/* =============================================
   SEJONG AI — PREMIUM DESIGN SYSTEM v2
   ============================================= */

:root {
    --black: #000;
    --white: #fff;
    --off-white: #f5f5f7;
    --gray-100: #e8e8ed;
    --gray-400: #86868b;
    --gray-600: #515154;
    --gray-800: #1d1d1f;
    --dark-bg: #0a0a0a;
    --dark-surface: #111;
    --accent-blue: #0071e3;
    --accent-blue-hover: #0077ed;
    --font-serif: 'Noto Serif KR', 'Georgia', serif;
    --font-sans: 'Inter', system-ui, sans-serif;
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* ─── RESET ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: var(--font-sans);
    background: var(--black);
    color: var(--white);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; width: 100%; }
address { font-style: normal; }

/* ─── NAVBAR ─── */
#navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 5%;
    transition: background 0.4s var(--transition-smooth),
                padding 0.4s var(--transition-smooth);
}
#navbar.scrolled {
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 0.9rem 5%;
    border-bottom: 1px solid rgba(255,255,255,0.06);
}
.nav-logo {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}
.nav-logo span { color: #6366f1; }
.nav-links {
    display: flex;
    gap: 2.5rem;
}
.nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: rgba(255,255,255,0.7);
    transition: color 0.3s;
    letter-spacing: 0.01em;
}
.nav-links a:hover { color: var(--white); }
.btn-nav {
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.55rem 1.4rem;
    border-radius: 9999px;
    background: var(--white);
    color: var(--black);
    transition: all 0.3s var(--transition-smooth);
}
.btn-nav:hover {
    background: var(--gray-100);
    transform: translateY(-1px);
}

/* ─── HERO SECTION ─── */
.hero {
    position: relative;
    width: 100%;
    height: 100vh;
    min-height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.hero-img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    transform: scale(1.05);
    transition: transform 8s ease-out;
}
.hero-img.loaded { transform: scale(1); }
.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        to bottom,
        rgba(0,0,0,0.25) 0%,
        rgba(0,0,0,0.55) 50%,
        rgba(0,0,0,0.9) 100%
    );
    z-index: 1;
}
.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 0 1.5rem;
    max-width: 900px;
}
.hero-eyebrow {
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: rgba(255,255,255,0.5);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 0.9s 0.2s var(--transition-smooth) forwards;
}
.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 7vw, 6.5rem);
    font-weight: 700;
    line-height: 1.05;
    letter-spacing: -0.02em;
    color: var(--white);
    margin-bottom: 1.75rem;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 1s 0.4s var(--transition-smooth) forwards;
}
.hero-sub {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: rgba(255,255,255,0.65);
    line-height: 1.7;
    margin-bottom: 3rem;
    font-weight: 300;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s 0.65s var(--transition-smooth) forwards;
}
.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s 0.85s var(--transition-smooth) forwards;
}
.btn-outline {
    padding: 0.85rem 2.2rem;
    border-radius: 9999px;
    border: 1px solid rgba(255,255,255,0.6);
    color: var(--white);
    font-size: 1rem;
    font-weight: 500;
    backdrop-filter: blur(10px);
    transition: all 0.35s var(--transition-smooth);
}
.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: var(--white);
    transform: translateY(-3px);
}
.btn-solid {
    padding: 0.85rem 2.2rem;
    border-radius: 9999px;
    background: var(--white);
    color: var(--black);
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.35s var(--transition-smooth);
}
.btn-solid:hover {
    background: var(--gray-100);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.4);
}

/* Hero Scroll Indicator */
.hero-scroll-indicator {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    opacity: 0;
    animation: fadeIn 1s 1.5s forwards;
}
.hero-scroll-indicator span {
    display: block;
    width: 1.5px;
    height: 60px;
    background: linear-gradient(to bottom, transparent, rgba(255,255,255,0.6));
    margin: 0 auto;
    animation: scrollPulse 2s infinite;
}

/* ─── SERVICE / PRODUCT SECTION ─── */
.services {
    background: var(--white);
    color: var(--black);
    padding: 0;
}
.service-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-height: 80vh;
    align-items: center;
}
.service-block.reverse {
    direction: rtl;
}
.service-block.reverse > * {
    direction: ltr;
}
.service-image {
    overflow: hidden;
    height: 100%;
    min-height: 500px;
}
.service-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.8s var(--transition-smooth);
}
.service-image:hover img { transform: scale(1.04); }
.service-text {
    padding: clamp(3rem, 8vw, 7rem) clamp(2.5rem, 6vw, 6rem);
}
.service-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    color: var(--gray-400);
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}
.service-headline {
    font-family: var(--font-serif);
    font-size: clamp(2.2rem, 4vw, 3.8rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--black);
    margin-bottom: 1.5rem;
}
.service-body {
    font-size: 1.05rem;
    color: var(--gray-600);
    line-height: 1.8;
    max-width: 420px;
    font-weight: 400;
    margin-bottom: 2rem;
}
.btn-text-link {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-blue);
    transition: color 0.3s, gap 0.3s;
    display: inline-block;
    letter-spacing: -0.01em;
}
.btn-text-link:hover { color: var(--accent-blue-hover); }
.btn-text-link.white { color: rgba(255,255,255,0.8); }
.btn-text-link.white:hover { color: var(--white); }

