:root {
    --primary-bg: #121212;
    --card-bg: #1e1e1e;
    --accent-color: #00b8ff;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --card-hover: #2d2d2d;
    --gradient-start: rgba(18, 18, 18, 0.8);
    --gradient-end: rgba(18, 18, 18, 0.95);
    --gold: #d4af37;
    --gold-light: #f1c454;
    --gold-dark: #a67c00;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans KR', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--primary-bg);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow-x: hidden;
}

/* Star background */
.stars, .twinkling {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
    z-index: -1;
}

.stars {
    background: #000 url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==') repeat top center;
    z-index: -2;
}

.twinkling {
    background: transparent url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==') repeat top center;
    animation: move-twink-back 200s linear infinite;
}

@keyframes move-twink-back {
    from { background-position: 0 0; }
    to { background-position: -10000px 5000px; }
}

.container {
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    flex-grow: 1;
    position: relative;
    z-index: 1;
}

/* Logo Styles */
.logo {
    text-align: center;
    margin-bottom: 2.5rem;
    position: relative;
    z-index: 2;
}

.logo-text {
    display: inline-block;
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ffffff 10%, #888888 50%, #ffffff 90%);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    position: relative;
    letter-spacing: -0.5px;
    text-transform: uppercase;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.logo-text::before {
    content: '';
    position: absolute;
    top: -5px;
    left: -5px;
    right: -5px;
    bottom: -5px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), rgba(255, 255, 255, 0));
    border-radius: 8px;
    z-index: -1;
    opacity: 0.3;
}

.logo-text .dot {
    color: var(--accent-color);
    font-weight: 900;
    text-shadow: 0 0 15px rgba(0, 184, 255, 0.7);
    position: relative;
    display: inline-block;
    animation: pulse 3s infinite;
}

.logo-text .how {
    background: linear-gradient(135deg, var(--accent-color) 10%, #80dbff 50%, var(--accent-color) 90%);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    font-weight: 900;
    position: relative;
    letter-spacing: -0.5px;
    -webkit-text-fill-color: transparent;
    animation: shimmer 3s infinite;
    filter: drop-shadow(0 0 8px rgba(0, 184, 255, 0.5));
}

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

@keyframes shimmer {
    0% { background-position: -100px; }
    100% { background-position: 200px; }
}

/* Search Box */
.search-box {
    max-width: 600px;
    margin: 0 auto 2.5rem;
}

.search-wrapper {
    position: relative;
    background-color: rgba(255, 255, 255, 0.08);
    border-radius: 50px;
    overflow: hidden;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
}

.search-wrapper:focus-within {
    background-color: rgba(255, 255, 255, 0.12);
    box-shadow: 0 0 0 2px var(--accent-color), 0 4px 20px rgba(0, 184, 255, 0.2);
}

.search-input {
    flex: 1;
    padding: 15px 24px;
    border: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 1.1rem;
    outline: none;
}

.search-input::placeholder {
    color: var(--text-secondary);
}

.search-button {
    background-color: var(--accent-color);
    color: #000000;
    font-weight: 600;
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    margin: 5px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 15px rgba(0, 184, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
}

.search-button:hover {
    background-color: #0099ff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 184, 255, 0.4);
}

.info-text {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-size: 0.9rem;
}

/* Card Container */
.card-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

/* Card Styles */
.card {
    position: relative;
    border-radius: 14px;
    overflow: hidden;
    text-decoration: none;
    color: var(--text-primary);
    background-color: var(--card-bg);
    height: 160px;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transform-style: preserve-3d;
    perspective: 1000px;
}

.card:hover {
    transform: translateY(-12px) rotateX(8deg) scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), 0 0 20px rgba(0, 184, 255, 0.2);
    border-color: rgba(0, 184, 255, 0.3);
}

/* Card Background */
.card-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    opacity: 0.8;
    background-size: cover;
    background-position: center;
    transition: all 0.4s ease;
}

.card:hover .card-bg {
    transform: scale(1.05);
    opacity: 0.9;
}

.card-bg::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, var(--gradient-start), var(--gradient-end));
}

