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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a0033 50%, #000033 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    color: #ffffff;
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

/* Ensure all text elements can break properly */
h1, h2, h3, h4, h5, h6, p, li, span, div, a, label {
    word-wrap: break-word;
    overflow-wrap: break-word;
}

/* Prevent horizontal overflow */
pre, code, textarea {
    max-width: 100%;
    overflow-x: auto;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes neonPulse {
    0% {
        box-shadow: 0 0 20px rgba(0, 217, 255, 0.8), 
                    0 0 40px rgba(0, 217, 255, 0.6), 
                    0 0 60px rgba(0, 217, 255, 0.4);
    }
    50% {
        box-shadow: 0 0 30px rgba(0, 217, 255, 1), 
                    0 0 60px rgba(0, 217, 255, 0.8), 
                    0 0 90px rgba(0, 217, 255, 0.6);
    }
    100% {
        box-shadow: 0 0 20px rgba(0, 217, 255, 0.8), 
                    0 0 40px rgba(0, 217, 255, 0.6), 
                    0 0 60px rgba(0, 217, 255, 0.4);
    }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    overflow-x: hidden;
    width: 100%;
    box-sizing: border-box;
}

header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #ffffff 0%, #e0f2ff 100%);
    margin-bottom: 30px;
    box-shadow: 0 0 30px #00ffff, 0 0 60px #ff00ff, 0 4px 20px rgba(0, 0, 0, 0.3);
    border: 3px solid #000000;
    position: relative;
}

header::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #00ffff 0%, #ff00ff 50%, #00ffff 100%);
    background-size: 200% 100%;
    animation: lineSlide 3s linear infinite;
}

@keyframes lineSlide {
    0% { background-position: 0% 0%; }
    100% { background-position: 200% 0%; }
}

header h1 {
    font-size: 2.5em;
    color: #000000;
    font-weight: 900;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 3px;
    text-shadow: 2px 2px 0px #00ffff, -2px -2px 0px #ff00ff;
}

.subtitle {
    font-size: 1.2em;
    color: #666;
    font-weight: 400;
}

.progress-section {
    background: white;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.progress-section h2 {
    font-size: 1.5em;
    color: #1a1a1a;
    margin-bottom: 20px;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background: #e5e7eb;
    position: relative;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #00d9ff 0%, #00d9ff 100%);
    width: 0%;
    transition: width 0.5s ease;
}

.progress-text {
    text-align: center;
    margin-top: 10px;
    font-weight: 600;
    color: #00d9ff;
    font-size: 1.1em;
}

.lesson {
    background: white;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.lesson-header {
    background: #f9fafb;
    padding: 20px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    border-left: 4px solid #00d9ff;
}

.lesson-header:hover {
    background: #f3f4f6;
}

.lesson-header h2 {
    font-size: 1.3em;
    color: #1a1a1a;
    font-weight: 600;
}

.lesson-status {
    padding: 6px 16px;
    font-size: 0.9em;
    font-weight: 600;
    background: #e5e7eb;
    color: #6b7280;
}

.lesson-status.completed {
    background: #d1fae5;
    color: #065f46;
}

.lesson-status.locked {
    background: #dbeafe;
    color: #006699;
}

.lesson-content {
    padding: 30px;
}

.lesson-content p {
    margin-bottom: 15px;
    font-size: 1.05em;
    line-height: 1.7;
    color: #000000;
}

.lesson-content strong {
    color: #00d9ff;
    font-weight: 600;
}

.concept-box,
.formula-box,
.example-box {
    background: #f9fafb;
    padding: 20px;
    margin: 20px 0;
    border-left: 4px solid #00d9ff;
}

.concept-box h3,
.formula-box h3,
.example-box h3 {
    color: #000000;
    margin-bottom: 15px;
    font-size: 1.2em;
}

.concept-box ul,
.formula-box ul,
.example-box ul {
    margin-left: 20px;
}

.concept-box li,
.formula-box li,
.example-box li {
    margin-bottom: 10px;
    line-height: 1.6;
    color: #000000;
}

.formula {
    font-family: 'Courier New', monospace;
    font-size: 1.1em;
    background: white;
    padding: 15px;
    margin: 10px 0;
    color: #00d9ff;
    font-weight: 600;
    text-align: center;
}

.activation-item {
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid #e5e7eb;
}

.activation-item:last-child {
    border-bottom: none;
}

.activation-item h4 {
    color: #00d9ff;
    margin-bottom: 8px;
    font-size: 1.1em;
}

