:root {
    --bg-color: #0a0a0a;
    --card-bg: #151515;
    --text-primary: #f0f0f0;
    --text-secondary: #888888;
    --accent-red: #d32f2f;
    --accent-blue: #1976d2;
    --accent-orange: #f59e0b;
}

body, html {
    margin: 0;
    padding: 0;
    font-family: 'Pretendard', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow-x: hidden;
    scroll-behavior: smooth;
}

/* 공통 섹션 스타일 */
section {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 4rem 20px;
    text-align: center;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 1s ease-out, transform 1s ease-out;
}

section.visible {
    opacity: 1;
    transform: translateY(0);
}

h1 {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 800;
    margin-bottom: 10px;
    letter-spacing: -2px;
    background: linear-gradient(90deg, #fff, #888);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

h2 {
    font-size: clamp(1.8rem, 5vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--accent-red);
}

p {
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--text-secondary);
    max-width: 800px;
    word-break: keep-all;
    margin-left: auto;
    margin-right: auto;
}

/* 1. Hero Section */
#hero {
    background: radial-gradient(circle at center, #1a1a1a 0%, #000000 100%);
    position: relative;
}

.badge {
    background: var(--accent-red);
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    color: #ccc;
    margin-top: 10px;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* 2. Data Section (Calendar & Slider) */
#data {
    padding-top: 6rem;
}

#calendar-container {
    display: flex;
    justify-content: center;
    margin: 3rem 0;
    position: relative;
}

dynamic-calendar {
    filter: drop-shadow(0 0 40px rgba(0,0,0,0.8));
    transition: transform 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

#slider-outer-container {
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
}

#slider-container {
    background: #151515;
    padding: 2.5rem;
    border-radius: 20px;
    border: 1px solid #333;
}

.slider {
    width: 100%;
    height: 6px;
    border-radius: 5px;
    background: #333;
    outline: none;
    appearance: none;
}

.slider::-webkit-slider-thumb {
    appearance: none;
    width: 24px;
    height: 24px;
    background: var(--accent-red);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 15px var(--accent-red);
    border: 2px solid white;
}

#slider-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

#current-year-display {
    color: white;
    font-weight: bold;
    font-size: 1rem;
}

.data-insight {
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(211, 47, 47, 0.1);
    border-radius: 8px;
    border-left: 3px solid var(--accent-red);
}

.highlight-red { color: var(--accent-red); font-weight: bold; }

/* 3. Infrastructure & Trade Sections */
.warning-box {
    margin-top: 2rem;
    padding: 1rem 2rem;
    border: 1px solid var(--accent-red);
    color: var(--accent-red);
    font-size: 0.9rem;
    font-weight: bold;
    border-radius: 4px;
}

/* 4. Outro Section & Cards */
.card-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    margin-top: 40px;
}

.card {
    background: #151515;
    padding: 30px;
    border-radius: 12px;
    border: 1px solid #333;
    max-width: 350px;
    text-align: left;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-10px);
}

.card h3 {
    color: #fff;
    margin-top: 0;
    margin-bottom: 1rem;
}

footer {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
    font-size: 0.8rem;
    background: #000;
}

/* Responsive Design */
@media (max-width: 768px) {
    p { font-size: 1rem; }
    h1 { font-size: 3rem; }
    h2 { font-size: 1.8rem; }
}