/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --text-color: #333;
    --text-light: #666;
    --text-lighter: #999;
    --bg-color: #fff;
    --bg-light: #f8f9fa;
    --border-color: #e1e8ed;
    --shadow-light: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-medium: 0 4px 20px rgba(0,0,0,0.15);
    --shadow-heavy: 0 8px 30px rgba(0,0,0,0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --border-radius: 8px;
    --border-radius-large: 12px;
    --max-width: 1200px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    font-size: 16px;
    overflow-x: hidden;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-logo i {
    margin-right: 10px;
    font-size: 1.8rem;
    color: var(--secondary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-menu a:hover {
    color: var(--secondary-color);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary-color);
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    margin: 3px 0;
    transition: var(--transition);
}

/* 英雄区域 */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="25" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="25" cy="75" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-content {
    animation: slideInLeft 1s ease-out;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #fff, #e3f2fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    display: block;
    font-size: 1.5rem;
    font-weight: 400;
    margin-top: 0.5rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.25rem;
    line-height: 1.6;
    margin-bottom: 2rem;
    opacity: 0.9;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

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

.btn-primary:hover {
    background: #c0392b;
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: slideInRight 1s ease-out;
}

.cube-demo {
    perspective: 1000px;
    animation: float 3s ease-in-out infinite;
}

.cube-3d {
    width: 150px;
    height: 150px;
    position: relative;
    transform-style: preserve-3d;
    transform: rotateX(-20deg) rotateY(30deg);
    animation: rotate3d 4s linear infinite;
}

.face {
    position: absolute;
    width: 150px;
    height: 150px;
    border: 3px solid #333;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.2rem;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.3);
}

.front { 
    background: #ffffff; 
    transform: translateZ(75px); 
}
.back { 
    background: #f1c40f; 
    transform: rotateY(180deg) translateZ(75px); 
}
.right { 
    background: #e74c3c; 
    transform: rotateY(90deg) translateZ(75px); 
}
.left { 
    background: #e67e22; 
    transform: rotateY(-90deg) translateZ(75px); 
}
.top { 
    background: #3498db; 
    transform: rotateX(90deg) translateZ(75px); 
}
.bottom { 
    background: #27ae60; 
    transform: rotateX(-90deg) translateZ(75px); 
}

/* 模拟器部分 */
.simulator-section {
    padding: 80px 0;
    background: var(--bg-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.section-title i {
    color: var(--secondary-color);
    margin-right: 10px;
}

.section-description {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.simulator-container {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.cube-container {
    display: flex;
    justify-content: center;
    align-items: center;
    background: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    perspective: 1000px;
}

.rubiks-cube {
    width: 300px;
    height: 300px;
    position: relative;
    transform-style: preserve-3d;
    transform: rotateX(-20deg) rotateY(30deg);
    cursor: grab;
    user-select: none;
    touch-action: none;
}

.cube-face {
    position: absolute;
    top: 0;
    left: 0;
    width: 300px;
    height: 300px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    border: 2px solid #333;
    border-radius: var(--border-radius);
    overflow: hidden;
    backface-visibility: hidden;
}

.face-front { 
    transform: translateZ(150px);
    background: #ffffff;
}
.face-back { 
    transform: rotateY(180deg) translateZ(150px);
    background: #f1c40f;
}
.face-right { 
    transform: rotateY(90deg) translateZ(150px);
    background: #e74c3c;
}
.face-left { 
    transform: rotateY(-90deg) translateZ(150px);
    background: #e67e22;
}
.face-top { 
    transform: rotateX(90deg) translateZ(150px);
    background: #3498db;
}
.face-bottom { 
    transform: rotateX(-90deg) translateZ(150px);
    background: #27ae60;
}

.cube-piece {
    border: 1px solid #333;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 0.8rem;
    cursor: inherit;
    transition: var(--transition);
}

.cube-piece:hover {
    transform: scale(1.05);
    box-shadow: 0 0 10px rgba(0,0,0,0.3);
}

