:root {
    /* New Dark Modern Color Palette */
    --primary-dark: #0a192f;     /* Navy blue */
    --primary: #172a45;         /* Darker blue */
    --secondary: #64ffda;       /* Teal accent */
    --accent: #8892b0;          /* Light gray-blue */
    --light: #ccd6f6;           /* Off-white text */
    --dark: #020c1b;            /* Almost black */
    --text-color: #e6f1ff;      /* Bright text */
    --border-radius: 8px;
    --card-bg: #112240;         /* Card background */
    --hover-bg: #233554;        /* Hover state */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Calibre', 'Inter', sans-serif;
}

body {
    background-color: var(--primary-dark);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

/* Top Ribbon - Dark Theme */
.top-ribbon {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--primary);
    color: var(--light);
    box-shadow: 0 4px 12px rgba(2, 12, 27, 0.7);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(100, 255, 218, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo img {
    height: 40px;
    filter: brightness(0) invert(1);
}

.main-nav {
    display: flex;
    gap: 1.5rem;
}

.main-nav a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
    font-size: 0.95rem;
}

.main-nav a:hover, .main-nav a.active {
    color: var(--secondary);
    background-color: rgba(100, 255, 218, 0.1);
}

.top-ad {
    min-width: 300px;
    text-align: center;
}

/* Container Layout */
.container {
    display: flex;
    min-height: calc(100vh - 72px);
}

/* Sidebar - Dark Theme */
.sidebar {
    width: 300px;
    background-color: var(--primary);
    padding: 1.5rem;
    box-shadow: 4px 0 10px rgba(2, 12, 27, 0.5);
    overflow-y: auto;
    border-right: 1px solid rgba(100, 255, 218, 0.1);
}

.search-box {
    display: flex;
    margin-bottom: 1.5rem;
    position: relative;
}

.search-box input {
    flex: 1;
    padding: 0.75rem 1rem;
    background-color: var(--primary-dark);
    border: 1px solid var(--accent);
    border-radius: var(--border-radius);
    color: var(--light);
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: var(--secondary);
    box-shadow: 0 0 0 2px rgba(100, 255, 218, 0.3);
}

.search-box button {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    color: var(--accent);
    cursor: pointer;
}

.search-box button:hover {
    color: var(--secondary);
}

.calculator-categories {
    margin-bottom: 1.5rem;
}

.category {
    margin-bottom: 1rem;
    border: 1px solid rgba(136, 146, 176, 0.2);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: all 0.3s ease;
}

.category:hover {
    border-color: var(--secondary);
}

.category-header {
    display: flex;
    align-items: center;
    padding: 1rem;
    background-color: var(--card-bg);
    cursor: pointer;
    user-select: none;
    transition: all 0.3s ease;
}

.category-header:hover {
    background-color: var(--hover-bg);
}

.category-header h3 {
    flex: 1;
    margin-left: 0.75rem;
    font-size: 1rem;
    font-weight: 500;
    color: var(--light);
}

.category-header i {
    transition: all 0.3s ease;
    color: var(--accent);
}

.category.active .category-header i:last-child {
    transform: rotate(180deg);
    color: var(--secondary);
}

.calculator-list {
    list-style: none;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background-color: var(--primary-dark);
}

.category.active .calculator-list {
    max-height: 1000px;
}

.calculator-list li {
    padding: 0.75rem 1rem 0.75rem 3rem;
    border-top: 1px solid rgba(136, 146, 176, 0.1);
    transition: all 0.2s ease;
}

.calculator-list li:hover {
    background-color: var(--hover-bg);
}

.calculator-list a {
    color: var(--accent);
    text-decoration: none;
    display: block;
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

.calculator-list a:hover {
    color: var(--secondary);
}

.calculator-list sub {
    font-size: 0.7em;
    vertical-align: sub;
    color: var(--secondary);
}

.sidebar-ad {
    margin-top: 1.5rem;
    padding: 1rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid rgba(136, 146, 176, 0.2);
}

/* Main Content - Dark Theme */
.content {
    flex: 1;
    padding: 2rem;
    background-color: var(--primary-dark);
}

.welcome-message {
    margin-bottom: 2rem;
}

.welcome-message h2 {
    color: var(--light);
    margin-bottom: 1rem;
    font-size: 2rem;
    font-weight: 600;
}

.welcome-message p {
    color: var(--accent);
    max-width: 800px;
    line-height: 1.7;
}

.featured-calculators h3 {
    margin: 2rem 0 1.5rem;
    color: var(--light);
    font-size: 1.3rem;
    font-weight: 500;
    position: relative;
    padding-bottom: 0.5rem;
}

.featured-calculators h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 2px;
    background-color: var(--secondary);
}

.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.calculator-card {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    padding: 1.5rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--light);
    transition: all 0.3s ease;
    border: 1px solid rgba(136, 146, 176, 0.1);
    height: 100%;
}

.calculator-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(2, 12, 27, 0.5);
    border-color: var(--secondary);
}

.calculator-card i {
    font-size: 1.8rem;
    margin-bottom: 1.2rem;
    color: var(--secondary);
}

.calculator-card h4 {
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.calculator-card p {
    color: var(--accent);
    font-size: 0.9rem;
    line-height: 1.6;
}

.content-ad {
    margin: 3rem 0;
    padding: 1.5rem;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid rgba(136, 146, 176, 0.2);
}

/* Footer - Dark Theme */
.footer {
    background-color: var(--primary);
    color: var(--accent);
    padding: 2rem;
    text-align: center;
    border-top: 1px solid rgba(100, 255, 218, 0.1);
}

