@import url('https://fonts.googleapis.com/css2?family=Pretendard:wght@400;700;900&display=swap');

:root {
    --bg-dark: #0f172a;
    --card-bg: #1e293b;
    --primary-neon: #10b981;
    --secondary-neon: #3b82f6;
    --accent-pink: #f43f5e;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --white: #ffffff;
    --header-bg: rgba(15, 23, 42, 0.8);
    --footer-bg: #0b1120;
    --hero-bg: radial-gradient(circle at center, #1e293b 0%, #0f172a 100%);
    --border-color: rgba(255, 255, 255, 0.05);
    --scrollbar-track: #0f172a;
    --scrollbar-thumb: #1e293b;
}

[data-theme="light"] {
    --bg-dark: #f1f5f9;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --white: #0f172a;
    --header-bg: rgba(241, 245, 249, 0.85);
    --footer-bg: #e2e8f0;
    --hero-bg: radial-gradient(circle at center, #e2e8f0 0%, #f1f5f9 100%);
    --border-color: rgba(0, 0, 0, 0.07);
    --scrollbar-track: #f1f5f9;
    --scrollbar-thumb: #cbd5e1;
}

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

body {
    font-family: 'Pretendard', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
}
::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary-neon);
}

header {
    padding: 1.5rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--header-bg);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.8rem;
    font-weight: 900;
    background: linear-gradient(to right, var(--primary-neon), var(--secondary-neon));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.9rem;
    text-transform: uppercase;
    transition: 0.3s;
}

nav ul li a:hover {
    color: var(--primary-neon);
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 10%;
    background: var(--hero-bg);
}

.hero h1 {
    font-size: clamp(3rem, 10vw, 6rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -2px;
}

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

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 2.5rem;
}

.btn-main {
    background: var(--primary-neon);
    color: var(--bg-dark);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 800;
    font-size: 1.1rem;
    transition: 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 10px 20px rgba(16, 185, 129, 0.3);
}

.btn-main:hover {
    transform: scale(1.05) translateY(-5px);
    box-shadow: 0 15px 30px rgba(16, 185, 129, 0.4);
}

/* Risks Section */
.section-padding {
    padding: 8rem 5%;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 900;
    text-align: center;
    margin-bottom: 4rem;
}

.grid-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.card {
    background: var(--card-bg);
    padding: 3rem 2rem;
    border-radius: 24px;
    transition: 0.4s;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--secondary-neon);
    opacity: 0;
    transition: 0.3s;
}

.card:hover {
    transform: translateY(-10px);
    border-color: rgba(59, 130, 246, 0.3);
}

.card:hover::before {
    opacity: 1;
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--white);
}

.card p {
    color: var(--text-muted);
}

/* Footer */
footer {
    padding: 5rem 5%;
    background: var(--footer-bg);
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 900;
    margin-bottom: 2rem;
    display: inline-block;
    color: var(--primary-neon);
}

.contact-box {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 20px;
    display: inline-block;
    margin-bottom: 3rem;
}

.contact-box p {
    font-weight: 700;
    font-size: 1.2rem;
}

.contact-box span {
    color: var(--primary-neon);
    font-size: 1.5rem;
    display: block;
    margin-top: 0.5rem;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
}

.copy {
    color: #475569;
    font-size: 0.8rem;
}

.theme-toggle {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 50px;
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-size: 1.2rem;
    transition: 0.3s;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--text-main);
}

.theme-toggle:hover {
    border-color: var(--primary-neon);
    box-shadow: 0 0 12px rgba(16, 185, 129, 0.25);
}

@media (max-width: 768px) {
    .hero h1 { font-size: 3rem; }
    nav ul { display: none; }
    .section-padding { padding: 5rem 5%; }
}