.color-white { background: #ffffff; color: #333; }
.color-yellow { background: #f1c40f; color: #333; }
.color-red { background: #e74c3c; color: white; }
.color-orange { background: #e67e22; color: white; }
.color-blue { background: #3498db; color: white; }
.color-green { background: #27ae60; color: white; }

.controls-panel {
    background: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    height: fit-content;
}

.control-group {
    margin-bottom: 2rem;
}

.control-group:last-child {
    margin-bottom: 0;
}

.control-group h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--primary-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.button-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
}

.control-btn {
    padding: 12px 8px;
    border: 2px solid var(--border-color);
    background: white;
    color: var(--text-color);
    font-weight: 600;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
}

.control-btn:hover {
    background: var(--secondary-color);
    color: white;
    border-color: var(--secondary-color);
    transform: translateY(-2px);
}

.control-btn:active {
    transform: translateY(0);
}

.status-info {
    margin-bottom: 1rem;
}

.status-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    background: var(--bg-light);
    border-radius: var(--border-radius);
}

.status-label {
    font-weight: 600;
    color: var(--text-light);
}

.status-value {
    font-weight: 700;
    color: var(--primary-color);
}

.status-buttons {
    display: flex;
    gap: 0.5rem;
}

.btn-warning {
    background: var(--warning-color);
    color: white;
    border: none;
}

.btn-warning:hover {
    background: #e67e22;
}

.btn-danger {
    background: var(--accent-color);
    color: white;
    border: none;
}

.btn-danger:hover {
    background: #c0392b;
}

.move-history {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 1rem;
    max-height: 150px;
    overflow-y: auto;
}

.move-list {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.4;
}

.move-item {
    display: inline-block;
    margin: 2px;
    padding: 2px 6px;
    background: var(--secondary-color);
    color: white;
    border-radius: 4px;
}

/* 教程部分 */
.tutorial-section {
    padding: 80px 0;
}

.tutorial-nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}

.tutorial-tab {
    padding: 12px 20px;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    color: var(--text-light);
}

.tutorial-tab:hover {
    border-color: var(--secondary-color);
    color: var(--secondary-color);
}

.tutorial-tab.active {
    background: var(--secondary-color);
    border-color: var(--secondary-color);
    color: white;
}

.tutorial-content {
    max-width: 900px;
    margin: 0 auto;
}

.tutorial-step {
    display: none;
    background: white;
    border-radius: var(--border-radius-large);
    padding: 3rem;
    box-shadow: var(--shadow-medium);
    animation: fadeIn 0.5s ease-in;
}

.tutorial-step.active {
    display: block;
}

.tutorial-step h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    border-bottom: 3px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.step-content h4 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 2rem 0 1rem;
}

.step-content h5 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin: 1.5rem 0 0.5rem;
}

.step-content p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: var(--text-light);
}

.step-content ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.step-content li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
    color: var(--text-light);
}

.concept-explanation,
.notation-explanation {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin: 2rem 0;
}

.color-guide {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.color-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.color-box {
    width: 20px;
    height: 20px;
    border-radius: 4px;
    border: 1px solid #333;
}

.color-box.white { background: #ffffff; }
.color-box.yellow { background: #f1c40f; }
.color-box.red { background: #e74c3c; }
.color-box.orange { background: #e67e22; }
.color-box.blue { background: #3498db; }
.color-box.green { background: #27ae60; }

.notation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.notation-item {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--secondary-color);
}

.algorithm-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    margin: 2rem 0;
}

.algorithm-card {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 1rem 0;
    backdrop-filter: blur(10px);
}

.algorithm-card h5 {
    color: #fff;
    margin: 0 0 0.5rem 0;
    font-size: 1.1rem;
}

.algorithm-card p {
    margin: 0.5rem 0;
    color: rgba(255, 255, 255, 0.9);
}

.algorithm-card code {
    background: rgba(0, 0, 0, 0.3);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: #fff;
}

