:root {
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-color: #111827;
    --border-color: #f3f4f6;
    --sub-text: #6b7280;

    /* 통신사 배지 색상 (라이트모드) */
    --skt-color: #dc2626; --skt-bg: #fef2f2;
    --kt-color: #2563eb; --kt-bg: #eff6ff;
    --lgu-color: #db2777; --lgu-bg: #fdf2f8;
    --comp-color: #4f46e5; --comp-bg: #e0e7ff;
}

html[data-theme="dark"] {
    --bg-color: #111827;
    --card-bg: #1f2937;
    --text-color: #ffffff;
    --border-color: #374151;
    --sub-text: #9ca3af;

    /* 통신사 배지 색상 (다크모드) */
    --skt-color: #fca5a5; --skt-bg: rgba(220, 38, 38, 0.2);
    --kt-color: #93c5fd; --kt-bg: rgba(37, 99, 235, 0.2);
    --lgu-color: #fbcfe8; --lgu-bg: rgba(219, 39, 119, 0.2);
    --comp-color: #c7d2fe; --comp-bg: rgba(79, 70, 229, 0.2);
}

body { 
    font-family: 'Pretendard', -apple-system, sans-serif;
    /* 기본 폰트 최적화 자간 배율 조정 */
    letter-spacing: -0.02em; 
    background-color: var(--bg-color); 
    color: var(--text-color);
    margin: 0; 
    padding-bottom: 6rem; 
    min-height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

.container { 
    max-width: 28rem; 
    margin: 0 auto; 
    padding: 0 1rem; 
}

.header { 
    display: flex; 
    justify-content: space-between; 
    align-items: start; 
    padding: 2rem 0; 
}

.header h1 { 
    font-size: 1.5rem; 
    font-weight: 800; 
    margin: 0; 
    letter-spacing: -0.025em; 
}

.header p { 
    font-size: 0.875rem; 
    color: var(--sub-text); 
    margin: 0.25rem 0 0 0; 
}

.theme-btn {
    padding: 0.5rem; 
    border-radius: 0.75rem; 
    background: var(--card-bg);
    border: 1px solid var(--border-color); 
    color: var(--sub-text); 
    cursor: pointer;
    transition: transform 0.1s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-btn:active { 
    transform: scale(0.95); 
}

.hidden { 
    display: none !important; 
}

.sticky-header {
    position: sticky; 
    top: 0; 
    z-index: 30; 
    padding-bottom: 1rem; 
    margin: 0 -1rem 1.5rem -1rem; 
    padding-left: 1rem; 
    padding-right: 1rem;
    background-color: rgba(249, 250, 251, 0.95); 
    backdrop-filter: blur(8px);
}

html[data-theme="dark"] .sticky-header { 
    background-color: rgba(17, 24, 39, 0.95); 
}

.search-box { 
    position: relative; 
    display: flex; 
    align-items: center; 
    margin-top: 0.5rem; 
}

.search-input {
    width: 100%; 
    padding: 1rem 3rem 1rem 1.25rem; 
    border-radius: 1rem;
    border: 1px solid var(--border-color); 
    background: var(--card-bg); 
    color: var(--text-color);
    font-size: 1.125rem; 
    outline: none; 
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
    transition: all 0.2s; 
    box-sizing: border-box;
}

.search-input:focus { 
    border-color: #3b82f6; 
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.5); 
}

.clear-btn {
    position: absolute; 
    right: 1rem; 
    background: none; 
    border: none; 
    padding: 0.25rem;
    color: #9ca3af; 
    cursor: pointer; 
    display: flex; 
    align-items: center;
}

.clear-btn:hover { 
    color: var(--text-color); 
}

.filter-container { 
    display: flex; 
    gap: 0.5rem; 
    overflow-x: auto; 
    padding-bottom: 0.25rem; 
    margin-top: 0.75rem; 
}

.filter-container::-webkit-scrollbar { 
    display: none; 
}

.filter-container { 
    -ms-overflow-style: none; 
    scrollbar-width: none; 
}

.filter-btn {
    white-space: nowrap; 
    padding: 0.375rem 1rem; 
    border-radius: 9999px;
    border: 1px solid var(--border-color); 
    background: var(--card-bg);
    font-size: 0.875rem; 
    font-weight: 600; 
    color: var(--sub-text); 
    cursor: pointer;
}

.filter-btn.active { 
    background-color: #3b82f6 !important; 
    color: white !important; 
    border-color: #3b82f6 !important; 
}

.card {
    background: var(--card-bg); 
    padding: 1.25rem; 
    border-radius: 1rem;
    border: 1px solid var(--border-color); 
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    margin-bottom: 0.75rem; 
    cursor: pointer; 
    transition: all 0.2s;
}

.card:hover { 
    border-color: #3b82f6; 
}

.card:active { 
    transform: scale(0.98); 
}

.card-top { 
    display: flex; 
    justify-content: space-between; 
    align-items: start; 
    margin-bottom: 0.5rem; 
}

.comp-badge { 
    font-size: 10px; 
    font-weight: bold; 
    padding: 0.125rem 0.5rem; 
    background: var(--border-color); 
    color: var(--sub-text); 
    border-radius: 0.25rem; 
    text-transform: uppercase; 
}

.net-badges { 
    display: flex; 
    gap: 0.25rem; 
}

.net-badge { 
    font-size: 10px; 
    font-weight: bold; 
    padding: 0.125rem 0.375rem; 
    border-radius: 0.25rem; 
}

.net-badge.skt { color: var(--skt-color); background: var(--skt-bg); }
.net-badge.kt { color: var(--kt-color); background: var(--kt-bg); }
.net-badge.lgu { color: var(--lgu-color); background: var(--lgu-bg); }
.net-badge.compare { color: var(--comp-color); background: var(--comp-bg); }

.card-bottom { 
    display: flex; 
    justify-content: space-between; 
    align-items: end; 
}

.card-bottom h3 { 
    font-size: 1.125rem; 
    font-weight: bold; 
    margin: 0; 
}

.link-text { 
    color: #3b82f6; 
    font-size: 11px; 
    font-weight: bold; 
}

.animate-pulse { 
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite; 
}

@keyframes pulse { 
    0%, 100% { opacity: 1; } 
    50% { opacity: .5; } 
}

.skeleton { 
    height: 6rem; 
    background-color: var(--border-color); 
    border-radius: 1rem; 
    margin-bottom: 0.75rem; 
}

.floating-btn {
    position: fixed; 
    bottom: 2rem; 
    right: 1.5rem; 
    z-index: 50; 
    display: flex; 
    align-items: center;
}

.floating-link {
    display: flex; 
    align-items: center; 
    justify-content: center; 
    width: 3.5rem; 
    height: 3.5rem;
    background-color: #3b82f6; 
    color: white; 
    border-radius: 9999px; 
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.3);
    transition: all 0.2s; 
    text-decoration: none;
}

.floating-link:hover { 
    transform: scale(1.1); 
    background-color: #2563eb; 
}

.floating-link:active { 
    transform: scale(0.95); 
}