.complete-btn {
    background: #00d9ff;
    color: white;
    padding: 12px 30px;
    font-size: 1em;
    font-weight: 600;
    border: none;
    cursor: pointer;
    margin-top: 20px;
    transition: background 0.3s ease;
    font-family: 'Inter', sans-serif;
}

.complete-btn:hover {
    background: #0099cc;
}

.complete-btn:disabled {
    background: #9ca3af;
    cursor: not-allowed;
}

.playground {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-top: 20px;
}

.playground p,
.playground label,
.playground h3,
.playground h4 {
    color: #000000 !important;
}

.controls-section,
.visualization-section {
    background: #f9fafb;
    padding: 20px;
}

.controls-section h3,
.visualization-section h3 {
    color: #1a1a1a;
    margin-bottom: 20px;
    font-size: 1.2em;
    text-align: center;
}

.control-group {
    margin-bottom: 20px;
}

.control-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #000000;
}

.control-group input[type="range"] {
    width: 70%;
    height: 8px;
    background: #e5e7eb;
    outline: none;
    margin-right: 10px;
    -webkit-appearance: none;
    appearance: none;
}

.control-group input[type="range"]::-webkit-slider-track {
    width: 100%;
    height: 8px;
    background: #e5e7eb;
    border: none;
}

.control-group input[type="range"]::-moz-range-track {
    width: 100%;
    height: 8px;
    background: #e5e7eb;
    border: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: #00d9ff;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 10px rgba(0, 217, 255, 0.5);
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: #00d9ff;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 10px rgba(0, 217, 255, 0.5);
}

.control-group span {
    display: inline-block;
    min-width: 50px;
    font-weight: 600;
    color: #00d9ff;
}

.control-group select {
    width: 100%;
    padding: 10px;
    font-size: 1em;
    border: 2px solid #e5e7eb;
    background: white;
    font-family: 'Inter', sans-serif;
    color: #000000;
}

.control-group select:focus {
    outline: none;
    border-color: #00d9ff;
}

#neuronCanvas {
    width: 100%;
    height: auto;
    background: white;
    display: block;
    margin-bottom: 20px;
}

.calculation-display {
    background: white;
    padding: 20px;
}

.calculation-display h4 {
    color: #1a1a1a;
    margin-bottom: 15px;
    font-size: 1.1em;
}

.calc-step {
    font-family: 'Courier New', monospace;
    font-size: 0.95em;
    margin-bottom: 8px;
    color: #000000;
    line-height: 1.8;
}

.output-display {
    background: #f9fafb;
    padding: 15px;
    margin-top: 20px;
    text-align: center;
}

.final-result {
    font-size: 2em;
    font-weight: 700;
    color: #00d9ff;
    margin-top: 10px;
}

.challenge-explanation {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2ff 100%);
    border: 3px solid #00d9ff;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.3);
}

.challenge-explanation h3 {
    color: #000000;
    font-size: 1.4em;
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 800;
    text-shadow: 1px 1px 0px #00d9ff;
}

.challenge-explanation h4 {
    color: #000000;
    font-size: 1.1em;
    margin: 20px 0 10px 0;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.challenge-steps ol {
    margin-left: 20px;
    color: #000000;
}

.challenge-steps li {
    margin-bottom: 12px;
    line-height: 1.6;
    color: #000000;
}

.challenge-steps li strong {
    color: #00d9ff;
    font-weight: 700;
}

.challenge-goal {
    background: #ffffff;
    border: 2px solid #00d9ff;
    padding: 15px;
    margin-top: 20px;
}

.challenge-goal h4 {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.challenge-goal h4 button {
    transition: all 0.3s ease;
}

.challenge-goal h4 button:hover {
    transform: scale(1.05);
    box-shadow: 0 0 15px rgba(0, 217, 255, 0.5);
}

.challenge-goal p {
    color: #000000;
    margin: 0;
    font-weight: 600;
}

.python-section {
    background: linear-gradient(135deg, #000000 0%, #1a1a2e 100%);
    border: 3px solid #00d9ff;
    padding: 25px;
    margin-top: 30px;
    color: #ffffff;
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.4);
}

.python-section p {
    color: #ffffff !important;
    margin-bottom: 15px;
}

.python-section h4,
.python-section h5 {
    color: #00ffff;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 800;
    margin-bottom: 15px;
}

