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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Malgun Gothic', sans-serif;
    background: #f8f7fa;
    min-height: 100vh;
    padding: 60px 20px;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    background: white;
    padding: 50px;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
}

/* 헤더 레이아웃 */
.header {
    margin-bottom: 40px;
}

.header h1 {
    font-size: 36px;
    margin-bottom: 12px;
    color: #1f2937;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 12px;
}

.header h1 .logo {
    width: 44px;
    height: 44px;
    object-fit: contain;
    flex-shrink: 0;
}

h1 {
    font-size: 36px;
    margin-bottom: 12px;
    color: #1f2937;
    font-weight: 700;
}

.subtitle {
    color: #6b7280;
    margin-bottom: 40px;
    font-size: 15px;
    line-height: 1.6;
}

.section {
    margin-bottom: 40px;
    background: #f9fafb;
    padding: 30px;
    border-radius: 16px;
    border: 1px solid #e5e7eb;
    transition: all 0.3s ease;
}

.section:hover {
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.08);
    border-color: #c7d2fe;
}

.section-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #1a1a1a;
    display: flex;
    align-items: center;
}

.section-number {
    background: #6366f1;
    color: white;
    width: 32px;
    height: 32px;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    font-weight: 600;
    margin-right: 12px;
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3);
}

/* 고정 확장자 체크박스 */
.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.checkbox-item {
    display: flex;
    align-items: center;
}

.checkbox-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 10px;
    cursor: pointer;
    accent-color: #6366f1;
}

.checkbox-item label {
    cursor: pointer;
    user-select: none;
    font-size: 15px;
    color: #374151;
    font-weight: 500;
}

/* 커스텀 확장자 입력 */
.input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.input-group input[type="text"] {
    flex: 1;
    padding: 14px 18px;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: white;
}

.input-group input[type="text"]:focus {
    outline: none;
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.btn-add {
    padding: 14px 28px;
    background: #6366f1;
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.btn-add:hover {
    background: #4f46e5;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

/* 커스텀 확장자 표시 영역 */
.extensions-box {
    border: 2px solid #e5e7eb;
    border-radius: 16px;
    padding: 20px;
    min-height: 240px;
    max-height: 400px;
    background: white;
    position: relative;
    margin-top: 20px;
    overflow: hidden;
}

.extensions-count {
    position: absolute;
    top: 16px;
    left: 16px;
    font-size: 14px;
    color: #6b7280;
    font-weight: 600;
    background: #f3f4f6;
    padding: 6px 12px;
    border-radius: 8px;
    z-index: 10;
}

.extensions-list {
    margin-top: 50px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    max-height: 300px;
    overflow-y: auto;
    padding-right: 8px;
}

/* 스크롤바 스타일링 */
.extensions-list::-webkit-scrollbar {
    width: 8px;
}

.extensions-list::-webkit-scrollbar-track {
    background: #f3f4f6;
    border-radius: 10px;
}

.extensions-list::-webkit-scrollbar-thumb {
    background: #c7d2fe;
    border-radius: 10px;
}

.extensions-list::-webkit-scrollbar-thumb:hover {
    background: #a5b4fc;
}

.extension-tag {
    display: inline-flex;
    align-items: center;
    background: #eef2ff;
    border: 1.5px solid #c7d2fe;
    border-radius: 12px;
    padding: 10px 14px;
    font-size: 14px;
    font-weight: 600;
    color: #6366f1;
    transition: all 0.2s ease;
}

.extension-tag:hover {
    transform: translateY(-1px);
    background: #e0e7ff;
    border-color: #a5b4fc;
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.15);
}

.extension-tag .name {
    margin-right: 10px;
}

.extension-tag .btn-remove {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    color: #9ca3af;
    padding: 0;
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.extension-tag .btn-remove:hover {
    color: #ef4444;
    transform: scale(1.2);
}

.empty-message {
    color: #9ca3af;
    text-align: center;
    margin-top: 80px;
    font-size: 15px;
    font-weight: 500;
}

.error-message {
    color: #ef4444;
    font-size: 14px;
    margin-top: 8px;
    display: none;
    padding: 8px 12px;
    background: #fef2f2;
    border-radius: 8px;
    border-left: 3px solid #ef4444;
}

.error-message.show {
    display: block;
}

/* 토스트 메시지 */
.toast {
    position: fixed;
    top: 40px;
    left: 50%;
    transform: translateX(-50%) translateY(-30px);
    background: white;
    color: #1a1a1a;
    padding: 18px 28px;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    font-size: 15px;
    font-weight: 600;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.4s ease, transform 0.4s ease;
    pointer-events: none;
    max-width: 400px;
    border: 2px solid #e5e7eb;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.toast.success {
    background: #10b981;
    color: white;
    border-color: #10b981;
}

.toast.success-unblock {
    background: #f97316;
    color: white;
    border-color: #f97316;
}

.toast.error {
    background: #ef4444;
    color: white;
    border-color: #ef4444;
}

.toast.info {
    background: #6366f1;
    color: white;
    border-color: #6366f1;
}