:root {
    --bg-color: #f0f4f8;
    --card-bg: rgba(255, 255, 255, 0.85);
    --text-color: #1e293b;
    --text-muted: #64748b;
    --accent-color: #2563eb;
    --action-color: #059669;
    --border-color: rgba(148, 163, 184, 0.2);
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    background-image:
        radial-gradient(at 0% 0%, rgba(219, 234, 254, 0.8) 0, transparent 50%),
        radial-gradient(at 100% 100%, rgba(224, 231, 255, 0.8) 0, transparent 50%);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-attachment: fixed;
}

.container {
    max-width: 960px;
    width: 90%;
    padding: 2.5rem 1rem;
}

header {
    text-align: center;
    margin-bottom: 2.5rem;
    animation: fadeInDown 0.8s ease-out;
}

h1 {
    font-size: 3rem;
    font-weight: 800;
    margin: 0;
    background: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.05em;
}

.subtitle {
    margin-top: 0.5rem;
    color: var(--text-muted);
    font-size: 1.1rem;
    font-weight: 300;
}

/* Header Buttons */
.header-btn {
    display: inline-block;
    padding: 0.45rem 1.2rem;
    border-radius: 9999px;
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    transition: transform 0.2s, box-shadow 0.2s;
}

.header-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.header-btn--dark {
    background: linear-gradient(135deg, #0f172a, #1e293b);
    color: #e2e8f0;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.header-btn--accent {
    background: linear-gradient(135deg, #2563eb, #7c3aed);
    color: #fff;
}

/* Layer Labels */
.layer-label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--text-muted);
    font-weight: 700;
    margin-bottom: 0.75rem;
    padding-left: 0.5rem;
    border-left: 3px solid var(--accent-color);
}

/* Service Grid */
.service-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

/* Service Card */
.service-card {
    --card-accent: #2563eb;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 1.5rem;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--card-accent);
    opacity: 0;
    transition: opacity 0.3s;
}

.service-card:hover {
    transform: translateY(-4px);
    border-color: var(--card-accent);
    box-shadow: 0 16px 32px -8px rgba(0, 0, 0, 0.1);
    background: rgba(255, 255, 255, 0.95);
}

.service-card:hover::before {
    opacity: 1;
}

.service-card:focus-visible {
    outline: 2px solid var(--card-accent);
    outline-offset: 2px;
}

/* Card Header */
.service-card__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.service-card__icon {
    font-size: 1.5rem;
    line-height: 1;
}

.service-card__status {
    font-size: 0.65rem;
    padding: 0.15rem 0.5rem;
    border-radius: 9999px;
    background: rgba(16, 185, 129, 0.1);
    color: #059669;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Card Name */
.service-card__name {
    font-size: 1.2rem;
    font-weight: 800;
    margin: 0 0 0.15rem 0;
    color: var(--text-color);
}

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

/* Tagline */
.service-card__tagline {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin: 0 0 0.75rem 0;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Description */
.service-card__desc {
    font-size: 0.85rem;
    color: #475569;
    line-height: 1.6;
    margin: 0 0 1rem 0;
    flex: 1;
}

/* Tech Stack */
.service-card__tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
}

.service-card__tech span {
    font-size: 0.65rem;
    padding: 0.15rem 0.5rem;
    border-radius: 9999px;
    background: rgba(148, 163, 184, 0.12);
    color: var(--text-muted);
    font-weight: 500;
}

/* Wiki Link */
.service-card__wiki {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    font-size: 0.75rem;
    line-height: 1;
    cursor: pointer;
    opacity: 0.5;
    transition: opacity 0.2s, transform 0.2s;
    border-radius: 6px;
    padding: 0.15rem 0.35rem;
    color: var(--text-secondary, #64748b);
    text-decoration: none;
}
.service-card__wiki-icon {
    font-size: 1.1rem;
}
.service-card__wiki-label {
    font-family: inherit;
    font-weight: 500;
    letter-spacing: 0.01em;
}

.service-card__wiki:hover {
    opacity: 1;
    transform: scale(1.15);
    background: rgba(148, 163, 184, 0.12);
}

/* Arrow */
.service-card__arrow {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    font-size: 1.1rem;
    color: var(--text-muted);
    opacity: 0;
    transform: translateX(-4px);
    transition: all 0.3s;
}

.service-card:hover .service-card__arrow {
    opacity: 1;
    transform: translateX(0);
    color: var(--card-accent);
}

/* Copyright Section */
.copyright-section {
    margin-top: 0.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border-color);
    animation: fadeInUp 1s ease-out 0.45s backwards;
}

.copyright-container {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1rem 1.25rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.copyright-logo {
    width: 44px;
    height: 44px;
    border-radius: 8px;
    flex-shrink: 0;
}

.copyright-content {
    flex: 1;
}

.copyright-content h3 {
    font-size: 0.8rem;
    color: var(--accent-color);
    margin: 0 0 0.4rem 0;
    font-weight: 600;
}

.copyright-text {
    color: var(--text-muted);
    font-size: 0.75rem;
    line-height: 1.6;
    margin: 0;
}

.copyright-text.ko {
    margin-bottom: 0.35rem;
}

.highlight {
    color: #dc2626;
    font-weight: 500;
}

.copyright-notice {
    margin-top: 0.6rem;
    padding-top: 0.4rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.65rem;
    color: var(--text-muted);
    text-align: right;
}

/* Animations */
@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.layer-label {
    animation: fadeInUp 0.8s ease-out backwards;
}

.service-grid {
    animation: fadeInUp 0.8s ease-out backwards;
}

.layer-label:nth-of-type(1) { animation-delay: 0.1s; }
.service-grid:nth-of-type(1) { animation-delay: 0.15s; }
.layer-label:nth-of-type(2) { animation-delay: 0.25s; }
.service-grid:nth-of-type(2) { animation-delay: 0.3s; }
.layer-label:nth-of-type(3) { animation-delay: 0.4s; }
.service-grid:nth-of-type(3) { animation-delay: 0.45s; }

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1.5rem 1rem;
    }

    h1 {
        font-size: 2.25rem;
    }

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

    .service-card {
        padding: 1.25rem;
    }

    .copyright-container {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
}