.algorithm-pair {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.algorithm-demo {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin: 1rem 0;
}

.step-demo {
    margin: 1rem 0;
    padding: 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
}

.step-demo strong {
    color: #fff;
    font-size: 1.1rem;
}

.tips-section {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin: 2rem 0;
}

.tip-card {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
}

.tip-card i {
    color: var(--warning-color);
    font-size: 1.5rem;
    margin-top: 0.25rem;
}

.tip-card strong {
    color: var(--primary-color);
    display: block;
    margin-bottom: 0.5rem;
}

.technique-analysis,
.pattern-recognition,
.logic-explanation,
.positioning-logic {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin: 2rem 0;
}

.technique-item,
.pattern-item,
.logic-item,
.positioning-item {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    margin: 1rem 0;
    border-left: 4px solid var(--success-color);
}

.situation-analysis {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1rem 0;
}

.situation-card {
    background: rgba(255, 255, 255, 0.1);
    padding: 1rem;
    border-radius: var(--border-radius);
    text-align: center;
}

.formula-breakdown {
    margin: 1rem 0;
}

.formula-step {
    margin: 0.5rem 0;
    padding: 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
}

.final-analysis {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin: 1rem 0;
}

.case-card {
    background: rgba(255, 255, 255, 0.1);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    text-align: center;
}

.completion-celebration {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    color: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    text-align: center;
    margin: 2rem 0;
}

.achievement-badges {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
}

.badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    backdrop-filter: blur(10px);
}

.badge i {
    font-size: 2rem;
    color: #ffd700;
}

/* 高级技巧部分 */
.advanced-section {
    padding: 80px 0;
    background: var(--bg-light);
}

.advanced-content {
    margin-top: 3rem;
}

.advanced-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.advanced-card {
    background: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border-top: 4px solid var(--secondary-color);
}

.advanced-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.advanced-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.technique-preview h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin: 1.5rem 0 0.5rem;
}

.technique-preview ul {
    padding-left: 1.5rem;
}

.technique-preview li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

/* 原理解析部分 */
.theory-section {
    padding: 80px 0;
}

.theory-content {
    margin-top: 3rem;
}

.theory-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.theory-card {
    background: white;
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-light);
    text-align: center;
    transition: var(--transition);
    border-top: 4px solid var(--accent-color);
}

.theory-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.theory-icon {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.theory-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.theory-text {
    text-align: left;
}

.theory-text p {
    margin-bottom: 1rem;
    line-height: 1.6;
    color: var(--text-light);
}

.math-formula {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
}

.physics-section {
    background: white;
    border-radius: var(--border-radius-large);
    padding: 3rem;
    box-shadow: var(--shadow-light);
}

.physics-section h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.physics-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.physics-item {
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: var(--border-radius);
}

.physics-item h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.physics-item p {
    color: var(--text-light);
    line-height: 1.6;
}

/* 页脚 */
.footer {
    background: var(--primary-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--secondary-color);
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    color: rgba(255, 255, 255, 0.7);
}

/* 动画 */
@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes rotate3d {
    from {
        transform: rotateX(-20deg) rotateY(30deg);
    }
    to {
        transform: rotateX(-20deg) rotateY(390deg);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .simulator-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .tutorial-nav {
        flex-direction: column;
        align-items: center;
    }
    
    .algorithm-pair {
        grid-template-columns: 1fr;
    }
    
    .final-analysis {
        grid-template-columns: 1fr;
    }
    
    .achievement-badges {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 200px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .cube-3d {
        width: 120px;
        height: 120px;
    }
    
    .face {
        width: 120px;
        height: 120px;
        font-size: 1rem;
    }
    
    .rubiks-cube {
        width: 250px;
        height: 250px;
    }
    
    .cube-face {
        width: 250px;
        height: 250px;
    }
    
    .tutorial-step {
        padding: 2rem;
    }
    
    .tutorial-step h3 {
        font-size: 1.5rem;
    }
}