@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,100..800;1,100..800&display=swap');

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

body {
    font-family: 'JetBrains Mono', 'Roboto', monospace;
    background: #0a0a0a;
    color: #e5e5e5;
    line-height: 1.6;
    overflow-x: hidden;
    background-attachment: fixed;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 4px;
    background: linear-gradient(90deg, #00d4ff, #007acc, #005999);
    z-index: 1000;
    transition: width 0.1s ease;
}

header {
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 100%);
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

header .container {
    position: relative;
    z-index: 1;
}

header h1 {
    font-size: 3.5rem;
    font-weight: 300;
    margin-bottom: 20px;
    color: #ffffff;
    letter-spacing: -0.02em;
    text-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
}

header p {
    font-size: 1.3rem;
    color: #b0b0b0;
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
    opacity: 0;
    animation: fadeInUp 1s ease-out 0.5s forwards;
}


@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    padding: 100px 0;
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.section.fade-in {
    opacity: 1;
    transform: translateY(0);
}

.section:nth-child(even) {
    background: rgba(255, 255, 255, 0.02);
}

.section h2 {
    font-size: 2.5rem;
    font-weight: 300;
    margin-bottom: 50px;
    text-align: center;
    color: #ffffff;
    letter-spacing: -0.01em;
    position: relative;
}

.section h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, #00d4ff, #007acc);
    border-radius: 1px;
}

.preface p {
    font-size: 1.2rem;
    font-weight: 300;
    max-width: 800px;
    margin: 0 auto 40px;
    text-align: center;
    line-height: 1.7;
    color: #c0c0c0;
}

.chapters {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 40px;
    margin-top: 60px;
}

.chapter {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    padding: 40px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    position: relative;
    overflow: hidden;
}

.chapter::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

.chapter:hover::before {
    left: 100%;
}

.chapter:hover {
    transform: translateY(-8px);
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(0, 212, 255, 0.3);
    box-shadow: 0 15px 35px rgba(0, 212, 255, 0.1);
}

.chapter h3 {
    font-size: 1.6rem;
    font-weight: 400;
    margin-bottom: 16px;
    color: #ffffff;
    transition: color 0.3s ease;
}

.chapter:hover h3 {
    color: #00d4ff;
}

.chapter p {
    margin-bottom: 24px;
    color: #a0a0a0;
    font-weight: 300;
    transition: color 0.3s ease;
}

.chapter:hover p {
    color: #c0c0c0;
}

.btn {
    display: inline-block;
    background: linear-gradient(135deg, #00d4ff, #007acc);
    color: #ffffff;
    padding: 14px 28px;
    text-decoration: none;
    border-radius: 8px;
    border: none;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    font-weight: 400;
    font-size: 0.95rem;
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.3);
}

.notes ul {
    max-width: 700px;
    margin: 0 auto;
    list-style: none;
    padding-left: 0;
}

.notes li {
    font-size: 1.1rem;
    font-weight: 300;
    margin-bottom: 20px;
    padding-left: 30px;
    position: relative;
    color: #b0b0b0;
}

.notes li::before {
    content: '';
    position: absolute;
    left: 0;
    color: #00d4ff;
    font-weight: bold;
    font-size: 1.2rem;
}

footer {
    background: rgba(255, 255, 255, 0.02);
    backdrop-filter: blur(10px);
    padding: 60px 0;
    text-align: center;
    color: #808080;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

footer a {
    color: #00d4ff;
    text-decoration: none;
    transition: color 0.2s ease;
    font-weight: 300;
}

footer a:hover {
    color: #ffffff;
}


body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 20%, rgba(0, 212, 255, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 122, 204, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}


code, pre {
    font-family: 'JetBrains Mono', monospace;
    background: rgba(255, 255, 255, 0.05);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.9em;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2.5rem;
    }

    .section h2 {
        font-size: 2rem;
    }

    .chapters {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .chapter {
        padding: 30px;
    }
}

.modern-input {
    border: 2px solid #e0e0e0;
    background:
        radial-gradient(circle at 20% 20%, rgba(53, 31, 74, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 122, 204, 0.03) 0%, transparent 50%);
    border-radius: 8px;
    padding: 12px 15px;
    font-size: 16px;
    width: 300px;
    transition: all 0.3s ease;
    outline: none; 
    color: white;
    
  }
.modern-input:focus {
    border-color: #007bff;
    box-shadow: 0 0 8px rgba(0, 123, 255, 0.2);
  }

.feedbackContainer {
    flex-direction: column;
    gap: 15px;
    display: flex;           
    justify-content: center; 
    align-items: center;  
}



  .stars {
    display: flex;
    flex-direction: row-reverse;
    justify-content: center;
    gap: 5px;
  }

  .stars input {
    display: none;
  }

  .stars label {
    font-size: 4rem; 
    color: lightgray;
    cursor: pointer;
    transition: color 0.2s, transform 0.2s;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    border-radius: 30%; 
    padding: 0.1em; 
    text-shadow: 1px 1px 3px rgba(0,0,0,0.2); 
  }

  
  .stars label:hover,
  .stars label:hover ~ label {
    color: gold;
    transform: scale(1.1); 
  }

  .stars input:checked ~ label {
    color: gold;
  }