@media (max-width: 600px) {
    .problem-title-group {
        gap: 0.5rem;
    }
    
    .leetcode-link span {
        display: none;
    }
    
    .timer-container {
        margin-left: 0.5rem;
    }
}

@media (max-width: 480px) {
    .leetcode-link {
        padding: 0.25rem 0.5rem;
    }
    
    .leetcode-link svg {
        width: 20px;
        height: 20px;
    }
    
    .problem-title-group {
        gap: 0.4rem;
    }
    
    .timer-container {
        gap: 0.25rem;
    }
    
    .problem-title {
        font-size: 1rem;
    }
    
    .timer-label {
        display: none;
    }
}:root {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-surface: #f1f3f5;
    --border-primary: #3350b4;
    --border-secondary: #5c7cfa;
    --text-primary: #212529;
    --text-secondary: #495057;
    --accent-primary: #3350b4;
    --accent-secondary: #4c6ef5;
    --accent-warning: #f59f00;
    --accent-danger: #f03e3e;
    --accent-success: #51cf66;
    --accent-info: #339af0;
    --shadow-primary: rgba(51, 80, 180, 0.1);
    --shadow-secondary: rgba(51, 80, 180, 0.05);
    --gradient-primary: linear-gradient(135deg, #3350b4 0%, #5c7cfa 100%);
    --gradient-secondary: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    --gradient-solution: linear-gradient(135deg, rgba(51, 80, 180, 0.05) 0%, rgba(92, 124, 250, 0.02) 100%);
    
    /* Code editor colors */
    --editor-bg: #1e1e1e;
    --editor-text: #d4d4d4;
    --editor-keyword: #569cd6;
    --editor-string: #ce9178;
    --editor-function: #dcdcaa;
    --editor-comment: #6a9955;
    --editor-number: #b5cea8;
    --editor-class: #4ec9b0;
    
    /* Test output colors - New design system */
    --test-bg: #1a1a1a;
    --test-surface: #252526;
    --test-border: #3e3e42;
    --test-text: #cccccc;
    --test-text-dim: #858585;
    --test-success: #4ec9b0;
    --test-success-bg: rgba(78, 201, 176, 0.1);
    --test-failure: #f48771;
    --test-failure-bg: rgba(244, 135, 113, 0.1);
    --test-warning: #dcdcaa;
    --test-warning-bg: rgba(220, 220, 170, 0.1);
}

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

body {
    font-family: 'Inter', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* New Test Results Design System */
.test-results-container {
    background: var(--test-bg);
    border-top: 1px solid var(--test-border);
    min-height: 200px;
    max-height: 400px;
    display: flex;
    flex-direction: column;
    transition: all 0.3s ease;
    position: relative;
}

.test-results-container.hidden {
    display: none !important;
}

/* Utility class for hiding elements */
.hidden {
    display: none !important;
}

.test-results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--test-surface);
    border-bottom: 1px solid var(--test-border);
}

.test-results-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--test-text);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.test-results-title svg {
    width: 16px;
    height: 16px;
    opacity: 0.8;
}

.test-results-close {
    background: transparent;
    border: none;
    color: var(--test-text-dim);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: 4px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.test-results-close:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--test-text);
}

.test-results-close svg {
    width: 16px;
    height: 16px;
}

.test-results-body {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    background: var(--test-bg);
}

/* Test Status Banners */
.test-status-banner {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.test-status-banner svg {
    width: 18px;
    height: 18px;
}

.test-status-success {
    background: var(--test-success-bg);
    color: var(--test-success);
    border: 1px solid rgba(78, 201, 176, 0.3);
}

.test-status-partial {
    background: var(--test-warning-bg);
    color: var(--test-warning);
    border: 1px solid rgba(220, 220, 170, 0.3);
}

/* Test Cases Grid */
.test-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 0.75rem;
    margin-bottom: 1rem;
}

/* Individual Test Case */
.test-case-card {
    background: var(--test-surface);
    border: 1px solid var(--test-border);
    border-radius: 6px;
    padding: 0.75rem;
    transition: all 0.2s ease;
}

.test-case-card:hover {
    background: rgba(255, 255, 255, 0.03);
    border-color: rgba(255, 255, 255, 0.1);
}