.python-section h5 {
    font-size: 1em;
    margin-top: 20px;
    margin-bottom: 10px;
}

.python-code {
    background: #0a0a0a;
    border: 2px solid #00ff00;
    margin: 15px 0;
    overflow-x: auto;
}

.python-code pre {
    margin: 0;
    padding: 20px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    line-height: 1.4;
    color: #00ff00;
    background: transparent;
}

.python-code code {
    color: #00ff00;
    text-shadow: 0 0 2px #00ff00;
}

.test-online {
    background: rgba(0, 217, 255, 0.1);
    border: 2px solid #00d9ff;
    padding: 20px;
    margin-top: 20px;
}

.test-online h5 {
    color: #00d9ff;
    font-size: 1.2em;
    margin-bottom: 10px;
}

.test-online p {
    color: #ffffff !important;
    margin-bottom: 10px;
}

.test-online strong {
    color: #00ff00;
}

.online-editor-link {
    display: inline-block;
    background: #00d9ff;
    color: #000000;
    padding: 12px 20px;
    text-decoration: none;
    font-weight: 700;
    margin: 10px 0;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.online-editor-link:hover {
    background: #ffffff;
    color: #000000;
    box-shadow: 0 0 15px #00d9ff;
}

.test-instructions {
    color: #ffffff !important;
    font-style: italic;
    margin-top: 10px;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #000000 0%, #1a0033 50%, #000033 100%);
    overflow-y: auto;
    animation: bgPulse 5s infinite alternate;
}

@keyframes bgPulse {
    0% { background-position: 0% 50%; }
    100% { background-position: 100% 50%; }
}

.modal-content {
    background: linear-gradient(135deg, #ffffff 0%, #e0f2ff 100%);
    margin: 20px auto;
    padding: 40px;
    width: 90%;
    max-width: 900px;
    box-shadow: 0 0 40px #00ffff, 0 0 80px #ff00ff, 0 0 120px rgba(0, 255, 255, 0.3);
    border: 4px solid #000000;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: borderGlow 2s infinite alternate;
}

@keyframes borderGlow {
    0% { box-shadow: 0 0 40px #00ffff, 0 0 80px #ff00ff, 0 0 120px rgba(0, 255, 255, 0.3); }
    100% { box-shadow: 0 0 60px #ff00ff, 0 0 100px #00ffff, 0 0 140px rgba(255, 0, 255, 0.3); }
}

.close-x {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 40px;
    font-weight: bold;
    color: #ff00ff;
    cursor: pointer;
    line-height: 1;
    transition: all 0.3s ease;
    text-shadow: 0 0 10px #ff00ff, 0 0 20px #ff00ff, 2px 2px 0px #00ffff;
    animation: xPulse 1.5s infinite;
}

@keyframes xPulse {
    0%, 100% { text-shadow: 0 0 10px #ff00ff, 0 0 20px #ff00ff, 2px 2px 0px #00ffff; }
    50% { text-shadow: 0 0 20px #00ffff, 0 0 30px #00ffff, 2px 2px 0px #ff00ff; }
}

.close-x:hover {
    color: #00ffff;
    transform: scale(1.3) rotate(180deg);
    text-shadow: 0 0 20px #00ffff, 0 0 40px #00ffff, 0 0 60px #ff00ff;
}

.modal-content h2 {
    text-align: center;
    color: #000000;
    font-size: 2.5em;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 5px;
    font-weight: 900;
    position: relative;
    text-shadow: 3px 3px 0px #00ffff, -3px -3px 0px #ff00ff, 0 0 20px rgba(0, 255, 255, 0.5);
    animation: titleGlitch 3s infinite;
}

@keyframes titleGlitch {
    0%, 90%, 100% { 
        text-shadow: 3px 3px 0px #00ffff, -3px -3px 0px #ff00ff, 0 0 20px rgba(0, 255, 255, 0.5);
    }
    92% {
        text-shadow: -3px -3px 0px #00ffff, 3px 3px 0px #ff00ff, 0 0 30px rgba(255, 0, 255, 0.5);
    }
    94% {
        text-shadow: 3px -3px 0px #ff00ff, -3px 3px 0px #00ffff, 0 0 25px rgba(0, 255, 255, 0.5);
    }
}

.modal-content > p {
    text-align: center;
    font-size: 1.2em;
    margin-bottom: 30px;
    color: #333333;
    font-weight: 500;
}

