/* ========================================
   공통 스타일
   ======================================== */

:root {
    --primary-color: #3498db;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --info-color: #3498db;
    --secondary-color: #95a5a6;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --border-color: #e0e0e0;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-color);
}

/* ========================================
   타이포그래피
   ======================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

h1 { font-size: 1.75rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.1rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.9rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #2980b9;
}

/* ========================================
   유틸리티 클래스
   ======================================== */

.text-muted {
    color: var(--text-secondary) !important;
}

.text-primary {
    color: var(--primary-color) !important;
}

.text-success {
    color: var(--success-color) !important;
}

.text-danger {
    color: var(--danger-color) !important;
}

.text-warning {
    color: var(--warning-color) !important;
}

.bg-light-gray {
    background-color: var(--bg-color);
}

.cursor-pointer {
    cursor: pointer;
}

/* ========================================
   Alert 컨테이너
   ======================================== */

.alert-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
    max-width: 400px;
}

.alert {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    margin-bottom: 10px;
}

/* ========================================
   로딩 스피너
   ======================================== */

.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
}

.loading-overlay .spinner-border {
    width: 3rem;
    height: 3rem;
}

/* ========================================
   반응형 유틸리티
   ======================================== */

@media (max-width: 1024px) {
    body {
        font-size: 15px;
    }
}

@media (max-width: 768px) {
    body {
        font-size: 14px;
    }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.3rem; }
    h3 { font-size: 1.15rem; }
}