.test-case-card.passed {
    border-left: 3px solid var(--test-success);
}

.test-case-card.failed {
    border-left: 3px solid var(--test-failure);
}

.test-case-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.test-case-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.test-case-icon svg {
    width: 18px;
    height: 18px;
}

.test-case-icon.success svg {
    color: var(--test-success);
}

.test-case-icon.failure svg {
    color: var(--test-failure);
}

.test-case-name {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--test-text);
}

.test-case-status {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.125rem 0.5rem;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.test-case-status.pass {
    background: var(--test-success-bg);
    color: var(--test-success);
}

.test-case-status.fail {
    background: var(--test-failure-bg);
    color: var(--test-failure);
}

/* Test Case Details */
.test-case-details {
    font-size: 0.8125rem;
    line-height: 1.5;
}

.test-io-row {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    margin-bottom: 0.375rem;
    color: var(--test-text-dim);
}

.test-io-row:last-child {
    margin-bottom: 0;
}

.test-io-label {
    font-size: 0.75rem;
    color: var(--test-text-dim);
    min-width: 60px;
}

.test-io-value {
    font-family: 'JetBrains Mono', monospace;
    background: rgba(255, 255, 255, 0.05);
    padding: 0.125rem 0.5rem;
    border-radius: 4px;
    color: var(--test-text);
}

.test-io-value.error {
    color: var(--test-failure);
    background: var(--test-failure-bg);
}

/* Test Error Display */
.test-error-message {
    margin-top: 0.5rem;
    padding: 0.5rem;
    background: var(--test-failure-bg);
    border: 1px solid rgba(244, 135, 113, 0.3);
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--test-failure);
    line-height: 1.4;
}

/* Hidden Tests Notice */
.hidden-tests-notice {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    background: var(--test-surface);
    border: 1px solid var(--test-border);
    border-radius: 6px;
    padding: 0.75rem 1rem;
    font-size: 0.8125rem;
    color: var(--test-text-dim);
    line-height: 1.5;
}

.hidden-tests-notice svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
    margin-top: 2px;
    color: var(--test-warning);
}

.hidden-tests-notice strong {
    color: var(--test-text);
    font-weight: 600;
}

/* Execution Error */
.execution-error {
    background: var(--test-failure-bg);
    border: 1px solid rgba(244, 135, 113, 0.3);
    border-radius: 6px;
    padding: 1rem;
    margin: 0.5rem 0;
}

.execution-error-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--test-failure);
    font-weight: 600;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
}

.execution-error-header svg {
    width: 18px;
    height: 18px;
}

.execution-error-details {
    font-family: 'JetBrains Mono', monospace;
    color: var(--test-text);
    font-size: 0.8125rem;
    line-height: 1.5;
    white-space: pre-wrap;
}

/* Loading State */
.test-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem;
    color: var(--test-text-dim);
}

.test-loading-spinner {
    width: 32px;
    height: 32px;
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 0.8s linear infinite;
    margin-bottom: 1rem;
}

.test-loading-text {
    font-size: 0.875rem;
}

/* Scrollbar Styling */
.test-results-body::-webkit-scrollbar {
    width: 8px;
}

.test-results-body::-webkit-scrollbar-track {
    background: var(--test-bg);
}

.test-results-body::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

.test-results-body::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* Pyodide Status - Loading Indicator */
.pyodide-status {
    position: absolute;
    bottom: 0.5rem;
    right: 0.5rem;
    background: rgba(30, 30, 30, 0.9);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.8125rem;
    font-family: 'Inter', sans-serif;
    color: rgba(255, 255, 255, 0.7);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    z-index: 100;
    transition: opacity 0.3s ease;
}

/* Acceptance Rate Badge */
.acceptance-rate {
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    background: rgba(51, 154, 240, 0.1);
    color: var(--accent-info);
    border: 1px solid var(--accent-info);
}

/* Floating Navigation */
.floating-nav {
    position: fixed;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.floating-nav.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.floating-nav.visible {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.nav-item {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 2px solid var(--border-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.nav-item:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: scale(1.1);
}

.nav-item svg {
    width: 20px;
    height: 20px;
    color: var(--accent-primary);
}

.nav-item:hover svg {
    color: white;
}

.nav-item::before {
    content: attr(title);
    position: absolute;
    right: 60px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--text-primary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    font-size: 0.8rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.nav-item:hover::before {
    opacity: 1;
}