.challenge-section {
    background: linear-gradient(135deg, #1a1a1a, #2d2d2d);
    border: 2px solid #00d9ff;
    padding: 30px;
    margin: 30px 0;
    text-align: center;
    box-shadow: 
        0 0 30px rgba(0, 217, 255, 0.3),
        inset 0 0 30px rgba(0, 217, 255, 0.1);
}

.challenge-part {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid #333;
    margin: 20px 0;
    padding: 20px;
    border-left: 4px solid #00d9ff;
}

.challenge-part p {
    color: #ffffff !important;
}

.challenge-part h4 {
    color: #00d9ff;
    margin-bottom: 15px;
    font-size: 1.2em;
}

.python-test-case {
    background: #000;
    border: 1px solid #00d9ff;
    padding: 15px;
    margin: 15px 0;
    font-family: 'Courier New', monospace;
    color: #00d9ff;
    text-align: left;
}

.code-requirement {
    background: #000;
    border: 2px solid #00d9ff;
    padding: 15px;
    margin: 15px 0;
}

.code-requirement p,
.code-requirement textarea {
    color: #00d9ff !important;
}

@keyframes sectionFloat {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-5px); }
}

.challenge-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(45deg, transparent 48%, #00ffff 49%, #00ffff 51%, transparent 52%),
        linear-gradient(-45deg, transparent 48%, #ff00ff 49%, #ff00ff 51%, transparent 52%);
    background-size: 15px 15px;
    opacity: 0.05;
    pointer-events: none;
    animation: patternMove 20s linear infinite;
}

@keyframes patternMove {
    0% { background-position: 0 0, 0 0; }
    100% { background-position: 100px 100px, -100px -100px; }
}

.challenge-section h3 {
    color: #ffffff;
    font-size: 1.8em;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 4px;
    font-weight: 900;
    text-shadow: 3px 3px 0px #00ffff, -2px -2px 0px #ff00ff;
    animation: headerPulse 2s infinite;
}

@keyframes headerPulse {
    0%, 100% { 
        text-shadow: 3px 3px 0px #00ffff, -2px -2px 0px #ff00ff;
    }
    50% { 
        text-shadow: 3px 3px 0px #ff00ff, -2px -2px 0px #00ffff;
    }
}

.challenge-section p {
    color: #ffffff !important;
    margin-bottom: 20px;
    line-height: 1.8;
    font-weight: 500;
}

.challenge-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    margin: 20px 0;
}

.challenge-box {
    background: #ffffff;
    border: 3px solid #000000;
    padding: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 4px 4px 0px #00ffff;
    position: relative;
    overflow: hidden;
}

.challenge-box::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, #00ffff, #ff00ff, #00ffff);
    z-index: -1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.challenge-box:hover {
    background: #f0f0f0;
    box-shadow: 6px 6px 0px #ff00ff, 0 0 20px rgba(255, 0, 255, 0.3);
    transform: translate(-2px, -2px);
}

.challenge-box:hover::before {
    opacity: 0.1;
}

.challenge-box.selected {
    background: #000000;
    color: #ffffff;
    box-shadow: 0 0 20px #00ffff, 0 0 40px #ff00ff;
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 20px #00ffff, 0 0 40px #ff00ff;
    }
    50% {
        box-shadow: 0 0 30px #00ffff, 0 0 60px #ff00ff;
    }
}

.challenge-box.correct {
    background: #00ff00;
    color: #000000;
    border-color: #000000;
    box-shadow: 0 0 20px #00ff00, 0 0 40px #00ff00;
    animation: correctPulse 0.5s ease;
}

@keyframes correctPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.challenge-box.incorrect {
    background: #0080ff;
    color: #ffffff;
    border-color: #000000;
    box-shadow: 0 0 20px #0080ff, 0 0 40px #0080ff;
    animation: shake 0.5s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.challenge-label {
    font-size: 0.9em;
    color: #666666;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.challenge-box.selected .challenge-label {
    color: #cccccc;
}

.challenge-value {
    font-size: 1.3em;
    font-weight: 700;
    color: #000000;
}

.challenge-box.selected .challenge-value {
    color: #ffffff;
}

.challenge-instruction {
    color: #ffffff !important;
    font-size: 1.1em;
    margin: 20px 0;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.challenge-code {
    font-family: 'Courier New', monospace;
    background: #000000;
    color: #00ff00;
    padding: 20px;
    margin: 15px 0;
    border: 3px solid #00ff00;
    font-size: 1.1em;
    letter-spacing: 2px;
    box-shadow: 0 0 20px rgba(0, 255, 0, 0.3), inset 0 0 20px rgba(0, 255, 0, 0.1);
    text-shadow: 0 0 5px #00ff00;
}

