/* CSS 변수 - 라이트 모드 */
:root {
    --bg-primary: #f5f7fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e8ecf1;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #8888a0;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --accent-light: #e0e7ff;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --border: #e2e8f0;
    --shadow: rgba(0, 0, 0, 0.1);
}

/* 다크 모드 */
[data-theme="dark"] {
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #252542;
    --text-primary: #e8e8f0;
    --text-secondary: #b8b8d0;
    --text-muted: #6868a0;
    --accent: #6366f1;
    --accent-hover: #818cf8;
    --accent-light: #312e81;
    --border: #2a2a4a;
    --shadow: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

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

/* 사이드바 */
.sidebar {
    width: 260px;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 20px;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.logo {
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 20px;
}

.logo h2 {
    color: var(--accent);
    font-size: 1.5rem;
}

.nav-menu {
    list-style: none;
    flex: 1;
}

.nav-item {
    padding: 12px 16px;
    margin-bottom: 8px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-secondary);
    transition: all 0.2s;
}

.nav-item:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-item.active {
    background-color: var(--accent-light);
    color: var(--accent);
    font-weight: 600;
}

.nav-item .icon {
    font-size: 1.2rem;
}

.theme-toggle {
    padding-top: 20px;
    border-top: 1px solid var(--border);
}

.theme-toggle button {
    width: 100%;
    padding: 10px;
    border: none;
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}

.theme-toggle button:hover {
    background-color: var(--accent);
    color: white;
}

/* 메인 콘텐츠 */
.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 40px;
    min-height: 100vh;
}

.section {
    display: none;
    animation: fadeIn 0.3s ease;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

h1 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

h2 {
    font-size: 1.5rem;
    margin: 30px 0 20px;
    color: var(--text-primary);
}

.intro {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

/* 카드 그리드 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 24px;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.2s;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px var(--shadow);
    border-color: var(--accent);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.card h3 {
    color: var(--text-primary);
    margin-bottom: 8px;
}

.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* 로드맵 */
.roadmap {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 30px;
    border: 1px solid var(--border);
    margin-bottom: 30px;
}

.roadmap-tree {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.roadmap-node {
    background-color: var(--bg-tertiary);
    padding: 16px 24px;
    border-radius: 10px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    border: 2px solid transparent;
}

.roadmap-node:hover {
    border-color: var(--accent);
    transform: scale(1.02);
}

.roadmap-node.main {
    background-color: var(--accent);
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
}

.roadmap-node small {
    display: block;
    margin-top: 4px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.roadmap-branches {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.branch {
    position: relative;
}

/* 버튼 스타일 */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}

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

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

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

.btn.danger:hover {
    opacity: 0.9;
}

/* 개념 학습 */
.concept-categories {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.category-btn {
    padding: 10px 20px;
    border: 1px solid var(--border);
    border-radius: 20px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.category-btn:hover,
.category-btn.active {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
}

.concept-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.concept-card {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.2s;
}

.concept-card:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 15px var(--shadow);
}

.concept-card h3 {
    color: var(--accent);
    margin-bottom: 8px;
}

.concept-card .category-tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--accent-light);
    color: var(--accent);
    border-radius: 12px;
    font-size: 0.8rem;
    margin-bottom: 10px;
}

.concept-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.concept-card .learned-badge {
    display: inline-block;
    padding: 4px 8px;
    background-color: var(--success);
    color: white;
    border-radius: 4px;
    font-size: 0.75rem;
    margin-top: 10px;
}

/* 개념 상세 */
.concept-detail {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 30px;
    border: 1px solid var(--border);
}

.concept-detail.hidden {
    display: none;
}

.concept-detail h2 {
    color: var(--accent);
    margin-top: 0;
}

.concept-detail .back-btn {
    margin-bottom: 20px;
    padding: 8px 16px;
    background-color: var(--bg-tertiary);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    color: var(--text-secondary);
}

.concept-detail .back-btn:hover {
    background-color: var(--accent-light);
    color: var(--accent);
}

.concept-section {
    margin-bottom: 24px;
}

.concept-section h3 {
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--accent-light);
}

.concept-section ul {
    margin-left: 20px;
    color: var(--text-secondary);
}

.concept-section li {
    margin-bottom: 8px;
}

.formula-box {
    background-color: var(--bg-tertiary);
    padding: 16px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    overflow-x: auto;
    margin: 10px 0;
}

.example-box {
    background-color: var(--accent-light);
    padding: 16px;
    border-radius: 8px;
    border-left: 4px solid var(--accent);
    margin: 10px 0;
}

/* 퀴즈 */
.quiz-start {
    text-align: center;
    padding: 40px;
}

.quiz-categories {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 30px;
}

.quiz-cat-btn {
    padding: 15px 30px;
    border: 2px solid var(--border);
    border-radius: 10px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s;
}

.quiz-cat-btn:hover {
    border-color: var(--accent);
    background-color: var(--accent);
    color: white;
}

.quiz-area {
    max-width: 700px;
    margin: 0 auto;
}

.quiz-area.hidden,
.quiz-result.hidden {
    display: none;
}

.quiz-progress {
    margin-bottom: 30px;
}

#quizProgressText {
    display: block;
    text-align: center;
    margin-bottom: 10px;
    color: var(--text-secondary);
}

.progress-bar {
    height: 8px;
    background-color: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background-color: var(--accent);
    transition: width 0.3s;
}

