:root {
    --primary-color: #3b82f6;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --dark-bg: #1e293b;
    --light-bg: #f8fafc;
    --dark-text: #1e293b;
    --light-text: #f8fafc;
    --border-color: #e2e8f0;
    --sidebar-width: 280px;
    --header-height: 60px;
    --border-radius: 8px;
    --transition-speed: 0.3s;
    
    /* 시계 섹션 변수 */
    --clock-bg-color: #1e293b;
    --clock-text-color: #f8fafc;
    
    /* 업 타이머 섹션 변수 */
    --up-timer-bg-color: #1e293b;
    --up-timer-text-color: #f8fafc;
    
    /* 다운 타이머 섹션 변수 */
    --down-timer-bg-color: #1e293b;
    --down-timer-text-color: #f8fafc;
}

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

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--light-bg);
    color: var(--dark-text);
    line-height: 1.6;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* 사이드바 스타일 */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--dark-bg);
    color: var(--light-text);
    padding: 20px 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    transition: width var(--transition-speed);
    z-index: 100;
}

.sidebar-header {
    padding: 0 20px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.sidebar-menu {
    list-style: none;
    padding: 20px 0;
}

.sidebar-menu li {
    margin-bottom: 5px;
}

.sidebar-menu a {
    display: flex;
    align-items: center;
    padding: 12px 20px;
    color: var(--light-text);
    text-decoration: none;
    transition: background-color var(--transition-speed);
    border-radius: 0;
    position: relative;
}

.sidebar-menu a:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.sidebar-menu a.active {
    background-color: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.sidebar-menu a i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

.sidebar-menu a span {
    flex: 1;
}

/* 토글 스위치 스타일 */
.toggle-switch {
    position: relative;
    display: inline-block;
    width: 40px;
    height: 20px;
    margin-left: 10px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #4a5568;
    transition: var(--transition-speed);
    border-radius: 20px;
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 2px;
    bottom: 2px;
    background-color: #e2e8f0;
    transition: var(--transition-speed);
    border-radius: 50%;
}

input:checked + .toggle-slider {
    background-color: var(--primary-color);
}

input:checked + .toggle-slider:before {
    transform: translateX(20px);
    background-color: white;
}

/* 메인 콘텐츠 스타일 */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 20px;
    transition: margin-left var(--transition-speed);
}

.content-header {
    margin-bottom: 30px;
}

.content-header h1 {
    font-size: 2rem;
    font-weight: 700;
}

/* 섹션 스타일 */
.section {
    display: none;
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    padding: 20px;
    margin-bottom: 20px;
}

.section.active {
    display: block;
}

.section-header {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.section-header h2 {
    font-size: 1.5rem;
    font-weight: 500;
}

/* 폼 스타일 */
.settings-form {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

/* 설정 요소들을 한 줄에 배치 - 공통 스타일 */
.form-group.settings-row {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

/* 설정 옵션 행 (배경색, 글자색, 깜박임, 시표시) */
.form-group.setting-options-row {
    background-color: rgba(255, 255, 255, 0.05);
    padding: 15px;
    border-radius: var(--border-radius);
    justify-content: flex-start;
    gap: 1.5rem;
}

/* 시간 설정 및 버튼 행 */
.form-group.time-settings-row {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 15px;
}

.time-settings-row .timer-input {
    display: flex;
    gap: 10px;
    width: 100%;
    margin-bottom: 5px;
}

.time-settings-row .timer-controls {
    display: flex;
    gap: 10px;
    margin-top: 5px;
    justify-content: center;
}

.form-group.settings-row label {
    margin: 0;
    white-space: nowrap;
}

.form-group.settings-row input[type="color"] {
    width: 40px;
    height: 40px;
    padding: 0;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.form-group.settings-row .toggle-switch {
    margin: 0;
}

.form-group input[type="number"] {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

/* 색상 선택기 스타일 */
input[type="color"] {
    width: 70px;
    height: 40px;
    padding: 0;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    background: none;
}

input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}

input[type="color"]::-webkit-color-swatch {
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

/* 타이머 입력 스타일 */
.timer-input {
    display: flex;
    gap: 10px;
    width: 100%;
}

.timer-input input {
    flex: 1;
    text-align: center;
}

/* 타이머 입력 라벨 스타일 추가 */
.time-labels {
    display: flex;
    width: 100%;
    justify-content: space-between;
    margin-bottom: 5px;
}

.time-labels span {
    flex: 1;
    text-align: center;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--dark-text);
}

/* 시간 입력 필드 유효성 스타일 */
.timer-input input:invalid {
    border-color: var(--danger-color);
    background-color: rgba(239, 68, 68, 0.05);
}

/* 타이머 컨트롤 스타일 */
.timer-controls {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

/* 버튼 스타일 */
.btn {
    display: inline-block;
    padding: 8px 16px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color var(--transition-speed);
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2563eb;
}

.btn-danger {
    background-color: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background-color: #dc2626;
}

#resetButton {
    margin-top: 30px;
}

/* 미리보기 섹션 */
.preview-section {
    background-color: var(--light-bg);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
}

.preview-section h2 {
    color: var(--light-text);
    margin-bottom: 15px;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.preview-section h2::before {
    content: '\f03e';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    color: var(--primary-color);
}

