/* Enhanced CSS Custom Properties for Better Theming */
:root {
    /* Color Palette */
    --primary-color: #4f46e5;
    --primary-hover: #3730a3;
    --secondary-color: #3730a3;
    --accent-color: #818cf8;
    --accent-light: #a5b4fc;
    
    /* Background Colors */
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --surface-alt: #f1f5f9;
    
    /* Text Colors */
    --text-color: #1e293b;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --text-inverse: #ffffff;
    
    /* Border Colors */
    --border-color: #e2e8f0;
    --border-focus: var(--primary-color);
    --border-hover: #cbd5e1;
    
    /* Status Colors */
    --success-color: #22c55e;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 10px 10px -5px rgb(0 0 0 / 0.04);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.4s ease;
    
    /* Typography */
    --font-family: 'Inter', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Legacy properties for backward compatibility */
    --card-shadow: var(--shadow-md);
    --hover-shadow: var(--shadow-lg);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.5;
    color: var(--text-color);
    background-color: var(--background-color);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    font-size: var(--font-size-base);
}

/* Visually hidden (for a11y, SEO rich results labels) */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Header Styles */
header {
    background-color: var(--surface-color);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.75rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo {
    font-size: clamp(1.25rem, 4vw, 1.5rem);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i {
    font-size: clamp(1.5rem, 4vw, 1.75rem);
}

.nav-links {
    display: flex;
    gap: clamp(1rem, 3vw, 2rem);
    align-items: center;
    flex-wrap: wrap;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
    font-size: clamp(0.875rem, 2.5vw, 1rem);
    padding: 0.5rem;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link.active {
    color: var(--primary-color);
}

.dropbtn.active {
    color: var(--primary-color);
}

/* Dropdown Styles */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropbtn {
    background: none;
    border: none;
    font-family: 'Inter', sans-serif;
    font-size: clamp(0.875rem, 2.5vw, 1rem);
    font-weight: 500;
    color: var(--text-color);
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: white;
    min-width: 200px;
    box-shadow: var(--card-shadow);
    border-radius: 0.5rem;
    z-index: 1;
    padding: 0.25rem 0;
    right: 0;
    max-height: 80vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

.dropdown-content a {
    color: var(--text-color);
    padding: 0.5rem 1rem;
    text-decoration: none;
    display: block;
    transition: background-color 0.2s;
    font-size: 0.95rem;
    line-height: 1.2;
    white-space: nowrap;
}

.dropdown-content a:hover {
    background-color: var(--background-color);
    color: var(--primary-color);
}

.dropdown-content a.active {
    color: var(--primary-color);
    background-color: var(--background-color);
}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown.active .dropdown-content {
    display: block;
}

.dropdown:hover .dropbtn {
    color: var(--primary-color);
}

.x-share {
    display: inline-flex !important;
    align-items: center;
    gap: 0.375rem;
    color: #536471;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.x-share:hover {
    color: #1d9bf0;
}

.x-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

/* Main Content Styles */
main {
    max-width: 1200px;
    margin: 1rem auto;
    padding: 0 1rem;
}

.hero-section {
    text-align: center;
    margin-bottom: 2rem;
    padding: 2rem 1rem;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    border-radius: 1rem;
    color: white;
    box-shadow: var(--card-shadow);
}

.hero-section h1 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-section p {
    font-size: clamp(1rem, 3vw, 1.125rem);
    max-width: 600px;
    margin: 0 auto;
    opacity: 0.9;
    line-height: 1.5;
}

/* Grid Layouts */
.calculator-grid,
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.25rem;
    padding: 1rem 0;
}

/* Card Styles */
.calculator-card,
.tool-card {
    background: white;
    border-radius: 1rem;
    padding: 1.25rem;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    position: relative;
    overflow: hidden;
    text-decoration: none;
    color: var(--text-color);
}

.calculator-card::before,
.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0.25rem;
    background: linear-gradient(to right, var(--primary-color), var(--accent-color));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.calculator-card:hover,
.tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--hover-shadow);
}

.calculator-card:hover::before,
.tool-card:hover::before {
    opacity: 1;
}

/* Tool Category Styles */
.tool-category {
    margin: 2rem 0;
    padding: 0 1rem;
}

.tool-category h2 {
    font-size: clamp(1.5rem, 4vw, 1.75rem);
    color: var(--text-color);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.tool-category h2 i {
    color: var(--primary-color);
}

@media (max-width: 640px) {
    .tool-category {
        margin: 1.5rem 0;
    }
    
    .tool-card {
        padding: 1.25rem;
    }
}

/* Form Elements */
input[type="text"],
input[type="number"],
input[type="email"],
textarea,
select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    background-color: white;
    transition: border-color 0.2s;
    -webkit-appearance: none;
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
}

button {
    cursor: pointer;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--primary-color);
    color: white;
    transition: background-color 0.2s;
}

button:hover {
    background-color: var(--secondary-color);
}


/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #1a1a1a;
        --text-color: #e5e7eb;
        --border-color: #374151;
    }

    body {
        background-color: var(--background-color);
    }

    header,
    .calculator-card,
    .tool-card,
    .dropdown-content {
        background-color: #2d2d2d;
    }

    input[type="text"],
    input[type="number"],
    input[type="email"],
    textarea,
    select {
        background-color: #374151;
        color: var(--text-color);
        border-color: #4b5563;
    }

