/* =============================================
   CSS Custom Properties
   ============================================= */
:root {
    --color-white: #ffffff;
    --color-bg: #f8f8f8;
    --color-bg-alt: #f0f0f0;
    --color-card: #ffffff;
    --color-border: #e0e0e0;
    --color-text: #1a1a1a;
    --color-text-secondary: #555555;
    --color-text-muted: #888888;
    --color-accent: #333333;
    --color-accent-hover: #000000;

    --font-serif: 'Noto Serif SC', Georgia, 'Times New Roman', serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

    --transition-slow: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
    --transition-base: 0.3s ease;
    --transition-fast: 0.15s ease;

    --max-width: 1100px;
    --nav-height: 60px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    display: block;
}

/* =============================================
   Selection
   ============================================= */
::selection {
    background: var(--color-accent);
    color: var(--color-white);
}

/* =============================================
   Hero
   ============================================= */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 50%, #1a1a1a 100%);
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(255,255,255,0.03) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 50%, rgba(255,255,255,0.03) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 5rem;
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: 0.15em;
    margin-bottom: 1.5rem;
    opacity: 0;
    transform: translateY(30px);
    animation: heroFadeIn 1s var(--transition-slow) forwards;
}

.hero-subtitle {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    font-weight: 300;
    color: rgba(255, 255, 255, 0.6);
    letter-spacing: 0.3em;
    min-height: 1.7em;
}

.hero-subtitle .cursor {
    display: inline-block;
    width: 1px;
    height: 1.1em;
    background: rgba(255, 255, 255, 0.6);
    margin-left: 2px;
    vertical-align: text-bottom;
    animation: blink 1s step-end infinite;
}

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

.hero-scroll {
    position: absolute;
    bottom: 3rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    opacity: 0;
    animation: heroFadeIn 1s var(--transition-slow) 1.5s forwards;
}

.scroll-text {
    font-size: 0.7rem;
    font-weight: 300;
    letter-spacing: 0.2em;
    color: rgba(255, 255, 255, 0.4);
    text-transform: uppercase;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, rgba(255,255,255,0.4), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 0.4; transform: scaleY(1); }
    50% { opacity: 1; transform: scaleY(1.2); }
}

@keyframes heroFadeIn {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =============================================
   Navigation
   ============================================= */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    z-index: 100;
    background: rgba(248, 248, 248, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    transition: transform var(--transition-base);
}

.nav.visible {
    transform: translateY(0);
}

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

.nav-logo {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: 0.1em;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    font-size: 0.85rem;
    font-weight: 400;
    color: var(--color-text-secondary);
    letter-spacing: 0.05em;
    transition: color var(--transition-fast);
    position: relative;
}

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

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

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

/* =============================================
   Sections
   ============================================= */
.section {
    padding: 6rem 2rem;
}

.section-dark {
    background: var(--color-bg-alt);
}

.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2.2rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.section-desc {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    margin-bottom: 3.5rem;
    font-weight: 300;
}

/* =============================================
   Cards Grid
   ============================================= */
.cards-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2.5rem;
}

.card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 2.5rem;
    transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.card:hover {
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
    transform: translateY(-2px);
}

.card-number {
    font-family: var(--font-serif);
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-border);
    line-height: 1;
    margin-bottom: 1rem;
}

.card-title {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 1.25rem;
}

.card-text {
    font-size: 0.92rem;
    color: var(--color-text-secondary);
    line-height: 1.9;
    margin-bottom: 0.75rem;
}

.card-text:last-child {
    margin-bottom: 0;
}

/* =============================================
   Projects Grid
   ============================================= */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.project-card {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    background: var(--color-card);
    display: block;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.project-card-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,0,0,0.02) 0%, transparent 100%);
    pointer-events: none;
}

.project-card-content {
    position: relative;
    padding: 2.5rem 2rem;
    text-align: center;
}

.project-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.project-name {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 0.5rem;
}

.project-desc {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
    font-weight: 300;
}

.project-link {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-accent);
    letter-spacing: 0.05em;
    padding-bottom: 2px;
    border-bottom: 1px solid var(--color-accent);
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.project-card:hover .project-link {
    color: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
}

/* =============================================
   3D Print Grid
   ============================================= */
.print-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.print-item {
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    background: var(--color-card);
    min-height: 220px;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.print-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.07);
}

.print-item-tall {
    grid-row: span 2;
}

.print-image-wrap {
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.print-image-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.print-item:hover .print-image-wrap img {
    transform: scale(1.05);
}

.print-desc {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.print-desc p {
    font-size: 0.92rem;
    color: var(--color-text-secondary);
    line-height: 1.9;
    font-weight: 300;
}

/* =============================================
   Vision / Quote Section
   ============================================= */
.vision-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.vision-content .section-title {
    margin-bottom: 2rem;
}

.vision-quote {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 400;
    font-style: italic;
    color: var(--color-text);
    line-height: 1.8;
    margin: 0 0 2rem;
    padding: 0 1rem;
    position: relative;
}

.vision-text {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    line-height: 2;
    font-weight: 300;
}

/* =============================================
   Footer
   ============================================= */
.footer {
    border-top: 1px solid var(--color-border);
    background: var(--color-white);
    padding: 2.5rem 2rem;
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-text {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-weight: 300;
}

.footer-meta {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    font-weight: 300;
}

/* =============================================
   Reveal Animations (Intersection Observer)
   ============================================= */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
                transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* Stagger children */
.cards-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.cards-grid .reveal:nth-child(3) { transition-delay: 0.2s; }
.projects-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.projects-grid .reveal:nth-child(3) { transition-delay: 0.2s; }
.print-grid .reveal:nth-child(2) { transition-delay: 0.05s; }
.print-grid .reveal:nth-child(3) { transition-delay: 0.1s; }
.print-grid .reveal:nth-child(4) { transition-delay: 0.15s; }
.print-grid .reveal:nth-child(5) { transition-delay: 0.2s; }

/* =============================================
   Responsive
   ============================================= */
@media (max-width: 900px) {
    .hero-title {
        font-size: 3.5rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .print-grid {
        grid-template-columns: 1fr;
    }

    .print-item-tall {
        grid-row: span 1;
    }

    .section {
        padding: 4rem 1.5rem;
    }

    .card {
        padding: 2rem;
    }
}

@media (max-width: 600px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
        letter-spacing: 0.2em;
    }

    .nav-links {
        gap: 1.25rem;
    }

    .nav-link {
        font-size: 0.8rem;
    }

    .section-title {
        font-size: 1.7rem;
    }

    .cards-grid {
        gap: 1.5rem;
    }

    .card {
        padding: 1.5rem;
    }

    .card-number {
        font-size: 2.2rem;
    }

    .print-grid {
        grid-template-columns: 1fr;
    }

    .print-item-tall {
        grid-row: span 1;
    }

    .footer-inner {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
}