/* ─── ABOUT / TEAM SECTION ─── */
.about {
    background: var(--dark-bg);
    color: var(--white);
    padding: clamp(6rem, 12vw, 12rem) 5%;
    text-align: center;
}
.about-inner { max-width: 800px; margin: 0 auto; }
.about-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: rgba(255,255,255,0.35);
    text-transform: uppercase;
    margin-bottom: 2rem;
}
.about-headline {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 7vw, 6rem);
    font-weight: 700;
    line-height: 1.05;
    letter-spacing: -0.02em;
    margin-bottom: 2.5rem;
    background: linear-gradient(135deg, #fff 0%, rgba(255,255,255,0.6) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.about-body {
    font-size: clamp(1rem, 1.5vw, 1.15rem);
    color: rgba(255,255,255,0.5);
    line-height: 1.9;
    font-weight: 300;
    margin-bottom: 4rem;
}
.about-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 3rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}
.stat { text-align: center; }
.stat-num {
    display: block;
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--white);
}
.stat-desc {
    display: block;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.4);
    margin-top: 0.4rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}
.stat-divider {
    width: 1px;
    height: 50px;
    background: rgba(255,255,255,0.12);
}

/* ─── CONTACT SECTION ─── */
.contact {
    background: var(--off-white);
    color: var(--black);
    padding: clamp(6rem, 12vw, 12rem) 5%;
}
.contact-inner {
    max-width: 1100px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6rem;
    align-items: start;
}
.contact-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: var(--gray-400);
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}
.contact-headline {
    font-family: var(--font-serif);
    font-size: clamp(2.2rem, 4vw, 3.8rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--black);
}
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
    padding-top: 0.5rem;
}
.form-field {
    position: relative;
    border-bottom: 1.5px solid rgba(0,0,0,0.2);
    transition: border-color 0.3s;
}
.form-field:focus-within { border-color: var(--black); }
.form-field input,
.form-field textarea {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    font-family: var(--font-sans);
    font-size: 1rem;
    color: var(--black);
    padding: 1.2rem 0 0.6rem;
    resize: none;
}
.form-field label {
    position: absolute;
    top: 1rem;
    left: 0;
    font-size: 0.95rem;
    color: var(--gray-400);
    pointer-events: none;
    transition: all 0.25s var(--transition-smooth);
}
.form-field input:focus + label,
.form-field input:not(:placeholder-shown) + label,
.form-field textarea:focus + label,
.form-field textarea:not(:placeholder-shown) + label {
    top: -0.2rem;
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    color: var(--gray-600);
    text-transform: uppercase;
    font-weight: 600;
}
.btn-submit {
    margin-top: 1rem;
    padding: 1rem 0;
    background: var(--black);
    color: var(--white);
    border: none;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.35s var(--transition-smooth);
    position: relative;
    overflow: hidden;
}
.btn-submit::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,0.1);
    transform: translateX(-100%);
    transition: transform 0.35s var(--transition-smooth);
}
.btn-submit:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.25); }
.btn-submit:hover::after { transform: translateX(0); }

/* ─── LOCATION SECTION ─── */
.location {
    position: relative;
    height: 85vh;
    min-height: 550px;
    overflow: hidden;
    display: flex;
    align-items: center;
}
.location-map-overlay {
    position: absolute;
    inset: 0;
    z-index: 0;
}
#map {
    width: 100%;
    height: 100%;
    filter: grayscale(100%) contrast(1.1) brightness(0.4);
}
.map-tint {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        to right,
        rgba(0,0,0,0.85) 0%,
        rgba(0,0,0,0.6) 40%,
        rgba(0,0,0,0.1) 100%
    );
}
.location-card {
    position: relative;
    z-index: 2;
    padding: 0 5%;
    max-width: 600px;
    color: var(--white);
}
.location-label {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: rgba(255,255,255,0.4);
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}
.location-headline {
    font-family: var(--font-serif);
    font-size: clamp(2.2rem, 4vw, 3.5rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 2rem;
}
.location-address {
    font-size: 1rem;
    color: rgba(255,255,255,0.7);
    line-height: 1.8;
    margin-bottom: 1rem;
}
.location-sub {
    font-size: 0.95rem;
    color: rgba(255,255,255,0.4);
    line-height: 1.7;
    margin-bottom: 2rem;
    font-style: italic;
}

/* ─── FOOTER ─── */
.footer {
    background: var(--black);
    border-top: 1px solid rgba(255,255,255,0.06);
    padding: 3rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.footer-logo {
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}
.footer-logo span { color: #6366f1; }
.footer-copy {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.3);
}

/* ─── SCROLL REVEAL ANIMATIONS ─── */
.reveal-up,
.reveal-left,
.reveal-right {
    opacity: 0;
    transition: opacity 0.9s var(--transition-smooth),
                transform 0.9s var(--transition-smooth);
}
.reveal-up    { transform: translateY(40px); }
.reveal-left  { transform: translateX(-40px); }
.reveal-right { transform: translateX(40px); }

.reveal-up.visible,
.reveal-left.visible,
.reveal-right.visible {
    opacity: 1;
    transform: translate(0, 0);
}

/* ─── KEYFRAMES ─── */
@keyframes fadeUp {
    to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
    to { opacity: 1; }
}
@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; transform: scaleY(1); }
    50% { opacity: 1; transform: scaleY(1.15); }
}

/* ─── RESPONSIVE ─── */
@media (max-width: 900px) {
    .service-block,
    .service-block.reverse {
        grid-template-columns: 1fr;
        direction: ltr;
    }
    .service-block.reverse > * { direction: ltr; }
    .service-image { min-height: 320px; }
    .service-text { padding: 3rem 1.5rem; }
    .contact-inner { grid-template-columns: 1fr; gap: 3rem; }
    .about-stats { gap: 2rem; }
}

@media (max-width: 768px) {
    #navbar { padding: 1rem 4%; }
    .nav-links { display: none; }
    .hero-title { letter-spacing: -0.01em; }
    .footer { flex-direction: column; gap: 1rem; text-align: center; }
    .stat-divider { width: 50px; height: 1px; }
}