    .dropdown-content a:hover {
        background-color: #374151;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

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

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }
}

/* Print Styles */
@media print {
    .no-print {
        display: none !important;
    }
}

/* Footer Styles */
footer {
    background-color: white;
    box-shadow: var(--card-shadow);
    padding: 3rem 1rem 1rem;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.footer-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.footer-section p {
    color: var(--text-color);
    opacity: 0.8;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
    padding: 0;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-color);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-section ul li a:hover {
    opacity: 1;
    color: var(--primary-color);
}

.footer-bottom {
    max-width: 1200px;
    margin: 2rem auto 0;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-color);
    opacity: 0.8;
}

/* Number Generator Styles */
.number-generator-container {
    max-width: 600px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: white;
    border-radius: 1rem;
    box-shadow: var(--card-shadow);
}

.generator-form {
    margin: 2rem 0;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.generate-btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.generate-btn:hover {
    background-color: var(--secondary-color);
}

.result-container {
    margin: 2rem 0;
    text-align: center;
}

.number-result {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 1rem 0;
}

.copy-btn {
    padding: 0.5rem 1rem;
    background-color: var(--background-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.copy-btn:hover {
    background-color: white;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.history-container {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.history-container h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

#history-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

#history-list li {
    padding: 0.75rem;
    background-color: var(--background-color);
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    font-family: monospace;
    font-size: 1.1rem;
    text-align: center;
}

/* Responsive adjustments for number generator */
@media (max-width: 768px) {
    .number-generator-container {
        margin: 1rem;
        padding: 1rem;
    }

    .number-result {
        font-size: 2.5rem;
    }
}

/* Mobile and Tablet Responsive Design */
@media (max-width: 768px) {
    nav {
        padding: 0.5rem;
    }

    .nav-links {
        width: 100%;
        justify-content: center;
    }

    .hero-section {
        margin: 0.5rem;
        padding: 1.5rem 1rem;
    }

    .hero-section h1 {
        font-size: 2rem;
    }

    .calculator-grid,
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        padding: 0.5rem;
    }

    .calculator-card {
        margin: 0 1rem;
    }

    .dropdown-content {
        position: fixed;
        top: auto;
        left: 0;
        right: 0;
        width: 100%;
        max-height: 70vh;
        border-radius: 1rem 1rem 0 0;
        padding: 1rem;
        background-color: var(--background-color);
        min-width: 100%;
        margin-top: 0.5rem;
    }

    .dropdown-content::before {
        display: none;
    }

    .dropdown-content a {
        padding: 0.75rem 1rem;
    }

    .dropdown-content a:hover {
        background-color: white;
    }

    input,
    select,
    textarea {
        font-size: 16px; /* Prevents iOS zoom */
    }

    button {
        width: 100%;
        padding: 0.875rem;
    }
}

/* Calculator Page Styles */
.calculator-page {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.calculator-page h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
}


/* Related Tools Section */
.related-tools {
    background: white;
    padding: 3rem 0;
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
}

.related-tools .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.related-tools h2 {
    text-align: center;
    color: var(--text-color);
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 2rem;
    position: relative;
}

.related-tools h2::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 3rem;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.related-tools .tool-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    padding: 1.5rem;
    text-decoration: none;
    color: var(--text-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    box-shadow: var(--card-shadow);
}

.related-tools .tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.related-tools .tool-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--hover-shadow);
    border-color: var(--primary-color);
}

.related-tools .tool-card:hover::before {
    transform: scaleX(1);
}

.related-tools .tool-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    transition: transform 0.3s ease;
}

.related-tools .tool-card:hover i {
    transform: scale(1.1);
}

.related-tools .tool-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.related-tools .tool-card p {
    font-size: 0.875rem;
    color: #64748b;
    line-height: 1.5;
    margin: 0;
}

/* Dark mode support for related tools */
@media (prefers-color-scheme: dark) {
    .related-tools {
        background: #1e293b;
        border-top-color: #334155;
    }
    
    .related-tools .tool-card {
        background: #334155;
        border-color: #475569;
        color: #f1f5f9;
    }
    
    .related-tools .tool-card h3 {
        color: #f1f5f9;
    }
    
    .related-tools .tool-card p {
        color: #94a3b8;
    }
    
    .related-tools .tool-card:hover {
        border-color: var(--primary-color);
        background: #475569;
    }
}

/* Mobile responsiveness for related tools */
@media (max-width: 768px) {
    .related-tools {
        padding: 2rem 0;
        margin-top: 2rem;
    }
    
    .related-tools h2 {
        font-size: 1.5rem;
        margin-bottom: 1.5rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        margin-top: 1.5rem;
    }
    
    .related-tools .tool-card {
        padding: 1.25rem;
    }
    
    .related-tools .tool-card i {
        font-size: 2rem;
        margin-bottom: 0.75rem;
    }
    
    .related-tools .tool-card h3 {
        font-size: 1rem;
    }
    
    .related-tools .tool-card p {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .related-tools .container {
        padding: 0 0.75rem;
    }
    
    .related-tools .tool-card {
        padding: 1rem;
    }
}