/* Global Variables */
:root {
    --primary-color: #10b981;
    --primary-dark: #0da271;
    --bg-color: #ffffff;
    --text-color: #333333;
    --card-bg: #ffffff;
    --border-color: #dee2e6;
    --shadow-color: rgba(0,0,0,0.1);
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
}

[data-theme="dark"] {
    --primary-color: #34d399;
    --primary-dark: #10b981;
    --bg-color: #1a1a1a;
    --text-color: #f0f0f0;
    --card-bg: #2d2d2d;
    --border-color: #444444;
    --shadow-color: rgba(0,0,0,0.3);
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Varela Round', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
    line-height: 1.6;
}

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

/* Header Styles - EXACT SAME AS CM TO INCHES */
header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
    align-items: center;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 6px;
    transition: all 0.3s;
}

nav a:hover {
    background: var(--primary-color);
    color: white;
}

.dropdown {
    position: relative;
}

.dropdown summary {
    list-style: none;
    cursor: pointer;
    padding: 8px 16px;
    border-radius: 6px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}

.dropdown summary::-webkit-details-marker {
    display: none;
}

.dropdown ul {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 4px 12px var(--shadow-color);
    padding: 10px 0;
    display: none;
    flex-direction: column;
}

.dropdown[open] ul {
    display: flex;
}

.dropdown ul li {
    width: 100%;
}

.dropdown ul a {
    display: block;
    padding: 12px 20px;
    border-radius: 0;
}

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

.logo img {
    height: 32px;
    width: 32px;
    filter: invert(var(--img-invert, 0));
}

.theme-switch {
    cursor: pointer;
    padding: 8px 16px;
    border-radius: 20px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: 'Varela Round', sans-serif;
    font-size: 0.9rem;
}

.theme-switch:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Main Content */
main {
    padding: 40px 0;
    min-height: calc(100vh - 200px);
}

/* Calculator Container */
.calculator-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--card-bg);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 4px 20px var(--shadow-color);
    border: 1px solid var(--border-color);
}

.calculator-title {
    text-align: center;
    margin-bottom: 30px;
    color: var(--text-color);
}

.calculator-title h1 {
    font-size: 2rem;
    margin-bottom: 10px;
}

.calculator-title p {
    opacity: 0.8;
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    color: var(--text-color);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--card-bg);
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.range-container {
    display: flex;
    align-items: center;
    gap: 15px;
}

.range-container input[type="range"] {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.range-container input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: 2px solid var(--card-bg);
}

.range-value {
    min-width: 60px;
    font-weight: bold;
    color: var(--primary-color);
}

/* Results Section */
.results-section {
    margin-top: 30px;
    padding: 20px;
    background: var(--card-bg);
    border-radius: 10px;
    border: 1px solid var(--border-color);
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin: 20px 0;
}

.result-card {
    padding: 15px;
    background: var(--bg-color);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    text-align: center;
}

.result-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    margin: 10px 0;
}

.result-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: all 0.3s;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-block {
    display: block;
    width: 100%;
}

.btn-secondary {
    background: var(--border-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background: var(--text-color);
    color: var(--card-bg);
}

/* Tool Grid */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.tool-card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 20px;
    text-decoration: none;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.tool-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 8px 20px var(--shadow-color);
}

.tool-icon {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

/* Footer */
footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 40px 0 20px;
    margin-top: 60px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-links h4 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.footer-links a {
    display: block;
    color: var(--text-color);
    opacity: 0.8;
    text-decoration: none;
    margin: 8px 0;
    transition: all 0.3s;
}

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

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-color);
    opacity: 0.6;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    nav {
        flex-direction: rows;
        gap: 15px;
        padding: 10px 0;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .calculator-container {
        padding: 20px;
    }
    
    .tool-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
    
    .result-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.mb-1 { margin-bottom: 10px; }
.mb-2 { margin-bottom: 20px; }
.mb-3 { margin-bottom: 30px; }
.mt-1 { margin-top: 10px; }
.mt-2 { margin-top: 20px; }
.mt-3 { margin-top: 30px; }
.p-1 { padding: 10px; }
.p-2 { padding: 20px; }
.p-3 { padding: 30px; }

.hidden { display: none; }




/* Simple dropdown fix - stickiness hatane ke liye */
.dropdown summary {
    cursor: pointer;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.dropdown summary::-webkit-details-marker {
    display: none;
}

/* Dropdown open hone par summary ka style change */
.dropdown[open] summary {
    background: var(--primary-color);
    color: white;
}

/* Dropdown list position fix */
.dropdown ul {
    position: absolute;
    top: calc(100% + 5px);
    left: 0;
    z-index: 1000;
    animation: dropdownFade 0.2s ease;
}

@keyframes dropdownFade {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Dropdown ke bahar click karne par close hone ke liye */
.dropdown summary:after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: transparent;
    z-index: 999;
    display: none;
}

.dropdown[open] summary:after {
    display: block;
}