:root {
    --main-color: #00ff88;
    --main-hover: #00cc6d;
    --bg-dark: #0a0c10;
    --bg-card: #151921;
    --text-muted: #94a3b8;
    --header-bg: rgba(10, 12, 16, 0.85);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
    background: var(--bg-dark);
    color: #f8fafc;
    line-height: 1.7; /* Slightly more breathable line height */
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased; /* Sharper fonts on Mac */
}

/* Updated List Styles */
ul.tech-list {
    list-style: none;
    padding: 0;
}

ul.tech-list li {
    margin-bottom: 12px;
    padding-left: 28px;
    position: relative;
    color: var(--text-muted);
    font-size: 15px;
}

ul.tech-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--main-color);
    font-weight: 800;
}

/* Refined Badge/Tag Style */
.badge {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(0, 255, 136, 0.1);
    border: 1px solid rgba(0, 255, 136, 0.3);
    color: var(--main-color);
    font-size: 12px;
    font-weight: 600;
    border-radius: 20px;
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* HEADER */

header {
    position: fixed;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 60px;
    z-index: 100;
    transition: all 0.4s ease;
    backdrop-filter: blur(10px);
}

header.scrolled {
    padding: 15px 60px;
    background: var(--header-bg);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.logo {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -1px;
    color: var(--main-color);
}

header nav a {
    margin-left: 30px;
    text-decoration: none;
    color: #cbd5e1;
    font-size: 15px;
    font-weight: 500;
    transition: 0.3s;
}

header nav a:hover {
    color: var(--main-color);
}

/* HERO */

.hero {
    height: 100vh;
    background: radial-gradient(circle at top right, #002e1c, transparent), 
                radial-gradient(circle at bottom left, #0a0c10, #0a0c10);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 900px;
    padding: 0 20px;
}

.hero h1 {
    font-size: clamp(40px, 8vw, 72px);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 20px;
    letter-spacing: -2px;
}

.hero h1 span {
    color: var(--main-color);
    display: block;
}

.hero p {
    font-size: clamp(16px, 2vw, 20px);
    margin-bottom: 40px;
    color: var(--text-muted);
    font-weight: 400;
}

.btn {
    display: inline-block;
    padding: 16px 40px;
    background: var(--main-color);
    color: #000;
    text-decoration: none;
    font-weight: 700;
    border-radius: 4px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn:hover {
    background: var(--main-hover);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 255, 136, 0.2);
}

/* ICON SYSTEM */

.icon-wrap {
    display: flex;
    justify-content: center;
    margin-top: 60px;
    gap: 30px;
    flex-wrap: wrap;
}

.icon-box {
    text-align: center;
    transition: 0.3s;
}

.icon-circle {
    width: 70px;
    height: 70px;
    border-radius: 16px;
    background: rgba(0, 255, 136, 0.05);
    border: 1px solid rgba(0, 255, 136, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    transition: 0.4s;
}

.icon-circle svg {
    width: 30px;
    height: 30px;
    stroke: var(--main-color);
    stroke-width: 1.5;
}

.icon-box:hover .icon-circle {
    background: var(--main-color);
    transform: rotate(-5deg) translateY(-5px);
}

.icon-box:hover svg {
    stroke: #000;
}

.icon-box span {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-muted);
}

/* SECTIONS */

.sub-hero {
    padding: 180px 20px 100px;
    text-align: center;
    background: linear-gradient(to bottom, #0f1218, #0a0c10);
}

.sub-hero h1 {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 10px;
}

.content {
    padding: 120px 20px;
}

.content.alt {
    background: #0d1117;
}

.container {
    max-width: 1100px;
    margin: auto;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 40px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 40px;
    height: 4px;
    background: var(--main-color);
}

/* GRIDS & CARDS */

.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: var(--bg-card);
    padding: 0;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.03);
    transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    height: 100%;
    overflow: visible;
}

.card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.card:hover {
    transform: translateY(-10px);
    border-color: rgba(0, 255, 136, 0.3);
    background: #1a1f29;
}

.card:hover .card-image img {
    transform: scale(1.1);
}

.card h3 {
    font-size: 22px;
    margin: 25px 30px 15px;
    color: #fff;
}

.card p {
    color: var(--text-muted);
    font-size: 15px;
    padding: 0 30px 30px;
}

.card .icon-circle {
    margin: -35px 30px 0;
    position: relative;
    z-index: 2;
    background: var(--bg-card);
}

/* REVEAL ANIMATION */

.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: 1.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

/* FOOTER */

footer {
    background: #050608;
    color: var(--text-muted);
    padding: 80px 20px 40px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: 60px;
    max-width: 1100px;
    margin: 0 auto 60px;
}

.footer-content strong {
    font-size: 18px;
    color: #fff;
    display: block;
    margin-bottom: 15px;
}

.footer-info {
    font-size: 14px;
    line-height: 2;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding-top: 30px;
    text-align: center;
    font-size: 13px;
    color: #475569;
}

/* RESPONSIVE */

@media (max-width: 900px) {
    header {
        padding: 20px 30px;
    }
    
    .two-col {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 40px;
    }
}