;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
    position: relative;
    padding: 5px 0;
}

.nav a:not(.nav-btn)::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background: linear-gradient(to right, var(--accent), var(--primary-light));
    transition: width 0.4s ease;
    border-radius: 2px;
}

.nav a:not(.nav-btn):hover::after, .nav a.active::after {
    width: 100%;
}
.nav a:not(.nav-btn):hover {
    color: var(--accent);
}

.nav-btn {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff !important;
    padding: 12px 28px;
    border-radius: var(--radius-full);
    box-shadow: 0 4px 15px rgba(15, 34, 74, 0.2);
    font-size: 13px !important;
}
.nav-btn:hover {
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 10px 25px rgba(193, 39, 45, 0.3);
}