/* Button Components */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-family: var(--font-body);
    /* Or display, depending on preference. Source Serif makes it feel editorial. */
    font-size: 1rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: all var(--transition-medium);
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--color-accent);
    color: var(--color-bg-primary);
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-2px);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--color-text-primary);
    color: var(--color-text-primary);
}

.btn-outline:hover {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
    transform: translateY(-2px);
}

/* Header & Nav */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: rgba(18, 18, 18, 0.85);
    /* Glassmorphism background */
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform var(--transition-medium);
}

.header.hidden {
    transform: translateY(-100%);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.header .btn {
    display: none;
}

@media (min-width: 768px) {
    .header .btn {
        display: inline-flex;
    }
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.logo img {
    height: 32px;
    width: auto;
}

.nav-desktop {
    display: none;
}

@media (min-width: 768px) {
    .nav-desktop {
        display: flex;
        gap: 2rem;
    }
}

.nav-link {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-text-primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent);
    transition: width var(--transition-medium);
}

.nav-link:hover::after {
    width: 100%;
}

/* Service Cards */
.service-card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    padding: var(--space-lg);
    transition: all var(--transition-medium);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.service-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.service-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--space-md);
}

.service-number {
    font-family: var(--font-display);
    font-size: 3rem;
    color: var(--color-bg-tertiary);
    line-height: 1;
    transition: color var(--transition-medium);
}

.service-card:hover .service-number {
    color: var(--color-accent-subtle);
}

.service-title {
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
}

.service-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
    flex-grow: 1;
}

/* Expandable details within card */
.service-details {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.service-card.expanded .service-details {
    max-height: 500px;
    /* Arbitrary large height */
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--color-border);
}

.service-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: var(--space-sm);
}

.tag {
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-secondary);
    border-radius: 999px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}