/* Hide floating nav on small screens */
@media (max-width: 1200px) {
    .floating-nav {
        display: none;
    }
}

/* Button Icons */
.btn-icon {
    width: 16px;
    height: 16px;
    display: inline-block;
    vertical-align: middle;
}

.editor-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.editor-btn.run {
    background: var(--accent-success);
}

.editor-btn.run:hover {
    background: #40c057;
}

/* Animation */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* SVG Icons */
.icon {
    display: inline-flex;
    width: 24px;
    height: 24px;
    align-items: center;
    justify-content: center;
}

.icon-large {
    width: 40px;
    height: 40px;
}

/* Problem Section Styles */
.problem-section {
    background: var(--bg-secondary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.problem-header {
    background: var(--bg-secondary);
    border-bottom: 1px solid #e9ecef;
    padding: 1.5rem 2rem;
    box-shadow: 0 2px 10px var(--shadow-secondary);
}

@media (max-width: 768px) {
    .problem-header {
        padding: 1rem;
    }
}

.header-content {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: nowrap;
}

.problem-title-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: nowrap;
}

.problem-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.home-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    background: var(--bg-secondary);
    border: 2px solid var(--accent-primary);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
    position: absolute;
    left: 2rem;
    top: 50%;
    transform: translateY(-50%);
    overflow: hidden;
    z-index: 10;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.home-button:hover {
    background: var(--accent-primary);
    transform: translateY(-50%) scale(1.05);
    box-shadow: 0 4px 16px rgba(51, 80, 180, 0.4);
}

.home-button svg {
    width: 22px;
    height: 22px;
    color: var(--accent-primary);
    transition: all 0.3s ease;
}

.home-button:hover svg {
    color: white;
    transform: scale(1.1);
}

.home-button::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.home-button:hover::before {
    width: 120px;
    height: 120px;
}

/* Adjust header content padding to make room for home button */
.header-content {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: nowrap;
    position: relative;
    padding-left: 5rem;
}

.problem-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

.leetcode-link {
    display: inline-flex;
    align-items: center;
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.3rem 0.8rem;
    border: 1px solid var(--accent-primary);
    border-radius: 4px;
    transition: all 0.2s ease;
}

.leetcode-link:hover {
    background: var(--accent-primary);
    color: white;
}

.difficulty-badge {
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
}

.difficulty-easy {
    background: rgba(81, 207, 102, 0.1);
    color: var(--accent-success);
    border: 1px solid var(--accent-success);
}
.difficulty-medium {
    background: rgba(245, 159, 0, 0.1);
    color: var(--accent-warning);
    border: 1px solid var(--accent-warning);
}

.difficulty-hard {
    background: rgba(240, 62, 62, 0.1);
    color: var(--accent-danger);
    border: 1px solid var(--accent-danger);
}

/* Timer */
.timer-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.timer-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.timer {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    background: var(--bg-surface);
    border-radius: 8px;
    min-width: 80px;
    text-align: center;
    display: inline-block;
}

.timer.active {
    color: var(--accent-primary);
    background: rgba(51, 80, 180, 0.1);
    animation: pulse 2s infinite;
}

.timer.warning {
    color: var(--accent-warning);
    background: rgba(245, 159, 0, 0.1);
}

.timer.danger {
    color: var(--accent-danger);
    background: rgba(240, 62, 62, 0.1);
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.7; }
    100% { opacity: 1; }
}

/* Problem Content */
.problem-content {
    flex: 1;
    max-width: 1600px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    gap: 0;
    height: calc(100vh - 80px);
}

.problem-statement {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
    background: var(--bg-secondary);
    border-right: 1px solid #e9ecef;
}

.problem-statement h2 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.problem-statement p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
}

.problem-statement pre {
    background: #f6f8fa;
    border: 1px solid #e1e4e8;
    border-radius: 6px;
    padding: 1rem;
    margin: 1rem 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    overflow-x: auto;
}

.problem-statement code {
    background: #f6f8fa;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
}

/* Problem statement 내의 리스트 들여쓰기 조정 */
.problem-statement ol,
.problem-statement ul {
    padding-left: 2.5rem;
    margin: 1rem 0;
}

.problem-statement ol li,
.problem-statement ul li {
    margin-bottom: 0.5rem;
    line-height: 1.8;
}

