:root {
    --primary-color: #4ECDC4;
    --primary-dark: #3aa8a1;
    --secondary-color: #FF6B6B;
    --dark-bg: #121212;
    --dark-gray: #1E1E1E;
    --medium-gray: #2C2C2C;
    --light-gray: #E0E0E0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 15px 30px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s ease-in-out;
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --border-radius-sm: 8px;
}

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

body {
    background: linear-gradient(135deg, var(--dark-bg), var(--dark-gray));
    color: var(--light-gray);
    font-family: 'Inter', sans-serif;
    min-height: 100vh;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
}

#particles-js {
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.back-button {
    background: rgba(255, 107, 107, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 107, 107, 0.2);
    border-radius: 8px;
    color: #E0E0E0;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 500;
    left: 15px;
    padding: 10px 12px;
    position: absolute; 
    text-decoration: none;
    top: 15px;
    transition: all 0.3s ease;
    z-index: 1000; 
}

.back-button:hover {
    background: rgba(255, 107, 107, 0.2);
    border: 1px solid rgba(255, 107, 107, 0.3);
}

.main-container {
    max-width: 1000px;
    margin: 60px auto 40px;
    position: relative;
    z-index: 1;
}

.about-sepad {
    background: rgba(30, 30, 30, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: var(--border-radius-lg);
    padding: 30px;
    margin-bottom: 30px;
    border: 1px solid rgba(78, 205, 196, 0.15);
    box-shadow: var(--shadow);
}

.about-sepad h1 {
    color: var(--primary-color);
    font-size: 2.2rem;
    margin-bottom: 20px;
    text-align: center;
}

.about-sepad p {
    color: var(--light-gray);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 15px;
    text-align: justify;
}

.downloads-section {
    background: rgba(30, 30, 30, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: var(--border-radius-lg);
    padding: 30px;
    margin-bottom: 30px;
    border: 1px solid rgba(78, 205, 196, 0.15);
    box-shadow: var(--shadow);
}

.downloads-section h2 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-bottom: 25px;
    text-align: center;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.download-card {
    background: rgba(44, 44, 44, 0.5);
    border-radius: var(--border-radius);
    padding: 20px;
    transition: var(--transition);
    border: 1px solid rgba(78, 205, 196, 0.1);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.download-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.download-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    flex-shrink: 0;
}

.pdf-icon { background: #FF6B6B; }
.word-icon { background: #2B579A; }
.video-icon { background: #FFBE0B; }
.ppt-icon { background: #D24726; }
.zip-icon { background: var(--primary-color); }

.download-info {
    flex: 1;
}

.download-info h3 {
    color: var(--primary-color);
    margin-bottom: 5px;
    font-size: 1.2rem;
}

.download-info p {
    color: var(--light-gray);
    opacity: 0.8;
    font-size: 0.9rem;
}

.download-description {
    color: var(--light-gray);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 15px;
    flex: 1;
}

.download-meta {
    display: flex;
    justify-content: space-between;
    color: var(--light-gray);
    font-size: 0.85rem;
    padding-top: 15px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.download-button {
    display: inline-block;
    background: var(--primary-color);
    color: var(--dark-bg);
    padding: 0.7rem;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    margin-top: 15px;
    text-align: center;
    width: 100%;
}

.download-button:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(78, 205, 196, 0.3);
}

.file-size, .file-format {
    display: flex;
    align-items: center;
    gap: 5px;
}

.team-section {
    background: rgba(30, 30, 30, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: var(--border-radius-lg);
    padding: 30px;
    border: 1px solid rgba(78, 205, 196, 0.15);
    box-shadow: var(--shadow);
}

.team-section h2 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-bottom: 25px;
    text-align: center;
}

.contribution-info {
    background: rgba(78, 205, 196, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 15px;
    max-width: 500px;
    margin: 0 auto 30px;
    border: 1px solid rgba(78, 205, 196, 0.2);
}

.equal-contribution {
    color: #E0E0E0;
    font-size: 0.9rem;
    margin-bottom: 8px;
    text-align: center;
}

.contribution-bar {
    background: rgba(44, 44, 44, 0.7);
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 5px;
    display: flex;
}

.bar-fill {
    height: 100%;
}

.bar-fill.abolfazl {
    background: linear-gradient(90deg, #4ECDC4, #3aa8a1);
    width: 50%;
}

.bar-fill.parsa {
    background: linear-gradient(90deg, #FF6B6B, #FF8E8E);
    width: 50%;
}

.contribution-names {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: #E0E0E0;
}

.team-members {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: center;
}

.member-card {
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    padding: 25px;
    width: calc(50% - 15px);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    min-height: 100%;
    display: flex;
    flex-direction: column;
}

.abolfazl-card {
    background: rgba(30, 30, 30, 0.7);
    border: 1px solid rgba(78, 205, 196, 0.15);
}

.parsa-card {
    background: rgba(30, 30, 30, 0.7);
    border: 1px solid rgba(255, 107, 107, 0.15);
}

.member-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.member-image {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 20px;
}

.abolfazl-card .member-image {
    border: 3px solid rgba(78, 205, 196, 0.3);
}

.parsa-card .member-image {
    border: 3px solid rgba(255, 107, 107, 0.3);
}

.member-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.member-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.member-info h3 {
    color: #4ECDC4;
    font-size: 1.5rem;
    margin-bottom: 10px;
    text-align: center;
}

.parsa-card h3 {
    color: #FF6B6B;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 15px;
    color: #B0B0B0;
}

.social-link a {
    color: #B0B0B0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.social-link a:hover {
    color: #4ECDC4;
}

.parsa-card .social-link a:hover {
    color: #FF6B6B;
}

.member-bio {
    color: #E0E0E0;
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 20px;
    text-align: center;
    flex: 1;
}

.contributions {
    background: rgba(44, 44, 44, 0.5);
    border-radius: 10px;
    padding: 15px;
}

.contributions h4 {
    color: #4ECDC4;
    font-size: 1.1rem;
    margin-bottom: 10px;
    text-align: center;
}

.parsa-card .contributions h4 {
    color: #FF6B6B;
}

.contributions ul {
    list-style-type: none;
    padding-left: 0;
}

.contributions li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.abolfazl-card .contributions li::before {
    color: #4ECDC4;
}

.parsa-card .contributions li::before {
    color: #FF6B6B;
}

.contributions li::before {
    content: '•';
    position: absolute;
    left: 0;
}

@media (max-width: 768px) {
    .main-container {
        padding: 0 15px;
    }
    
    .about-sepad h1,
    .downloads-section h2,
    .team-section h2 {
        font-size: 1.8rem;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .member-card {
        width: 100%;
        padding: 20px;
    }
    
    .member-image {
        width: 100px;
        height: 100px;
    }
}

@media (max-width: 480px) {
    .about-sepad h1,
    .downloads-section h2,
    .team-section h2 {
        font-size: 1.6rem;
    }
    
    .about-sepad,
    .downloads-section,
    .team-section {
        padding: 20px;
    }
    
    .member-card {
        padding: 15px;
    }
    
    .member-info h3 {
        font-size: 1.3rem;
    }
    
    .back-button {
        top: 10px;
        left: 10px;
        padding: 8px 10px;
        font-size: 13px;
    }
}