:root {
    --bg-color: #fcfcfc;
    --text-primary: #1a1a1a;
    --text-secondary: #5a5a5a;
    --accent-color: #000000;
    --border-color: rgba(0, 0, 0, 0.08);
    --font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    /* Soft noise texture and gradient for premium feel */
    background-image: radial-gradient(circle at 50% 10%, rgba(255, 255, 255, 1) 0%, rgba(240, 240, 245, 0.5) 100%);
    background-size: cover;
    background-attachment: fixed;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

/* Background Glow Effect */
.bg-glow {
    position: fixed;
    top: 50%;
    left: 50%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(200, 220, 255, 0.15) 0%, rgba(255, 255, 255, 0) 70%);
    transform: translate(-50%, -50%);
    z-index: -1;
    pointer-events: none;
    filter: blur(40px);
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.3;
}

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

/* Header (Glassmorphism) */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 24px 60px;
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.header.scrolled {
    padding: 16px 60px;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    text-transform: uppercase;
}

.nav {
    display: flex;
    gap: 36px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    position: relative;
    padding: 8px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.user-actions {
    display: flex;
    align-items: center;
}

.login-icon {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 30px;
    background: transparent;
    transition: all 0.3s ease;
}

.login-icon:hover {
    background: rgba(0, 0, 0, 0.05);
}

/* Main Content */
.main-content {
    padding-top: 160px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 60px 20px;
    max-width: 900px;
    width: 100%;
}

.hero-title {
    font-size: 3.5rem;
    letter-spacing: -1.5px;
    margin-bottom: 24px;
    word-break: keep-all;
    font-weight: 800;
    color: #000;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 60px;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.event-details {
    font-size: 1.15rem;
    margin-bottom: 60px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    color: var(--text-primary);
}

.event-details p {
    font-weight: 500;
}

.event-details .highlight {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Call to Action Button */
.cta-button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    background-color: var(--accent-color);
    color: #ffffff;
    padding: 18px 56px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 4px;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.cta-button:hover::before {
    left: 100%;
}

.cta-button span {
    position: relative;
    z-index: 1;
}

/* Invitation Letter Section */
.invitation-letter {
    text-align: center;
    padding: 80px 40px;
    max-width: 900px;
    width: 100%;
    position: relative;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 24px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.03);
    margin-bottom: 100px;
    margin-top: 40px;
}

.letter-content {
    display: flex;
    flex-direction: column;
    gap: 36px;
}

.letter-content p {
    font-size: 1.3rem;
    font-weight: 400;
    line-height: 1.9;
    color: #333;
    word-break: keep-all;
}

.letter-content .sender {
    font-weight: 700;
    margin-top: 20px;
    font-size: 1.4rem;
    color: var(--accent-color);
}

.footnote {
    margin-top: 60px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    font-size: 0.95rem;
    color: var(--text-secondary);
    text-align: left;
    line-height: 1.6;
}

/* Footer */
.footer {
    width: 100%;
}

.footer-top {
    background: linear-gradient(135deg, #1c1c1c, #0a0a0a);
    color: #ffffff;
    padding: 60px 20px;
    display: flex;
    justify-content: center;
    gap: 100px;
    text-align: center;
}

.sponsor-info {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sponsor-info h3 {
    font-size: 0.9rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.sponsor-info p {
    font-size: 1.25rem;
    font-weight: 600;
}

.footer-bottom {
    background-color: #f0f0f0;
    padding: 60px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-secondary);
}

.account-info {
    margin-bottom: 40px;
    text-align: center;
    max-width: 600px;
    width: 100%;
}

.account-title {
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.account-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.account-list p {
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.6);
    padding: 12px 20px;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

.account-list p span {
    font-weight: 600;
    color: var(--text-primary);
}

.copyright {
    font-size: 0.9rem;
    opacity: 0.8;
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Animations */
.slide-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s cubic-bezier(0.16, 1, 0.3, 1), transform 1s cubic-bezier(0.16, 1, 0.3, 1);
    will-change: opacity, transform;
}

.slide-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .header {
        padding: 20px 40px;
    }

    .nav {
        display: none;
        /* In a real app, this would be a hamburger menu */
    }
}

@media (max-width: 768px) {
    .header {
        padding: 20px;
    }

    .header-container {
        justify-content: center;
        /* Center logo on mobile */
    }

    .user-actions {
        display: none;
        /* Hide login on very small screens for clean look */
    }

    .main-content {
        padding-top: 120px;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .letter-content p {
        font-size: 1.1rem;
    }

    .invitation-letter {
        padding: 40px 20px;
        margin-top: 20px;
    }

    .footer-top {
        flex-direction: column;
        gap: 40px;
    }

    .account-list p {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
        text-align: left;
    }
}

/* Dropdown Navigation */
.nav-item-dropdown {
    position: relative;
    padding: 8px 0;
    padding-bottom: 24px;
    /* expanded hit area */
    margin-bottom: -24px;
}

.nav-item-dropdown .nav-link {
    padding: 0;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    border-radius: 12px;
    padding: 12px 0;
    min-width: 240px;
    z-index: 1001;
}

.nav-item-dropdown:hover .dropdown-content {
    display: flex;
    flex-direction: column;
    animation: fadeInDown 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translate(-50%, 10px);
    }

    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

.dropdown-content a {
    padding: 10px 24px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.dropdown-content a:hover {
    color: var(--accent-color);
    background-color: rgba(0, 0, 0, 0.03);
    font-weight: 600;
}

/* Subpage Styles */
.page-header {
    width: 100%;
    text-align: center;
    padding: 80px 20px 40px;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -1px;
    color: var(--accent-color);
}

.page-section {
    width: 100%;
    max-width: 1000px;
    padding: 0 20px;
    margin-bottom: 100px;
    min-height: 40vh;
}

.placeholder-content {
    background: rgba(255, 255, 255, 0.6);
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-radius: 20px;
    padding: 80px 40px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.02);
}