.quiz-question {
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 12px;
    margin-bottom: 20px;
    font-size: 1.1rem;
    line-height: 1.7;
    border: 1px solid var(--border);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.quiz-option {
    padding: 16px 20px;
    background-color: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
}

.quiz-option:hover:not(.disabled) {
    border-color: var(--accent);
    background-color: var(--accent-light);
}

.quiz-option.correct {
    border-color: var(--success);
    background-color: rgba(16, 185, 129, 0.1);
}

.quiz-option.wrong {
    border-color: var(--error);
    background-color: rgba(239, 68, 68, 0.1);
}

.quiz-option.disabled {
    cursor: default;
}

.quiz-feedback {
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
}

.quiz-feedback.hidden {
    display: none;
}

.quiz-feedback.correct {
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--success);
    color: var(--success);
}

.quiz-feedback.wrong {
    background-color: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error);
    color: var(--error);
}

#nextQuizBtn {
    margin-top: 20px;
    width: 100%;
}

#nextQuizBtn.hidden {
    display: none;
}

.quiz-result {
    text-align: center;
    padding: 40px;
}

.quiz-score {
    font-size: 3rem;
    font-weight: bold;
    color: var(--accent);
    margin: 20px 0;
}

/* 시뮬레이션 */
.sim-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.sim-tab {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid var(--border);
}

.sim-tab:hover,
.sim-tab.active {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
}

.sim-content {
    display: none;
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid var(--border);
}

.sim-content.active {
    display: block;
}

.sim-controls {
    margin: 20px 0;
    padding: 20px;
    background-color: var(--bg-tertiary);
    border-radius: 10px;
}

.sim-controls label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.sim-controls input[type="range"] {
    width: 100%;
    margin-bottom: 16px;
    accent-color: var(--accent);
}

.sim-controls.two-groups {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.group-control h4 {
    color: var(--accent);
    margin-bottom: 15px;
}

.chart-container {
    position: relative;
    height: 400px;
    margin: 20px 0;
}

.sim-explanation,
.sim-result {
    padding: 20px;
    background-color: var(--bg-tertiary);
    border-radius: 10px;
    margin-top: 20px;
}

.sim-explanation h4 {
    color: var(--accent);
    margin-bottom: 10px;
}

.sim-explanation ul {
    margin-left: 20px;
    color: var(--text-secondary);
}

.sim-result p {
    margin-bottom: 8px;
    color: var(--text-secondary);
}

/* 학습 현황 */
.progress-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.progress-card {
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border);
}

.progress-card h3 {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 15px;
}

.big-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--accent);
}

.progress-card p {
    color: var(--text-muted);
    margin-top: 5px;
}

.progress-detail {
    background-color: var(--bg-secondary);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid var(--border);
    margin-bottom: 20px;
}

.category-progress {
    margin-top: 20px;
}

.category-progress-item {
    margin-bottom: 20px;
}

.category-progress-item label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.category-progress-item .progress-bar {
    height: 12px;
}

/* 반응형 */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -260px;
        z-index: 1000;
        transition: left 0.3s;
    }

    .sidebar.open {
        left: 0;
    }

    .main-content {
        margin-left: 0;
        padding: 20px;
    }

    .sim-controls.two-groups {
        grid-template-columns: 1fr;
    }

    .roadmap-branches {
        flex-direction: column;
        align-items: center;
    }
}

/* 유틸리티 */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

/* t-검정 시뮬레이션 개선 스타일 */
.stats-comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 15px;
}

.stats-group {
    padding: 15px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.stats-group h5 {
    color: var(--accent);
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.stats-group p {
    margin-bottom: 6px;
    font-size: 0.95rem;
}

.ttest-results {
    margin-top: 15px;
    padding: 15px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

.ttest-results p {
    margin-bottom: 8px;
}

.data-details {
    margin-top: 20px;
    background-color: var(--bg-tertiary);
    border-radius: 10px;
    overflow: hidden;
}

.data-details summary {
    padding: 15px 20px;
    cursor: pointer;
    font-weight: 600;
    color: var(--accent);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
}

.data-details summary:hover {
    background-color: var(--accent-light);
}

.data-details[open] summary {
    border-radius: 10px 10px 0 0;
}

.data-tables {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    padding: 20px;
}

.data-table-container h5 {
    color: var(--accent);
    margin-bottom: 10px;
}

.data-table {
    max-height: 300px;
    overflow-y: auto;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    padding: 10px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
}

.data-table .data-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 8px;
    border-bottom: 1px solid var(--border);
}

.data-table .data-row:nth-child(even) {
    background-color: var(--bg-tertiary);
}

.data-table .data-row .index {
    color: var(--text-muted);
    width: 30px;
}

.data-table .data-row .value {
    color: var(--text-primary);
    font-weight: 500;
}

.sim-result h4 {
    color: var(--accent);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent-light);
}

@media (max-width: 768px) {
    .stats-comparison,
    .data-tables {
        grid-template-columns: 1fr;
    }
}

/* ADSP 시험 정보 스타일 */
.exam-info {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 25px;
    border: 1px solid var(--border);
    margin-bottom: 30px;
}

.exam-info h2 {
    margin-top: 0;
    margin-bottom: 20px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
}

.info-item {
    background-color: var(--bg-tertiary);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.info-item strong {
    display: block;
    color: var(--accent);
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.info-item span {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
}