:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --bg-main: #f8fafc;
    --bg-sidebar: #1e293b;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --white: #ffffff;
    --border: #e2e8f0;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --card-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    overflow: hidden;
}

#app {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--bg-sidebar);
    color: var(--white);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 2.5rem;
}

.logo i {
    color: var(--primary);
}

nav {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1rem;
    border-radius: 0.5rem;
    border: none;
    background: transparent;
    color: #94a3b8;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.95rem;
    text-align: left;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--white);
}

.nav-item.active {
    background: var(--primary);
    color: var(--white);
}

.sidebar-footer {
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.8rem;
    color: #94a3b8;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.dot.online { background-color: var(--success); }

/* Main Content */
.content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.content-header {
    height: 64px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
}

.content-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.avatar {
    width: 32px;
    height: 32px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

#view-container {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

/* Common Card Style */
.card {
    background: var(--white);
    border-radius: 1rem;
    border: 1px solid var(--border);
    box-shadow: var(--card-shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Utilities */
.grid { display: grid; gap: 1.5rem; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.flex { display: flex; gap: 1rem; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }

button.btn-primary {
    background: var(--primary);
    color: var(--white);
    border: none;
    padding: 0.625rem 1.25rem;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
}

button.btn-primary:hover { background: var(--primary-dark); }

input {
    padding: 0.625rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    outline: none;
    transition: border-color 0.2s;
}

input:focus { border-color: var(--primary); }