/* Constraints 등 h2 다음의 리스트는 상단 여백 줄이기 */
.problem-statement h2 + ul,
.problem-statement h2 + ol {
    margin-top: 0.5rem;
}

/* Code Editor */
.code-editor-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--editor-bg);
}

.editor-header {
    background: #2d2d30;
    padding: 0.8rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #3e3e42;
}

.editor-tabs {
    display: flex;
    gap: 0;
}

.editor-tab {
    padding: 0.5rem 1rem;
    background: #1e1e1e;
    color: #cccccc;
    border: none;
    cursor: pointer;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    border-top-left-radius: 4px;
    border-top-right-radius: 4px;
    transition: all 0.2s ease;
}

.editor-tab.active {
    background: #1e1e1e;
    color: white;
}

.editor-actions {
    display: flex;
    gap: 0.7rem;
}

.editor-btn {
    padding: 0.4rem 1rem;
    background: var(--accent-success);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.editor-btn:hover {
    background: #40c057;
    transform: translateY(-1px);
}

.editor-btn.reset {
    background: var(--text-secondary);
}

.editor-btn.reset:hover {
    background: #343a40;
}

.editor-btn.run {
    background: var(--accent-success);
}

.editor-btn.run:hover {
    background: #40c057;
}

.code-editor {
    flex: 1;
    padding: 1rem;
    background: var(--editor-bg);
    color: var(--editor-text);
    font-family: 'JetBrains Mono', monospace;
    font-variant-ligatures: none;
    font-size: 0.95rem;
    line-height: 1.6;
    overflow-y: auto;
    position: relative;
}

#codeDisplay {
    white-space: pre-wrap;
    word-wrap: break-word;
}

#codeInput {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 1rem;
    background: transparent;
    border: none;
    color: transparent;
    caret-color: white;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: none;
    outline: none;
    tab-size: 4;
    z-index: 2;
}

/* Syntax highlighting classes */
.keyword { color: var(--editor-keyword); }
.string { color: var(--editor-string); }
.function { color: var(--editor-function); }
.comment { color: var(--editor-comment); }
.number { color: var(--editor-number); }
.class-name { color: var(--editor-class); }

/* Divider */
.section-divider {
    height: 100px;
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.section-divider::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 200%;
    height: 2px;
    background: var(--gradient-primary);
    animation: dividerSlide 3s infinite;
}

@keyframes dividerSlide {
    0% { left: -100%; }
    100% { left: 100%; }
}

.divider-text {
    background: var(--bg-secondary);
    padding: 0.8rem 2rem;
    border-radius: 30px;
    font-weight: 600;
    color: var(--accent-primary);
    box-shadow: 0 4px 20px var(--shadow-primary);
    z-index: 1;
}

/* Solution Section */
.solution-section {
    background: var(--gradient-solution);
    padding: 4rem 0 3rem 0;
    min-height: 100vh;
}

.solution-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.solution-header {
    text-align: center;
    margin-bottom: 3rem;
}

.solution-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.solution-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: 20px;
    font-size: 0.9rem;
    box-shadow: 0 2px 10px var(--shadow-secondary);
}

.meta-label {
    color: var(--text-secondary);
}

.meta-value {
    font-weight: 600;
    color: var(--accent-primary);
}

/* Concept boxes with gradient */
.concept-card {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 4px 20px var(--shadow-secondary);
    border: 1px solid transparent;
    background-clip: padding-box;
    position: relative;
}

.concept-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: 16px;
    padding: 1px;
    background: var(--gradient-primary);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    -webkit-mask-composite: xor;
    z-index: -1;
}

.concept-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.concept-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1.2rem;
}

.concept-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--accent-primary);
}

/* Approach cards */
.approach-card {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-left: 4px solid var(--accent-primary);
    box-shadow: 0 2px 10px var(--shadow-secondary);
    transition: all 0.3s ease;
}

.approach-card:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 20px var(--shadow-primary);
}

.approach-card.optimal {
    border-left-color: var(--accent-success);
    border-width: 6px;
    background: linear-gradient(to right, rgba(81, 207, 102, 0.05), var(--bg-secondary));
}