.challenge-attempts {
    color: #00ffff !important;
    font-size: 1em;
    margin-top: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.verify-btn {
    background: #000000;
    color: #00ffff;
    padding: 15px 50px;
    font-size: 1.1em;
    font-weight: 900;
    border: 3px solid #00ffff;
    cursor: pointer;
    margin-top: 20px;
    font-family: 'Inter', sans-serif;
    text-transform: uppercase;
    letter-spacing: 3px;
    transition: all 0.3s ease;
    box-shadow: 4px 4px 0px #00ffff, 0 0 20px rgba(0, 255, 255, 0.3);
    position: relative;
}

.verify-btn:hover {
    background: #00ffff;
    color: #000000;
    box-shadow: 6px 6px 0px #ff00ff, 0 0 30px rgba(0, 255, 255, 0.5), 0 0 40px rgba(255, 0, 255, 0.3);
    transform: translate(-2px, -2px);
}

.verify-btn:active {
    transform: translate(2px, 2px);
    box-shadow: 2px 2px 0px #00ffff;
}

.verify-btn:disabled {
    background: #666666;
    color: #cccccc;
    border-color: #999999;
    cursor: not-allowed;
    box-shadow: none;
}

.certificate {
    background: linear-gradient(135deg, #ffffff 0%, #f5f5f5 100%);
    padding: 30px;
    border: 3px solid #000000;
    text-align: center;
    margin-bottom: 20px;
    box-shadow: 6px 6px 0px #00ffff, -6px -6px 0px #ff00ff;
    display: none;
    position: relative;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    transform: scale(0.85);
    transform-origin: top center;
}

.certificate::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    bottom: 10px;
    border: 2px solid #000000;
    pointer-events: none;
}

.certificate.revealed {
    display: block;
    animation: certReveal 0.8s ease;
}

@keyframes certReveal {
    0% {
        opacity: 0;
        transform: scale(0.8);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

.cert-logo {
    max-width: 100px;
    height: auto;
    margin-bottom: 20px;
}

.certificate h3 {
    font-size: 1.6em;
    color: #1a1a1a;
    margin-bottom: 20px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.cert-text {
    font-size: 0.95em;
    color: #6b7280;
    margin: 8px 0;
}

.cert-name {
    font-size: 1.6em;
    color: #00d9ff;
    font-weight: 700;
    margin: 15px 0;
    font-style: italic;
}

.cert-course {
    font-size: 1.2em;
    color: #1a1a1a;
    font-weight: 600;
    margin: 15px 0;
}

.cert-date {
    font-size: 0.9em;
    color: #6b7280;
    margin: 15px 0;
}

.cert-footer {
    font-size: 0.8em;
    color: #9ca3af;
    margin-top: 20px;
    font-weight: 500;
}

.download-btn,
.close-btn {
    padding: 12px 30px;
    font-size: 0.95em;
    font-weight: 700;
    border: 2px solid #000000;
    cursor: pointer;
    margin: 8px;
    font-family: 'Inter', sans-serif;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 2px;
    position: relative;
}

.download-btn {
    background: #000000;
    color: #00ff00;
    box-shadow: 4px 4px 0px #00ff00;
    border-color: #00ff00;
}

.download-btn:hover {
    background: #00ff00;
    color: #000000;
    box-shadow: 6px 6px 0px #000000, 0 0 20px rgba(0, 255, 0, 0.5);
    transform: translate(-2px, -2px);
}

.close-btn {
    background: #ffffff;
    color: #000000;
    box-shadow: 4px 4px 0px #ff00ff;
    border-color: #ff00ff;
}

.close-btn:hover {
    background: #ff00ff;
    color: #ffffff;
    box-shadow: 6px 6px 0px #000000, 0 0 20px rgba(255, 0, 255, 0.5);
    transform: translate(-2px, -2px);
}

footer {
    text-align: center;
    padding: 30px 20px;
    background: white;
    margin-top: 40px;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

footer p {
    color: #6b7280;
    margin-bottom: 5px;
}

.footer-tag {
    font-size: 0.9em;
    color: #9ca3af;
    font-weight: 500;
}

@media (max-width: 768px) {
    /* Global text fixes for mobile */
    body {
        overflow-x: hidden;
        word-wrap: break-word;
        overflow-wrap: break-word;
    }
    
