/* Import modern font from Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;600;700&display=swap');

:root {
    /* Light Mode Palette */
    --primary: #6366f1; /* Indigo 500 */
    --primary-hover: #4f46e5; /* Indigo 600 */
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --accent: #eff6ff;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    /* Dark Mode Palette */
    --bg-main: #0f172a;
    --bg-card: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border: #334155;
    --accent: #1e293b;
    --shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    transition: var(--transition);
}

h1, h2, h3, .logo {
    font-family: 'Outfit', sans-serif;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Navbar Styles */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(8px);
    transition: var(--transition);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

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

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 500;
    transition: var(--transition);
}

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

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

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    font-size: 1.25rem;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--accent);
}

/* Tool Section */
.hero-section {
    padding: 4rem 0;
    text-align: center;
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.converter-container {
    max-width: 600px;
    margin: 2rem auto;
    padding: 2.5rem;
    background-color: var(--bg-card);
    border-radius: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.input-group {
    margin-bottom: 1.5rem;
    text-align: left;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.input-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1.5px solid var(--border);
    border-radius: 0.75rem;
    background-color: var(--bg-main);
    color: var(--text-main);
    font-size: 1rem;
    transition: var(--transition);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.result-card {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: var(--accent);
    border-radius: 1rem;
    text-align: center;
}

.result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin: 0.5rem 0;
}

.formula {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 1rem;
}

.btn-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1.5rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

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

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

.btn-outline {
    background-color: transparent;
    border: 1.5px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: var(--accent);
}

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

.content-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
}

.content-section p, .content-section ul {
    margin-bottom: 1.5rem;
    color: var(--text-muted);
}

.faq-item {
    margin-bottom: 2rem;
}

.faq-item h3 {
    margin-bottom: 0.5rem;
}

/* Footer */
.footer {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 4rem 0 2rem;
    margin-top: 4rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-logo {
    margin-bottom: 1.5rem;
}

.footer-heading {
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    text-decoration: none;
    color: var(--text-muted);
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Mobile Menu */
.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-main);
    cursor: pointer;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        flex-direction: column;
        background-color: var(--bg-card);
        padding: 2rem;
        border-bottom: 1px solid var(--border);
        text-align: center;
    }

    .nav-links.active {
        display: flex;
    }

    .hamburger {
        display: block;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

/* Loading Animation */
.loader-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-main);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.loader {
    width: 48px;
    height: 48px;
    border: 5px solid var(--border);
    border-bottom-color: var(--primary);
    border-radius: 50%;
    display: inline-block;
    box-sizing: border-box;
    animation: rotation 1s linear infinite;
}

@keyframes rotation {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Smooth fade in */
.fade-in {
    animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}