.preview-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
    border-radius: var(--border-radius);
    padding: 30px;
    position: relative;
    overflow: hidden;
}

/* 시계 메뉴 스타일 */
.preview-container[data-section="clock"] {
    background-color: var(--clock-bg-color);
}

.preview-container[data-section="clock"] .timer-time {
    font-size: 100px;
    font-weight: 700;
    line-height: 1;
    color: var(--clock-text-color);
    display: inline-flex;
    align-items: flex-end;
}

.preview-container[data-section="clock"] .timer-seconds {
    font-size: 20px;
    font-weight: 500;
    line-height: 1;
    color: var(--clock-text-color);
    opacity: 0.8;
    margin-left: 5px;
    position: relative;
    top: 30px;
}

/* 업 타이머 메뉴 스타일 */
.preview-container[data-section="up-timer"] {
    background-color: var(--up-timer-bg-color);
}

.preview-container[data-section="up-timer"] .timer-time {
    font-size: 120px;
    font-weight: 700;
    line-height: 1;
    color: var(--up-timer-text-color);
}

.preview-container[data-section="up-timer"] .timer-seconds {
    font-size: 60px;
    font-weight: 500;
    line-height: 1;
    color: var(--up-timer-text-color);
    opacity: 1;
    margin-left: 5px;
}

/* 다운 타이머 메뉴 스타일 */
.preview-container[data-section="down-timer"] {
    background-color: var(--down-timer-bg-color);
}

.preview-container[data-section="down-timer"] .timer-time {
    font-size: 140px;
    font-weight: 700;
    line-height: 1;
    color: var(--down-timer-text-color);
}

.preview-container[data-section="down-timer"] .timer-seconds {
    font-size: 70px;
    font-weight: 500;
    line-height: 1;
    color: var(--down-timer-text-color);
    opacity: 1;
    margin-left: 5px;
}

/* 깜빡임 효과 */
@keyframes blink {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.blink {
    animation: blink 1s infinite;
}

/* 반응형 스타일 */
@media (max-width: 768px) {
    .sidebar {
        width: 0;
        overflow: hidden;
    }
    
    .main-content {
        margin-left: 0;
        padding: 15px;
    }
    
    .container.sidebar-open .sidebar {
        width: var(--sidebar-width);
    }
    
    .container.sidebar-open .main-content {
        margin-left: var(--sidebar-width);
    }
    
    .settings-form {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .preview-container {
        min-height: 200px;
        padding: 20px;
    }
    
    .form-group {
        margin-bottom: 10px;
    }
    
    .timer-input {
        gap: 5px;
    }
    
    .timer-input input {
        padding: 8px;
    }
    
    .timer-controls {
        gap: 5px;
    }
    
    .btn {
        padding: 8px 12px;
        font-size: 0.9rem;
    }
    
    .preview-container[data-section="clock"] .timer-time {
        font-size: 70px;
        display: inline-flex;
        align-items: flex-end;
    }
    
    .preview-container[data-section="clock"] .timer-seconds {
        font-size: 14px;
        position: relative;
        top: 20px;
    }
    
    .preview-container[data-section="up-timer"] .timer-time {
        font-size: 80px;
    }
    
    .preview-container[data-section="up-timer"] .timer-seconds {
        font-size: 40px;
    }
    
    .preview-container[data-section="down-timer"] .timer-time {
        font-size: 90px;
    }
    
    .preview-container[data-section="down-timer"] .timer-seconds {
        font-size: 45px;
    }
    
    .form-group.settings-row {
        gap: 0.5rem;
    }
    
    .form-group.settings-row input[type="color"] {
        width: 30px;
        height: 30px;
    }
    
    .form-group.setting-options-row {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 1rem;
        padding: 10px;
    }
    
    .form-group.setting-options-row label {
        min-width: auto;
    }
    
    .time-labels span {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 10px;
    }
    
    .preview-container {
        min-height: 150px;
        padding: 15px;
    }
    
    .timer-input input {
        padding: 6px;
    }
    
    .btn {
        padding: 6px 10px;
        font-size: 0.8rem;
    }
    
    .preview-container[data-section="clock"] .timer-time {
        font-size: 50px;
        display: inline-flex;
        align-items: flex-end;
    }
    
    .preview-container[data-section="clock"] .timer-seconds {
        font-size: 10px;
        position: relative;
        top: 16px;
    }
    
    .preview-container[data-section="up-timer"] .timer-time {
        font-size: 60px;
    }
    
    .preview-container[data-section="up-timer"] .timer-seconds {
        font-size: 30px;
    }
    
    .preview-container[data-section="down-timer"] .timer-time {
        font-size: 70px;
    }
    
    .preview-container[data-section="down-timer"] .timer-seconds {
        font-size: 35px;
    }
    
    .form-group.settings-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .form-group.settings-row label {
        margin-bottom: 0.25rem;
    }
    
    .form-group.setting-options-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.8rem;
    }
    
    .form-group.setting-options-row label {
        margin-bottom: 0.2rem;
    }
    
    .form-group.setting-options-row .toggle-switch {
        margin-bottom: 0.5rem;
    }
    
    .time-labels span {
        font-size: 0.8rem;
    }
}

/* 사이드바 푸터 */
.sidebar-footer {
    margin-top: auto;
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.btn-block {
    display: block;
    width: 100%;
    text-align: center;
}