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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 800px;
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5em;
}

.add-link-section {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.add-link-section input {
    flex: 1;
    min-width: 200px;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.add-link-section input:focus {
    outline: none;
    border-color: #667eea;
}

.add-link-section button {
    padding: 12px 30px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
}

.add-link-section button:hover {
    background: #5568d3;
}

.links-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 15px;
}

.link-card {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 12px;
    border: 2px solid #e0e0e0;
    transition: all 0.3s;
    cursor: grab;
    position: relative;
}

.link-card:active {
    cursor: grabbing;
}

.link-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.link-card h3 {
    color: #333;
    margin-bottom: 8px;
    font-size: 1.1em;
    word-break: break-word;
}

.link-card p {
    color: #666;
    font-size: 0.85em;
    word-break: break-all;
    margin-bottom: 10px;
}

.delete-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: #ff4757;
    color: white;
    border: none;
    border-radius: 50%;
    width: 28px;
    height: 28px;
    cursor: pointer;
    font-size: 16px;
    line-height: 1;
    transition: background 0.3s;
}

.delete-btn:hover {
    background: #ff3838;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #999;
}

.empty-state p {
    font-size: 1.2em;
    margin-bottom: 10px;
}

.empty-state small {
    font-size: 0.9em;
}

/* 드래그 앤 드롭 스타일 */
.link-card.dragging {
    opacity: 0.5;
    transform: scale(0.95);
}

.link-card.drag-over {
    border-color: #667eea;
    background: #e8ecff;
    transform: scale(1.05);
}