:root {
    --primary-color: #f59e0b; /* Amber 500 */
    --primary-hover: #d97706; /* Amber 600 */
    --bg-color: #111827; /* Gray 900 */
    --surface-color: #1f2937; /* Gray 800 */
    --text-color: #f3f4f6; /* Gray 100 */
    --text-muted: #9ca3af; /* Gray 400 */
    --divider-color: #374151; /* Gray 700 */
    --font-family: 'Noto Sans KR', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

ul {
    list-style: none;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    background-color: rgba(17, 24, 39, 0.9);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 0;
    border-bottom: 1px solid var(--divider-color);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
}

.logo-text {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--primary-color);
}

.nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav a:not(.btn-download-small) {
    font-weight: 500;
    color: var(--text-muted);
}

.nav a:not(.btn-download-small):hover {
    color: var(--primary-color);
}

.btn-download-small {
    background-color: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 0.375rem;
    font-weight: 700;
    font-size: 0.875rem;
}

.btn-download-small:hover {
    background-color: var(--primary-hover);
}

/* Sections */
section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

/* Hero */
.hero {
    padding-top: 8rem; /* header height + spacing */
    min-height: 80vh;
    display: flex;
    align-items: center;
    background: linear-gradient(to bottom, var(--bg-color), var(--surface-color));
}

.hero-content {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.hero-text {
    flex: 1;
}

.hero-title-img {
    max-width: 300px;
    height: auto;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.btn-download {
    display: inline-block;
    background-color: var(--surface-color);
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    font-weight: 700;
    font-size: 1.125rem;
    cursor: default;
}

.btn-download.large {
    background-color: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
}

.btn-download.large:hover {
    background-color: var(--primary-hover);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.phone-frame {
    width: 100%;
    max-width: 300px;
    border-radius: 20px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    border: 8px solid #333;
}

/* Features */
.features {
    background-color: var(--bg-color);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-muted);
}

/* Gallery */
.gallery {
    background-color: var(--surface-color);
    overflow: hidden;
}

.gallery-slider {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    align-items: center;
}

.slider-track-container {
    overflow: hidden;
    width: 100%;
    border-radius: 1rem;
    background-color: #000;
    aspect-ratio: 16/9; /* Or adjust based on your screenshot aspect ratio */
}

.slider-track {
    display: flex;
    transition: transform 0.3s ease-in-out;
    height: 100%;
}

.slider-slide {
    min-width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.slider-slide img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    padding: 1rem;
    cursor: pointer;
    z-index: 10;
    font-size: 1.5rem;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s;
}

.slider-btn:hover {
    background-color: rgba(0, 0, 0, 0.8);
}

.slider-btn.prev {
    left: -60px;
}

.slider-btn.next {
    right: -60px;
}

/* Download CTA */
.download-cta {
    text-align: center;
    background: linear-gradient(135deg, var(--surface-color), var(--bg-color));
}

.download-cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.download-cta p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

/* Footer */
.footer {
    background-color: #0b0f19;
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--divider-color);
}

.footer-links {
    margin-bottom: 1rem;
}

.footer-links a {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-links a:hover {
    color: var(--primary-color);
}

.divider {
    color: var(--divider-color);
    margin: 0 0.5rem;
}

.copyright {
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 0.5rem 0;
    }
    
    .nav {
        gap: 1rem;
    }

    .nav a:not(.btn-download-small) {
        display: none; /* Hide confusing links on mobile */
    }

    .hero-content {
        flex-direction: column-reverse;
        text-align: center;
    }

    .hero-title-img {
        margin: 0 auto 1.5rem;
    }
    
    .slider-btn.prev {
        left: 10px;
    }

    .slider-btn.next {
        right: 10px;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
}