/* Card Content */
.card-content {
    position: relative;
    z-index: 2;
    padding: 1.2rem;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}

.card-title {
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 0.4rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.card-description {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

/* Card Shine Effect */
.card-shine {
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
            45deg,
            rgba(255, 255, 255, 0) 0%,
            rgba(255, 255, 255, 0.03) 30%,
            rgba(255, 255, 255, 0.1) 45%,
            rgba(255, 255, 255, 0.03) 60%,
            rgba(255, 255, 255, 0) 100%
    );
    transform: rotate(30deg);
    z-index: 3;
    pointer-events: none;
    transition: all 0.4s ease;
    opacity: 0;
}

.card:hover .card-shine {
    animation: shine 2s infinite;
    opacity: 1;
}

@keyframes shine {
    0% { transform: rotate(30deg) translate(-200px, -100px); }
    100% { transform: rotate(30deg) translate(200px, 100px); }
}

/* Card Decoration (corners) */
.card-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 4;
}

.corner {
    position: absolute;
    width: 15px;
    height: 15px;
    border-color: rgba(255, 255, 255, 0.15);
    transition: all 0.3s ease;
}

.card:hover .corner {
    border-color: var(--accent-color);
    box-shadow: 0 0 5px rgba(0, 184, 255, 0.5);
}

.top-left {
    top: 6px;
    left: 6px;
    border-top: 2px solid;
    border-left: 2px solid;
    border-top-left-radius: 5px;
}

.top-right {
    top: 6px;
    right: 6px;
    border-top: 2px solid;
    border-right: 2px solid;
    border-top-right-radius: 5px;
}

.bottom-left {
    bottom: 6px;
    left: 6px;
    border-bottom: 2px solid;
    border-left: 2px solid;
    border-bottom-left-radius: 5px;
}

.bottom-right {
    bottom: 6px;
    right: 6px;
    border-bottom: 2px solid;
    border-right: 2px solid;
    border-bottom-right-radius: 5px;
}

/* Card Icons */
.card-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 48px;
    color: rgba(255, 255, 255, 0.1);
    z-index: 1;
    transition: all 0.3s ease;
}

.card:hover .card-icon {
    color: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%) scale(1.1);
}

/* Card Badges */
.card-featured-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    background: linear-gradient(135deg, var(--accent-color), #80dbff);
    color: #000;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    z-index: 5;
    animation: pulse-badge 2s infinite;
}

@keyframes pulse-badge {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.05);
        opacity: 0.9;
    }
}

.card-creator {
    position: absolute;
    top: 10px;
    right: 10px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), rgba(0, 184, 255, 0.2));
    color: var(--text-primary);
    font-size: 0.7rem;
    font-weight: 500;
    padding: 3px 8px;
    border-radius: 10px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
    z-index: 5;
    backdrop-filter: blur(2px);
    opacity: 0.8;
    transition: all 0.3s ease;
}

.card:hover .card-creator {
    opacity: 1;
    background: linear-gradient(135deg, rgba(0, 184, 255, 0.2), rgba(255, 255, 255, 0.1));
    transform: translateY(-2px);
}

/* Featured Card */
.featured-card {
    grid-column: span 2;
    height: 200px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3), 0 0 20px rgba(0, 184, 255, 0.3);
    border: 1px solid rgba(0, 184, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.featured-card .card-content {
    padding: 1.5rem;
}

.featured-card .card-title {
    font-size: 1.5rem;
    margin-bottom: 0.6rem;
}

.featured-card .card-description {
    font-size: 1rem;
}

.featured-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg,
    rgba(0, 184, 255, 0.1) 0%,
    rgba(0, 184, 255, 0) 50%,
    rgba(0, 184, 255, 0.1) 100%);
    z-index: 2;
}

.featured-card:hover {
    transform: translateY(-15px) rotateX(8deg) scale(1.02);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4), 0 0 30px rgba(0, 184, 255, 0.4);
}

/* Card Background Gradients */
.card-datalake {
    background: linear-gradient(135deg, #1abc9c, #16a085);
}

