/* Reset & Base Setup */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Color Palette - Apple Minimalist Light Theme */
    --color-bg: #ffffff;
    --color-card-bg: #f5f5f7;
    --color-border: #e8e8ed;
    --color-border-hover: #d2d2d7;
    --color-text-primary: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-text-muted: #a1a1a6;
    --color-accent: #0066cc; /* Apple Royal Blue */
    --color-accent-hover: #0077ed;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro", "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    /* Grid & Spacing */
    --max-width: 760px;
    --transition-smooth: all 0.4s cubic-bezier(0.25, 1, 0.5, 1);
}

body {
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    word-break: keep-all;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Glassmorphism GNB */
.gnb {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 48px;
    background-color: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    z-index: 999;
}

.gnb-container {
    max-width: var(--max-width);
    height: 100%;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.gnb-logo {
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--color-text-primary);
    text-decoration: none;
    transition: var(--transition-smooth);
}

.gnb-logo:hover {
    opacity: 0.8;
}

.gnb-menu {
    display: flex;
    gap: 1.5rem;
}

.gnb-link {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: var(--transition-smooth);
}

.gnb-link:hover {
    color: var(--color-text-primary);
}

/* Container */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header Section */
.header {
    padding-top: 8rem;
    padding-bottom: 3rem;
}

.logo {
    font-size: 3.25rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--color-text-primary);
    line-height: 1.15;
    margin-bottom: 0.75rem;
    opacity: 0;
    transform: translateY(15px);
    animation: fadeInIntro 0.6s cubic-bezier(0.25, 1, 0.5, 1) forwards;
}

.tagline {
    font-size: 1.15rem;
    font-weight: 400;
    letter-spacing: -0.01em;
    color: var(--color-text-secondary);
    max-width: 600px;
    opacity: 0;
    transform: translateY(15px);
    animation: fadeInIntro 0.6s cubic-bezier(0.25, 1, 0.5, 1) 0.15s forwards;
}

/* Main Content Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4.5rem;
}

/* Intro Section */
.intro-section {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInIntro 0.8s cubic-bezier(0.25, 1, 0.5, 1) 0.3s forwards;
}

.intro-text {
    font-size: 1.35rem;
    font-weight: 400;
    color: var(--color-text-primary);
    max-width: 720px;
    line-height: 1.6;
    letter-spacing: -0.02em;
}

/* Projects Section */
.projects-section {
    padding-bottom: 6rem;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInIntro 0.8s cubic-bezier(0.25, 1, 0.5, 1) 0.45s forwards;
}

.section-title {
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--color-text-primary);
    margin-bottom: 1.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
}

.projects-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

/* Project Cards */
.project-card {
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-border);
    border-radius: 18px;
    padding: 2.25rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    transition: var(--transition-smooth);
    position: relative;
    text-decoration: none;
    color: inherit;
}

.project-card:not(.disabled):hover {
    background-color: #ffffff;
    border-color: var(--color-border-hover);
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.04);
}

.project-card.disabled {
    cursor: default;
    pointer-events: none;
    opacity: 0.65;
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.project-title-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.project-title {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-text-primary);
    transition: var(--transition-smooth);
}

.project-arrow {
    font-size: 1.25rem;
    color: var(--color-text-primary);
    opacity: 0;
    transform: translate(-6px, 6px);
    transition: var(--transition-smooth);
    display: inline-block;
}

.project-card:not(.disabled):hover .project-arrow {
    opacity: 1;
    transform: translate(0, 0);
}

.project-card:not(.disabled):hover .project-title {
    color: var(--color-accent);
}

.project-status {
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.25rem 0.6rem;
    border-radius: 20px;
}

.project-status.completed {
    background-color: rgba(0, 102, 204, 0.08);
    color: var(--color-accent);
}

.project-status.processing {
    background-color: rgba(0, 0, 0, 0.04);
    color: var(--color-text-secondary);
}

.project-desc {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.project-tags span {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    background-color: rgba(0, 0, 0, 0.03);
    padding: 0.25rem 0.6rem;
    border-radius: 6px;
    transition: var(--transition-smooth);
}

.project-card:not(.disabled):hover .project-tags span {
    background-color: rgba(0, 0, 0, 0.05);
}

/* Footer Section */
.footer {
    border-top: 1px solid var(--color-border);
    padding: 2.5rem 0;
    margin-top: auto;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.copyright {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.contact-link {
    font-size: 0.8rem;
    color: var(--color-accent);
    text-decoration: none;
    transition: var(--transition-smooth);
    font-weight: 500;
}

.contact-link:hover {
    color: var(--color-accent-hover);
    text-decoration: underline;
}

/* Keyframes for smooth initial load */
@keyframes fadeInIntro {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .gnb-container {
        padding: 0 1.25rem;
    }
    
    .container {
        padding: 0 1.25rem;
    }
    
    .header {
        padding-top: 6rem;
        padding-bottom: 2rem;
    }
    
    .logo {
        font-size: 2.5rem;
    }
    
    .intro-text {
        font-size: 1.2rem;
    }
    
    .projects-section {
        padding-bottom: 4rem;
    }
    
    .main-content {
        gap: 3.5rem;
    }
    
    .project-card {
        padding: 1.75rem;
    }
}