.footer p {
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--accent);
    text-decoration: none;
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

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

/* Ad Unit Styles */
.ad-unit {
    padding: 1.5rem;
    background-color: var(--primary-dark);
    border: 1px dashed var(--accent);
    color: var(--accent);
    border-radius: var(--border-radius);
    text-align: center;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .sidebar {
        width: 260px;
    }
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid rgba(100, 255, 218, 0.1);
    }
    
    .top-ribbon {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .main-nav {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .calculator-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 0.5rem;
    }
}
/* Compact Calculator Styles */
.compact-calculator {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid rgba(136, 146, 176, 0.2);
}

.calculator-header {
    margin-bottom: 1.5rem;
}

.calculator-header h2 {
    color: var(--secondary);
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.calculator-header p {
    color: var(--accent);
    font-family: monospace;
    font-size: 1.1rem;
    margin-top: 0.25rem;
}

.calculator-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.input-row {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.input-row label {
    width: 120px;
    color: var(--light);
    font-size: 0.95rem;
}

.input-row input {
    flex: 1;
    padding: 0.6rem 0.8rem;
    background-color: var(--primary-dark);
    border: 1px solid var(--accent);
    border-radius: var(--border-radius);
    color: var(--light);
    font-size: 0.95rem;
}

.calculate-button {
    background-color: var(--secondary);
    color: var(--primary-dark);
    border: none;
    padding: 0.75rem;
    font-weight: 600;
    border-radius: var(--border-radius);
    cursor: pointer;
    width: 100%;
    margin-top: 0.5rem;
    transition: all 0.2s;
}

.calculate-button:hover {
    background-color: transparent;
    color: var(--secondary);
    box-shadow: 0 0 0 1px var(--secondary);
}

.result-card {
    background-color: var(--primary-dark);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid rgba(100, 255, 218, 0.2);
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.result-value {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.result-label {
    color: var(--accent);
    font-size: 0.9rem;
}

.result-scale {
    margin-top: 1.5rem;
}

.scale-labels {
    display: flex;
    justify-content: space-between;
    color: var(--accent);
    font-size: 0.85rem;
    margin-bottom: 0.5rem;
}

.scale-bar {
    height: 8px;
    background: linear-gradient(to right, var(--secondary), #3a7ca5);
    border-radius: 4px;
    position: relative;
    margin-bottom: 0.3rem;
}

.scale-indicator {
    position: absolute;
    top: -6px;
    width: 6px;
    height: 20px;
    background-color: var(--light);
    transform: translateX(-50%);
    transition: left 0.3s ease;
}

.scale-markers {
    display: flex;
    justify-content: space-between;
    color: var(--accent);
    font-size: 0.8rem;
}

.calculator-info {
    background-color: var(--primary-dark);
    padding: 1.25rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(136, 146, 176, 0.2);
}

.calculator-info h3 {
    color: var(--secondary);
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.calculator-info ul {
    list-style-position: inside;
    color: var(--accent);
    font-size: 0.9rem;
}

.calculator-info li {
    margin-bottom: 0.3rem;
}

.calculator-info strong {
    color: var(--light);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }
    
    .input-row {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .input-row label {
        margin-bottom: 0.3rem;
        width: auto;
    }
    
    .input-row input {
        width: 100%;
    }
}
/* Additional Calculator Styles */
.input-options {
    display: flex;
    gap: 0.75rem;
    margin-top: 1rem;
}

.reset-button {
    background-color: transparent;
    color: var(--accent);
    border: 1px solid var(--accent);
    padding: 0.75rem;
    font-weight: 600;
    border-radius: var(--border-radius);
    cursor: pointer;
    flex: 1;
    transition: all 0.2s;
}

.reset-button:hover {
    background-color: rgba(136, 146, 176, 0.1);
    color: var(--light);
}

.relationship-box {
    background-color: var(--primary-dark);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-top: 1.5rem;
    border: 1px solid rgba(100, 255, 218, 0.2);
}

.relationship-box h4 {
    color: var(--light);
    margin-bottom: 0.75rem;
    font-size: 1rem;
}

.relationship-box p {
    color: var(--accent);
    margin-bottom: 0.5rem;
    font-family: monospace;
}

.formula-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.formula-card {
    background-color: var(--primary-dark);
    padding: 1rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(136, 146, 176, 0.2);
}

.formula-card p:first-child {
    color: var(--secondary);
    font-family: monospace;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.formula-card p:last-child {
    color: var(--accent);
    font-size: 0.85rem;
}
/* Additional Displacement Calculator Styles */
.unit-converter {
    background-color: var(--primary-dark);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-top: 1.5rem;
    border: 1px solid rgba(100, 255, 218, 0.2);
}

.unit-converter h4 {
    color: var(--light);
    margin-bottom: 1rem;
    font-size: 1rem;
}

.converter-option {
    display: flex;
    align-items: center;
    margin-bottom: 0.75rem;
}

.converter-option label {
    color: var(--accent);
    margin-right: 0.75rem;
    font-size: 0.9rem;
    width: 80px;
}

.converter-option select {
    flex: 1;
    padding: 0.5rem;
    background-color: var(--primary);
    border: 1px solid var(--accent);
    border-radius: var(--border-radius);
    color: var(--light);
    font-size: 0.9rem;
}

.converted-value {
    background-color: var(--primary);
    padding: 0.75rem;
    border-radius: var(--border-radius);
    text-align: center;
    font-family: monospace;
    font-size: 1.1rem;
    color: var(--secondary);
    border: 1px solid rgba(136, 146, 176, 0.2);
}

.result-card + .result-card {
    margin-top: 1.5rem;
}