:root {
    --primary-color: #1a6fc9;
    --secondary-color: #0d8b8b;
    --accent-color: #4db8ff;
    --light-color: #e6f7ff;
    --dark-color: #003366;
}

.navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.nav-button {
    background: var(--accent-color);
    color: white;
    padding: 8px 20px;
    border-radius: 15px;
    text-decoration: none;
    transition: opacity 0.3s;
}

.nav-button-no {
    background: var();
    color: white;
    padding: 8px 20px;
    border-radius: 15px;
    text-decoration: none;
    transition: opacity 0.3s;
}

.nav-text{
    font-size: 1.5rem;
}

.nav-button:hover {
    opacity: 0.8;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f9fc;
    color: #333;
    line-height: 1.6;
    background-image: linear-gradient(to bottom, rgba(230, 247, 255, 0.8), rgba(245, 249, 252, 1)), url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path fill="%234db8ff" fill-opacity="0.1" d="M30,30 Q50,10 70,30 T90,50 Q70,70 50,90 T10,50 Q30,30 50,10 Z" /></svg>');
}

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

header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem 0;
    text-align: center;
    border-radius: 0 0 20px 20px;
    box-shadow: 0 4px 12px rgba(0, 51, 102, 0.2);
    position: relative;
    overflow: hidden;
}

header::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 10px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.7), transparent);
}

h1 {
    margin: 0;
    font-size: 2.5rem;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}

.content {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    margin-top: 40px;
}

.content-tasks {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    margin-top: 40px;
    margin-left: 10%;
    margin-right: 10%;
}

.main-content {
    flex: 1;
    min-width: 300px;
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    border-top: 5px solid var(--accent-color);
}

.sidebar {
    width: 300px;
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

h2 {
    color: var(--dark-color);
    border-bottom: 2px solid var(--light-color);
    padding-bottom: 10px;
    margin-top: 0;
}

h3 {
    color: var(--secondary-color);
    margin-top: 25px;
}

.chemical-formula {
    font-family: 'Courier New', monospace;
    background-color: var(--light-color);
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
    border-left: 4px solid var(--accent-color);
    overflow-x: auto;
    background-image: url('/GdS-Program/images/formula.svg');
    background-repeat: no-repeat;
    background-position: 50%;
    background-size: 10rem;
}

.chemical-title {
    font-weight: bold;
    color: var(--accent-color);
    margin-bottom: 5px;
}

.reaction {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 25px 0;
    flex-wrap: wrap;
    gap: 10px;
}

.reaction-part {
    padding: 10px 15px;
    background-color: var(--light-color);
    border-radius: 8px;
    text-align: center;
}

.reaction-arrow {
    font-size: 1.5rem;
    color: var(--secondary-color);
}

.example {
    background-color: #f0f9f9;
    padding: 15px;
    border-radius: 8px;
    margin: 15px 0;
    border-left: 3px solid var(--secondary-color);
    background-image: url('/GdS-Program/images/example.svg');
    background-repeat: no-repeat;
    background-position: 50%;
    background-size: 10rem;
}

.example-title {
    font-weight: bold;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.water-effect {
    position: relative;
    display: inline-block;
}

.water-effect::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
}

@keyframes wave {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

footer {
    text-align: center;
    margin-top: 50px;
    padding: 20px;
    color: #666;
    font-size: 0.9rem;
}

.nav-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 20px;
    background-color: rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.nav-links a:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-links2 {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
}

.nav-links2 a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 20px;
    background-color: rgba(0, 255, 0, 0.4);
    transition: all 0.3s ease;
}

.nav-links2 a:hover {
    background-color: rgba(0, 255, 0, 0.6);
    transform: translateY(-2px);
}

.nav-links3 {
    display: flex;
    justify-content: center;
    font-size: 1rem;
    gap: 20px;
    margin-top: 20px;
}

.nav-links3 a {
    color: white;
    text-decoration: none;
    padding: 8px 15px;
    border-radius: 20px;
    background-color: rgba(0, 255, 0, 0.4);
    transition: all 0.3s ease;
}

.nav-links3 a:hover {
    background-color: rgba(0, 255, 0, 0.6);
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .content {
        flex-direction: column;
    }
    
    .sidebar {
        width: auto;
    }
}

.answer-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin: 15px 0;
}

.input-group {
    display: flex;
    flex-direction: column;
    margin-right: 50px;
}

.input-label {
    font-size: 0.9em;
    margin-bottom: 5px;
    color: var(--secondary-color);
}

.answer-input {
    width: 100%;
    padding: 8px 12px;
    border: 2px solid var(--light-color);
    border-radius: 8px;
    font-size: 16px;
    min-height: 40px;
}

.code{
    background-color: #ccc;
    padding: 2.5px;
    border-radius: 5px;
}

p::first-letter {
    margin-left: 1.1rem;
}

.example-wrong {
    background-color: #f0f9f9;
    padding: 15px;
    padding-top: 1px;
    border-radius: 8px;
    margin: 15px 0;
    border-left: 5px solid #f00;
}

.example-wrong-title {
    font-weight: bold;
    color: #a00;
    margin-bottom: 10px;
}

.example-right {
    background-color: #f0f9f9;
    padding: 15px;
    padding-top: 1px;
    border-radius: 8px;
    margin: 15px 0;
    border-left: 5px solid #0f0;
}

.example-right-title {
    font-weight: bold;
    color: #0a0;
    margin-bottom: 10px;
}