:root {
    --primary-color: #2E5090;
    --secondary-color: #4A90E2;
    --accent-color: #00BFA5;
    --text-color: #333333;
    --text-light: #666666;
    --bg-light: #F5F5F5;
    --bg-white: #FFFFFF;
    --border-color: #E0E0E0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 20px rgba(0,0,0,0.15);
}

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

body {
    font-family: 'Open Sans', 'Segoe UI', sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    padding-top: 70px;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Roboto', 'Helvetica Neue', sans-serif;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 1rem;
}

/* Navigation */
.navbar {
    background-color: white !important;
    box-shadow: var(--shadow-sm);
    padding: 1rem 0;
    transition: all 0.3s ease;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color) !important;
}

.navbar-brand i {
    margin-right: 0.5rem;
}

.nav-link {
    color: var(--text-color) !important;
    font-weight: 500;
    margin: 0 0.5rem;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--secondary-color) !important;
}

.dropdown-menu {
    border: none;
    box-shadow: var(--shadow-md);
    border-radius: 8px;
}

.dropdown-item:hover {
    background-color: var(--bg-light);
    color: var(--secondary-color);
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: calc(100vh - 70px);
    display: flex;
    align-items: center;
    padding: 4rem 0;
}

.hero-section h1 {
    color: white;
}

.hero-section .lead {
    opacity: 0.95;
}

/* Feature Cards */
.feature-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.feature-icon i {
    font-size: 2rem;
    color: white;
}

/* Stat Cards */
.stat-card {
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-3px);
}

/* Content Sections */
.content-section {
    padding: 4rem 0;
}

.content-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
    border-top: 4px solid var(--secondary-color);
}

/* Molecule Page Specific */
.molecule-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 4rem 0;
    margin-bottom: 3rem;
}

.molecule-content {
    background: white;
    border-radius: 12px;
    padding: 3rem;
    box-shadow: var(--shadow-md);
}

.sidebar {
    position: sticky;
    top: 90px;
}

.sidebar-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.sidebar-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.sidebar-links {
    list-style: none;
    padding: 0;
}

.sidebar-links li {
    margin-bottom: 0.75rem;
}

.sidebar-links a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.sidebar-links a:hover {
    color: var(--secondary-color);
}

/* Tables */
.data-table {
    width: 100%;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.data-table thead {
    background: var(--primary-color);
    color: white;
}

.data-table th,
.data-table td {
    padding: 1rem;
    text-align: left;
}

.data-table tbody tr:nth-child(even) {
    background: var(--bg-light);
}

.data-table tbody tr:hover {
    background: #e8f4fd;
}

/* Buttons */
.btn-primary {
    background: var(--secondary-color);
    border: none;
    border-radius: 8px;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: #357ABD;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline-primary {
    color: var(--secondary-color);
    border: 2px solid var(--secondary-color);
    border-radius: 8px;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-outline-primary:hover {
    background: var(--secondary-color);
    color: white;
}

/* Forms */
.form-control {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 0.2rem rgba(74, 144, 226, 0.25);
}

/* Footer */
footer {
    background: #1a1a2e;
    color: #b0b0b0;
    padding: 3rem 0 2rem;
}

footer h5 {
    color: white;
    margin-bottom: 1rem;
}

footer a {
    color: #b0b0b0;
    text-decoration: none;
    transition: color 0.3s ease;
}

footer a:hover {
    color: var(--secondary-color);
}

.social-links a {
    font-size: 1.25rem;
}

/* Breadcrumbs */
.breadcrumb {
    background: none;
    padding: 0;
    margin-bottom: 2rem;
}

.breadcrumb-item a {
    color: var(--secondary-color);
    text-decoration: none;
}

.breadcrumb-item.active {
    color: var(--text-light);
}

/* Code Blocks */
.code-block {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    font-family: 'Roboto Mono', 'Courier New', monospace;
    overflow-x: auto;
}

/* Alert Boxes */
.alert-info {
    background: #e3f2fd;
    border-left: 4px solid var(--secondary-color);
    color: var(--primary-color);
}

.alert-success {
    background: #e8f5e9;
    border-left: 4px solid #4caf50;
    color: #2e7d32;
}

/* List Groups */
.list-group-item {
    border: 1px solid var(--border-color);
    margin-bottom: -1px;
    transition: all 0.3s ease;
}

.list-group-item:hover {
    background: var(--bg-light);
    border-color: var(--secondary-color);
}

/* Image Effects */
img {
    max-width: 100%;
    height: auto;
}

.rounded {
    border-radius: 12px;
}

.shadow-lg {
    box-shadow: var(--shadow-lg);
}

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

.fade-in-up {
    animation: fadeInUp 0.8s ease;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 2rem;
    }

    .feature-card {
        margin-bottom: 2rem;
    }

    .sidebar {
        position: relative;
        top: 0;
    }

    .navbar-nav {
        text-align: center;
    }

    .nav-link {
        margin: 0.25rem 0;
    }
}

@media (max-width: 576px) {
    body {
        padding-top: 60px;
    }

    .hero-section {
        min-height: 70vh;
    }

    .container {
        padding: 0 1rem;
    }

    .display-3 {
        font-size: 2rem;
    }

    .display-5 {
        font-size: 1.75rem;
    }
}

/* Utility Classes */
.text-gradient {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bg-gradient-primary {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
}

.border-top-accent {
    border-top: 4px solid var(--accent-color);
}

.hover-scale {
    transition: transform 0.3s ease;
}

.hover-scale:hover {
    transform: scale(1.05);
}

/* Loading Animation */
.molecular-spinner {
    width: 50px;
    height: 50px;
    position: relative;
    margin: 2rem auto;
}

.molecular-spinner::before,
.molecular-spinner::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--secondary-color);
    animation: orbit 2s linear infinite;
}

.molecular-spinner::after {
    animation-delay: -1s;
    background: var(--primary-color);
}

@keyframes orbit {
    0% { transform: rotate(0deg) translateX(25px) rotate(0deg); }
    100% { transform: rotate(360deg) translateX(25px) rotate(-360deg); }
}