    /* Prevent text overflow */
    * {
        word-wrap: break-word;
        overflow-wrap: break-word;
        hyphens: auto;
    }
    
    /* Header adjustments */
    header h1 {
        font-size: 1.5em;
        letter-spacing: 1px;
        word-wrap: break-word;
    }
    
    .subtitle {
        font-size: 0.9em;
    }
    
    /* Container fixes */
    .container {
        padding: 10px;
        max-width: 100%;
    }
    
    /* Lesson content */
    .lesson-header h2 {
        font-size: 1.1em;
        word-wrap: break-word;
    }
    
    .lesson-content {
        padding: 15px;
    }
    
    /* Playground - stack vertically */
    .playground {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    #neuronCanvas {
        max-width: 100%;
        height: auto;
    }
    
    /* Code blocks */
    pre, code {
        white-space: pre-wrap !important;
        word-wrap: break-word !important;
        overflow-wrap: break-word !important;
        max-width: 100%;
        overflow-x: auto;
    }
    
    .python-code pre code {
        font-size: 0.75em;
        line-height: 1.4;
    }
    
    /* Textareas */
    textarea {
        font-size: 0.8em !important;
        width: 100% !important;
        max-width: 100% !important;
    }
    
    /* Links - break long URLs */
    a {
        word-wrap: break-word;
        overflow-wrap: break-word;
        word-break: break-all;
    }
    
    /* Modal */
    .modal-content {
        width: 95%;
        padding: 15px;
        margin: 10px auto;
        max-width: 95vw;
    }
    
    .modal-content h2 {
        font-size: 1.5em;
        letter-spacing: 2px;
    }
    
    /* Challenge section */
    .challenge-section {
        padding: 15px;
        margin: 15px 0;
    }
    
    .challenge-section h3 {
        font-size: 1.3em;
        letter-spacing: 2px;
    }
    
    .challenge-part {
        padding: 15px;
        margin: 15px 0;
    }
    
    .challenge-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    .challenge-box {
        padding: 15px;
    }
    
    /* Python test case */
    .python-test-case {
        padding: 10px;
        font-size: 0.85em;
    }
    
    .code-requirement {
        padding: 10px;
    }
    
    /* Buttons */
    button {
        padding: 10px 15px !important;
        font-size: 0.9em !important;
        white-space: normal;
        word-wrap: break-word;
    }
    
    /* Input fields */
    input[type="number"] {
        width: 150px !important;
        font-size: 1em !important;
    }
    
    /* Certificate */
    .certificate {
        padding: 20px 15px;
    }
    
    .cert-logo {
        max-width: 80px;
    }
    
    .certificate h3 {
        font-size: 1.3em;
    }
    
    .cert-name {
        font-size: 1.3em;
    }
    
    .cert-course {
        font-size: 1.1em;
    }
    
    /* Formula and code displays */
    .formula,
    .challenge-code {
        font-size: 0.85em;
        padding: 10px;
        overflow-x: auto;
    }
    
    /* Test online section */
    .test-online {
        padding: 15px;
    }
    
    .online-editor-link {
        padding: 10px 15px;
        font-size: 0.85em;
        word-break: break-all;
    }
    
    /* Challenge explanation */
    .challenge-explanation {
        padding: 15px;
    }
    
    .challenge-explanation h3 {
        font-size: 1.2em;
    }
    
    /* Step instructions */
    .challenge-steps ol {
        padding-left: 20px;
    }
    
    .challenge-steps li {
        font-size: 0.9em;
        margin-bottom: 10px;
    }
}

/* Extra small devices */
@media (max-width: 480px) {
    header h1 {
        font-size: 1.2em;
        letter-spacing: 0px;
    }
    
    .subtitle {
        font-size: 0.8em;
    }
    
    .modal-content {
        padding: 10px;
    }
    
    .modal-content h2 {
        font-size: 1.2em;
        letter-spacing: 1px;
    }
    
    .challenge-section h3 {
        font-size: 1.1em;
        letter-spacing: 1px;
    }
    
    button {
        font-size: 0.85em !important;
        padding: 8px 12px !important;
    }
    
    input[type="number"] {
        width: 120px !important;
    }
    
    textarea {
        font-size: 0.7em !important;
    }
    
    .python-code pre code {
        font-size: 0.65em;
    }
}