.card-bitcoin {
    background: linear-gradient(135deg, #F7931A, #e6851a);
}

.card-market {
    background: linear-gradient(135deg, #16c784, #0fa68b);
}

.card-binance {
    background: linear-gradient(135deg, #F0B90B, #d4a00a);
}

.card-ai {
    background: linear-gradient(135deg, #9c27b0, #7b1fa2);
}

.card-util {
    background: linear-gradient(135deg, #4CAF50, #388e3c);
}

.card-hero {
    background: linear-gradient(135deg, #E91E63, #c2185b);
}

.card-security {
    background: linear-gradient(135deg, #607D8B, #455a64);
}

.card-models {
    background: linear-gradient(135deg, #3F51B5, #303f9f);
}

.card-facebook {
    background: linear-gradient(135deg, #1877F2, #1565c0);
}

.card-news {
    background: linear-gradient(135deg, #3498db, #2c3e50);
}

.card-korea {
    background: linear-gradient(135deg, #e74c3c, #8e44ad);
}

.card-sales {
    background: linear-gradient(135deg, #f39c12, #d35400);
}

.card-jobs {
    background: linear-gradient(135deg, #1abc9c, #16a085);
}

.card-blockchain {
    background: linear-gradient(135deg, #ff9500, #ff5e3a);
}

.card-metaverse {
    background: linear-gradient(135deg, #7f00ff, #e100ff);
}

.card-whitepaper {
    background: linear-gradient(135deg, #2c3e50, #4a6491);
}

.card-hashrate {
    background: linear-gradient(135deg, #2a4365, #4c51bf);
}

.card-clip {
    background: linear-gradient(135deg, #00B8FF, #0099cc);
}

/* Section Titles */
.section-title {
    margin: 3rem 0 1.5rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    text-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    position: relative;
}

.section-title i {
    color: var(--accent-color);
    margin-right: 0.8rem;
    font-size: 1.2em;
    filter: drop-shadow(0 0 8px rgba(0, 184, 255, 0.5));
}

.section-title::after {
    content: '';
    flex-grow: 1;
    height: 1px;
    background: linear-gradient(to right,
    rgba(0, 184, 255, 0.5),
    rgba(255, 255, 255, 0.05)
    );
    margin-left: 1rem;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    background-color: rgba(0, 0, 0, 0.5);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    position: relative;
    z-index: 1;
    margin-top: 3rem;
}

footer p {
    margin-bottom: 0.5rem;
}

footer p:last-child {
    margin-bottom: 0;
    font-weight: 500;
    color: var(--accent-color);
}

/* Media Queries */
@media (min-width: 1400px) {
    .card-container {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }

    .card {
        height: 170px;
    }

    .featured-card {
        height: 220px;
    }
}

@media (max-width: 768px) {
    .logo-text {
        font-size: 2.2rem;
    }

    .section-title {
        font-size: 1.3rem;
    }

    .card-title {
        font-size: 1.1rem;
    }

    .featured-card {
        grid-column: span 1;
        height: 180px;
    }

    .featured-card .card-title {
        font-size: 1.3rem;
    }

    .featured-card .card-description {
        font-size: 0.9rem;
    }

    .card-container {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1.5rem 1rem;
    }

    .logo-text {
        font-size: 1.8rem;
    }

    .logo {
        margin-bottom: 1.5rem;
    }

    .search-input {
        padding: 12px 20px;
        font-size: 1rem;
    }

    .card-container {
        gap: 1rem;
        grid-template-columns: 1fr;
    }

    .card {
        height: 140px;
    }

    .featured-card {
        height: 160px;
    }

    .card-content {
        padding: 1rem;
    }

    .card-icon {
        font-size: 36px;
    }

    .section-title {
        font-size: 1.2rem;
        margin: 2rem 0 1rem;
    }
}

/* Loading Animation */
.card {
    opacity: 0;
    transform: translateY(30px);
}

.card.loaded {
    opacity: 1;
    transform: translateY(0);
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

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

/* Focus styles for keyboard navigation */
.card:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

.search-input:focus,
.search-button:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}