:root {
    --bg-primary: #080a0f;
    --bg-secondary: #11141d;
    --accent-color: #38bdf8;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --positive: #00e699;
    --negative: #ff4d4d;
    --card-bg: #11141d;
    --border-color: #222834;
    --glass: rgba(255, 255, 255, 0.03);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Pretendard', sans-serif; }
body { background-color: var(--bg-primary); color: var(--text-primary); height: 100vh; overflow: hidden; }

.app-container { display: flex; height: 100vh; }

/* 사이드바 */
.sidebar { width: 280px; background-color: var(--bg-secondary); border-right: 1px solid var(--border-color); padding: 1.5rem; display: flex; flex-direction: column; }
.logo { display: flex; align-items: center; gap: 0.75rem; font-size: 1.5rem; font-weight: 800; color: var(--accent-color); margin-bottom: 3rem; }
.nav-section { margin-bottom: 2.5rem; }
.nav-label { font-size: 0.7rem; font-weight: 800; color: #475569; text-transform: uppercase; margin-bottom: 1rem; padding-left: 0.5rem; }
nav ul { list-style: none; }
nav li { padding: 0.8rem 1rem; border-radius: 0.75rem; cursor: pointer; color: var(--text-secondary); display: flex; align-items: center; gap: 0.75rem; transition: 0.3s; margin-bottom: 0.25rem; font-weight: 600; }
nav li:hover { background: var(--glass); color: white; }
nav li.active { background: linear-gradient(90deg, var(--accent-color), #0ea5e9); color: white; box-shadow: 0 4px 15px rgba(56, 189, 248, 0.2); }

/* 메인 콘텐츠 */
.main-content { flex: 1; display: flex; flex-direction: column; overflow-y: auto; background: radial-gradient(circle at top right, #111827, #080a0f); }
header { padding: 2rem 3rem; }
.search-bar { background: var(--glass); border: 1px solid var(--border-color); border-radius: 1.25rem; padding: 1rem 1.5rem; display: flex; align-items: center; gap: 1rem; backdrop-filter: blur(10px); }
.search-bar input { background: none; border: none; outline: none; color: white; width: 100%; font-size: 1.1rem; }

.dashboard { padding: 0 3rem 3rem 3rem; flex: 1; }
.view-content { animation: fadeIn 0.4s ease-out; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.hidden { display: none !important; }

/* 세련된 기간 선택기 (Period Selector) */
.period-selector {
    display: flex;
    background: #080a0f;
    padding: 0.3rem;
    border-radius: 50px;
    border: 1px solid var(--border-color);
    gap: 0.2rem;
}

.period-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.5rem 1.2rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.period-btn:hover { color: white; }

.period-btn.active {
    background: linear-gradient(135deg, #38bdf8 0%, #0ea5e9 100%);
    color: white;
    box-shadow: 0 2px 10px rgba(56, 189, 248, 0.4);
}

/* 시장 현황 그리드 */
.market-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; margin-top: 2rem; }
.asset-card { background: var(--glass); border: 1px solid var(--border-color); border-radius: 1.5rem; padding: 1.5rem; cursor: pointer; transition: 0.3s; }
.asset-card:hover { transform: translateY(-5px); border-color: var(--accent-color); background: rgba(56, 189, 248, 0.05); }
.card-top { display: flex; justify-content: space-between; margin-bottom: 1rem; }
.card-price { font-size: 1.5rem; font-weight: 800; }

/* 상세 페이지 */
.asset-header { display: flex; justify-content: space-between; margin-bottom: 2rem; }
.price { font-size: 4rem; font-weight: 900; letter-spacing: -0.03em; }
.chart-section { background: var(--bg-secondary); border: 1px solid var(--border-color); border-radius: 2rem; padding: 2rem; margin-bottom: 2.5rem; height: 550px; }
.chart-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 2rem; }

.insight-card { background: var(--glass); border: 1px solid var(--border-color); border-radius: 2rem; padding: 2.5rem; }
.stat-item { background: var(--glass); border: 1px solid var(--border-color); border-radius: 1.5rem; padding: 1.5rem; margin-bottom: 1rem; }
.stat-item.highlight { border-left: 5px solid var(--accent-color); background: linear-gradient(90deg, rgba(56, 189, 248, 0.1), transparent); }

.welcome-hero h1 { font-size: 4rem; font-weight: 900; margin-bottom: 1.5rem; background: linear-gradient(to bottom, #fff, #94a3b8); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.quick-tags { display: flex; gap: 1rem; justify-content: center; margin-top: 2.5rem; }
.quick-tags span { background: var(--glass); border: 1px solid var(--border-color); padding: 0.75rem 1.5rem; border-radius: 50px; font-size: 0.95rem; cursor: pointer; transition: 0.3s; }
.quick-tags span:hover { background: var(--accent-color); color: white; transform: scale(1.05); }