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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    line-height: 1.6;
    color: #333;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: white;
    padding: 40px;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    text-align: center;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 10px;
    color: #667eea;
}

header p {
    font-size: 1.1rem;
    color: #666;
}

/* Navigation Tabs */
.nav-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    background: white;
    padding: 15px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.nav-btn {
    padding: 10px 16px;
    border: 2px solid #ddd;
    background: white;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    color: #666;
}

.nav-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.nav-btn.active {
    background: #667eea;
    border-color: #667eea;
    color: white;
}

/* Main Content */
main {
    background: white;
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.section {
    display: none;
    animation: fadeIn 0.4s ease;
}

.section.active {
    display: block;
}

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

h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: #667eea;
    border-bottom: 3px solid #667eea;
    padding-bottom: 10px;
}

h3 {
    font-size: 1.3rem;
    margin-top: 30px;
    margin-bottom: 15px;
    color: #333;
}

h4 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: #555;
}

p {
    margin-bottom: 15px;
    color: #666;
}

code {
    background: #f5f5f5;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    color: #d63384;
}

/* Summary Box */
.summary-box {
    background: linear-gradient(135deg, #667eea15 0%, #764ba215 100%);
    padding: 20px;
    border-left: 4px solid #667eea;
    border-radius: 8px;
    margin: 20px 0;
}

.summary-box p {
    margin-bottom: 10px;
}

/* Code Blocks */
.code-block {
    margin: 20px 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.code-block .label {
    background: #f5f5f5;
    padding: 10px 15px;
    font-weight: 600;
    border-bottom: 1px solid #ddd;
}

.code-block .label.good {
    background: #d4edda;
    color: #155724;
}

.code-block .label.bad {
    background: #f8d7da;
    color: #721c24;
}

.code-block pre {
    background: #2d2d2d;
    color: #f8f8f2;
    padding: 15px;
    overflow-x: auto;
    margin: 0;
}

.code-block code {
    background: none;
    color: inherit;
    padding: 0;
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Flow Diagram */
.flow-diagram {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 30px 0;
    flex-wrap: wrap;
    justify-content: center;
}

.step {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px;
    border-radius: 8px;
    min-width: 150px;
    text-align: center;
    flex: 1;
    min-height: 100px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.step-num {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 10px;
}

.arrow {
    font-size: 1.5rem;
    color: #667eea;
    font-weight: bold;
}

/* Issues Grid */
.issues-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.issue-card {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #ff6b6b;
}

.issue-card h4 {
    color: #ff6b6b;
    margin-bottom: 10px;
}

/* Batching Diagram */
.batching-diagram {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 20px 0;
}

.box {
    padding: 20px;
    border-radius: 8px;
    border: 2px solid #ddd;
}

.box.bad {
    border-color: #ff6b6b;
    background: #fff5f5;
}

.box.good {
    border-color: #51cf66;
    background: #f1fce4;
}

.box h4 {
    margin-bottom: 15px;
}

.batch-item {
    background: white;
    padding: 10px;
    margin: 8px 0;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

.result {
    margin-top: 15px;
    padding: 12px;
    border-radius: 4px;
    font-weight: 600;
    text-align: center;
}

.box.bad .result {
    background: #ffe0e0;
    color: #c92a2a;
}

.box.good .result {
    background: #d3f9d8;
    color: #2b8a3e;
}

/* Symptoms Grid */
.symptoms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.symptom {
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #999;
}

.symptom.critical {
    background: #fff5f5;
    border-left-color: #ff6b6b;
}

.symptom.high {
    background: #fff8e1;
    border-left-color: #ffa500;
}

.symptom h4 {
    margin-bottom: 10px;
}

.example {
    background: white;
    padding: 10px;
    border-radius: 4px;
    font-size: 0.9rem;
    margin-top: 10px;
    font-family: 'Courier New', monospace;
}

/* Scenario Box */
.scenario-box {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
}

.timeline {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.event {
    background: white;
    padding: 15px;
    border-radius: 6px;
    border-left: 3px solid #667eea;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
}

.result {
    background: linear-gradient(135deg, #fff5f5 0%, #ffe0e0 100%);
    padding: 15px;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    color: #c92a2a;
    border: 2px solid #ff6b6b;
}

/* Fix Cards */
.fix-card {
    margin: 20px 0;
    border-radius: 8px;
    overflow: hidden;
}

.before-after {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    margin-bottom: 15px;
}

.before {
    background: #fff5f5;
    padding: 20px;
    border-right: 1px solid #ff6b6b;
}

.after {
    background: #f1fce4;
    padding: 20px;
}

.before h4 {
    color: #ff6b6b;
}

.after h4 {
    color: #51cf66;
}

.explanation {
    background: linear-gradient(135deg, #667eea15 0%, #764ba215 100%);
    padding: 15px;
    border-radius: 6px;
    border-left: 4px solid #667eea;
}

/* Golden Rule */
.golden-rule {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    padding: 25px;
    border-radius: 8px;
    text-align: center;
    margin: 25px 0;
    box-shadow: 0 4px 12px rgba(255, 215, 0, 0.3);
}

.golden-rule h4 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: #333;
}

.golden-rule code {
    background: rgba(0, 0, 0, 0.1);
    padding: 8px 12px;
    font-size: 1.1rem;
    color: #333;
}

/* Checklist */
.checklist {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 12px;
    margin: 20px 0;
}

.check-item {
    padding: 12px 16px;
    border-radius: 6px;
    background: #f8f9fa;
    border-left: 4px solid #ddd;
}

.check-item.yes {
    background: #d4edda;
    border-left-color: #51cf66;
}

/* Comparison Grid */
.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 20px 0;
}

.pattern {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
}

.pattern:first-child {
    background: #fff5f5;
    border: 2px solid #ff6b6b;
}

.pattern:last-child {
    background: #f1fce4;
    border: 2px solid #51cf66;
}

.pattern h4 {
    margin-bottom: 15px;
}

.pattern pre {
    background: #2d2d2d;
    color: #f8f8f2;
    padding: 15px;
    border-radius: 6px;
    overflow-x: auto;
}

.pattern code {
    background: none;
    color: inherit;
    padding: 0;
}

/* FAQ */
.faq-item {
    background: #f8f9fa;
    padding: 20px;
    margin: 15px 0;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.faq-item h4 {
    color: #667eea;
    margin-bottom: 10px;
}

.faq-item p {
    margin: 0;
}

.yes {
    background: #d4edda;
    color: #155724;
    padding: 2px 6px;
    border-radius: 3px;
    font-weight: 600;
}

.no {
    background: #f8d7da;
    color: #721c24;
    padding: 2px 6px;
    border-radius: 3px;
    font-weight: 600;
}

.faq-item ol,
.faq-item ul {
    margin-left: 20px;
    margin-top: 10px;
}

.faq-item li {
    margin: 8px 0;
}

/* Footer */
footer {
    background: white;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

footer p {
    margin-bottom: 8px;
    color: #666;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 20px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    main {
        padding: 20px;
    }

    h2 {
        font-size: 1.5rem;
    }

    .nav-tabs {
        flex-direction: column;
    }

    .nav-btn {
        width: 100%;
    }

    .batching-diagram {
        grid-template-columns: 1fr;
    }

    .before-after {
        grid-template-columns: 1fr;
    }

    .before {
        border-right: none;
        border-bottom: 2px solid #ff6b6b;
        margin-bottom: 15px;
    }

    .comparison-grid {
        grid-template-columns: 1fr;
    }

    .flow-diagram {
        flex-direction: column;
    }

    .arrow {
        transform: rotate(90deg);
    }
}