/* hub.css - Responsive & Layout Fixed */
:root {
    --nav-bg: rgba(0, 0, 0, 0.85);
    --nav-text: #ffffff;
    --accent: #0366d6;
    --transition: all 0.3s ease;
}

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

body, html {
    font-family: 'Poppins', 'Noto Sans KR', sans-serif;
    background-color: #1a1a1a;
    color: white;
    min-height: 100vh;
    overflow-x: hidden; /* 가로 스크롤 방지 */
}

/* Navigation */
.hub-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5%;
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.hub-nav .logo {
    font-weight: 700;
    font-size: 1.2rem;
    letter-spacing: 2px;
    color: white;
    white-space: nowrap;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 25px;
}

.nav-links a {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.6);
    font-weight: 500;
    font-size: 0.9rem;
    transition: var(--transition);
    padding: 5px 0;
    border-bottom: 2px solid transparent;
    letter-spacing: 1px;
}

.nav-links a:hover, .nav-links a.active {
    color: white;
    border-bottom: 2px solid var(--accent);
}

/* Exhibition Container */
#exhibition-container {
    padding-top: 70px; /* nav height */
    width: 100%;
    min-height: 100vh;
    position: relative;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: calc(100vh - 70px);
    text-align: center;
    padding: 20px;
}

.welcome-screen h1 {
    font-size: clamp(2rem, 8vw, 3.5rem);
    margin-bottom: 20px;
    background: linear-gradient(45deg, #fff, #888);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.welcome-screen p {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.6);
}

/* Loading State */
#exhibition-container.loading {
    opacity: 0.3;
    pointer-events: none;
    transition: opacity 0.3s;
}

/* Error State */
.error {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 50vh;
    color: #ff6b6b;
    font-weight: 600;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .hub-nav {
        padding: 0 20px;
        height: 60px;
    }
    
    .nav-links {
        gap: 15px;
    }
    
    .nav-links a {
        font-size: 0.8rem;
    }
    
    #exhibition-container {
        padding-top: 60px;
    }
}

@media (max-width: 480px) {
    .hub-nav {
        flex-direction: column;
        justify-content: center;
        height: auto;
        padding: 15px 0;
    }
    
    .hub-nav .logo {
        margin-bottom: 10px;
        font-size: 1rem;
    }
    
    .nav-links {
        gap: 20px;
    }
    
    #exhibition-container {
        padding-top: 90px; /* logo + links height approx */
    }
}