/* Key insights */
.insight-box {
    background: linear-gradient(135deg, rgba(51, 154, 240, 0.1) 0%, rgba(51, 154, 240, 0.05) 100%);
    border-left: 4px solid var(--accent-info);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.insight-title {
    color: var(--accent-info);
    font-weight: 600;
    margin-bottom: 0.8rem;
    font-size: 1.05rem;
}

/* Think Aloud Box */
.think-aloud-box {
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.05) 0%, rgba(255, 107, 107, 0.02) 100%);
    border: 2px solid rgba(255, 107, 107, 0.3);
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.think-aloud-title {
    color: var(--accent-danger);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.think-aloud-content {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    line-height: 2;
    color: var(--text-primary);
}

.think-aloud-step {
    margin-bottom: 0.8rem;
    padding-left: 1rem;
}

.think-aloud-step strong {
    color: var(--accent-primary);
    font-weight: 600;
}

/* Code blocks in solution */
.solution-code {
    background: #f6f8fa;
    border: 1px solid #e1e4e8;
    border-radius: 8px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.solution-code-header {
    background: #f1f3f5;
    padding: 0.8rem 1rem;
    border-bottom: 1px solid #e1e4e8;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.solution-code-title {
    font-weight: 600;
    color: var(--text-primary);
}

.complexity-tags {
    display: flex;
    gap: 0.5rem;
}

.complexity-tag {
    padding: 0.2rem 0.6rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
}

/* Comparison table */
.comparison-table {
    overflow-x: auto;
    margin: 2rem 0;
}

.comparison-table table {
    width: 100%;
    background: var(--bg-secondary);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 10px var(--shadow-secondary);
}

.comparison-table th {
    background: var(--gradient-primary);
    color: white;
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

.comparison-table td {
    padding: 1rem;
    border-bottom: 1px solid #e9ecef;
}

.comparison-table tr:hover {
    background: var(--bg-surface);
}

/* Important text emphasis */
.important {
    color: var(--accent-danger);
    font-weight: 700;
}

.highlight-blue {
    color: var(--accent-primary);
    font-weight: 700;
}

.highlight-green {
    color: var(--accent-success);
    font-weight: 700;
}

/* Interview tips list */
.interview-steps {
    counter-reset: step-counter;
    list-style: none;
    padding: 0;
}

.interview-steps li {
    counter-increment: step-counter;
    position: relative;
    padding-left: 3rem;
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.interview-steps li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 2rem;
    height: 2rem;
    background: var(--gradient-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

/* Hash collision warning */
.collision-warning {
    background: rgba(245, 159, 0, 0.1);
    border: 1px solid var(--accent-warning);
    border-radius: 8px;
    padding: 1rem;
    margin: 1rem 0;
}

.collision-warning-title {
    color: var(--accent-warning);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

/* Table SVG icons */
.comparison-table svg {
    vertical-align: middle;
    display: inline-block;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .problem-content {
        flex-direction: column;
        height: auto;
    }
    
    .problem-statement {
        border-right: none;
        border-bottom: 1px solid #e9ecef;
        height: 400px;
    }
    
    .code-editor-container {
        height: 400px;
    }
}

@media (max-width: 768px) {
    .problem-title-group {
        gap: 0.75rem;
    }
    
    .problem-title {
        font-size: 1.1rem;
    }
    
    .problem-number {
        font-size: 1rem;
    }
    
    .difficulty-badge {
        font-size: 0.75rem;
        padding: 0.25rem 0.6rem;
    }
    
    .timer {
        font-size: 1rem;
        padding: 0.4rem 0.8rem;
        min-width: 70px;
    }
    
    .timer-label {
        font-size: 0.8rem;
    }
    
    .solution-container {
        padding: 0 1rem;
    }
    
    .test-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .test-results-container {
        max-height: 350px;
    }
}

/* Additional styles for better integration */
.hint-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.hint-item {
    position: relative;
    padding-left: 0;
}

.hint-number {
    color: var(--accent-primary);
    font-weight: 600;
    display: inline-block;
    margin-bottom: 0.3rem;
}

.hint-item p {
    margin: 0;
    line-height: 1.7;
    color: var(--text-primary);
}

/* Mistake List Styling */
.mistake-list {
    line-height: 2;
    padding-left: 1.5rem;
}

.mistake-list li {
    margin-bottom: 0.8rem;
}

.mistake-list li:last-child {
    margin-bottom: 0;
}