@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');

:root {
    --primary-color: #ef4444;
    /* Red color as requested in recent context */
    --primary-hover: #dc2626;
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.95);
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --success-color: #ef4444;
    --success-bg: #fef2f2;
    --success-border: #fecaca;
    --focus-ring: rgba(239, 68, 68, 0.2);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 20px;
    --gradient: linear-gradient(135deg, #ef4444 0%, #b91c1c 100%);
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    background-image:
        radial-gradient(at 0% 0%, rgba(239, 68, 68, 0.05) 0px, transparent 50%),
        radial-gradient(at 100% 0%, rgba(185, 28, 28, 0.05) 0px, transparent 50%);
    color: var(--text-main);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 800px;
}

.top-nav {
    display: flex;
    justify-content: flex-start;
    margin-bottom: 30px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.converter-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow-lg);
    border: 1px solid white;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    gap: 24px;
    max-width: 500px;
    margin: 0 auto 30px auto;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-group label {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.input-group input {
    width: 100%;
    padding: 16px 20px;
    font-size: 1.75rem;
    border: 2px solid var(--border-color);
    border-radius: 14px;
    font-family: inherit;
    transition: all 0.2s ease;
    background: white;
    color: var(--text-main);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px var(--focus-ring);
}

.result-group label {
    color: var(--primary-color);
}

.result-group input {
    background: var(--success-bg);
    border-color: var(--success-border);
    color: #991b1b;
    font-weight: 700;
}

.arrow-divider {
    display: flex;
    justify-content: center;
    color: var(--text-muted);
    opacity: 0.3;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: 10px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
    font-size: 0.95rem;
}

.btn-outline {
    border: 1px solid var(--border-color);
    color: var(--text-main);
    background: white;
}

.btn-outline:hover {
    background: var(--bg-color);
    border-color: var(--text-muted);
}

.ads-wrapper {
    margin: 20px auto 40px auto;
    width: 100%;
    max-width: 728px;
    min-height: 90px;
    background: white;
    border-radius: 12px;
    padding: 15px;
    box-shadow: var(--shadow-sm);
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Info Section / SEO Article Styles */
.info-section {
    background: white;
    border-radius: var(--radius);
    padding: 48px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 60px;
    text-align: left;
    border: 1px solid var(--border-color);
}

.info-section h2 {
    font-size: 1.85rem;
    margin-bottom: 24px;
    margin-top: 40px;
    color: var(--text-main);
    border-left: 5px solid var(--primary-color);
    padding-left: 20px;
    line-height: 1.2;
}

.info-section h2:first-of-type {
    margin-top: 0;
}

.info-section h3 {
    font-size: 1.35rem;
    margin: 32px 0 16px 0;
    color: var(--text-main);
    font-weight: 600;
}

.info-section p {
    margin-bottom: 20px;
    color: #4b5563;
    line-height: 1.8;
}

.info-section ul,
.info-section ol {
    margin-bottom: 24px;
    padding-left: 24px;
}

.info-section li {
    margin-bottom: 12px;
    color: #4b5563;
}

.table-responsive {
    overflow-x: auto;
    margin: 32px 0;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.info-section table {
    width: 100%;
    border-collapse: collapse;
    min-width: 500px;
}

.info-section th,
.info-section td {
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
    text-align: left;
}

.info-section th {
    background: #f8fafc;
    font-weight: 600;
    color: var(--text-main);
}

.info-section tr:last-child td {
    border-bottom: none;
}

.info-section tr:nth-child(even) {
    background: #fbfcfe;
}

.related-links {
    list-style: none;
    padding-left: 0 !important;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
    margin-top: 24px;
}

.related-links a {
    display: block;
    padding: 12px 16px;
    background: #f8fafc;
    border-radius: 10px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
    border: 1px solid var(--border-color);
    text-align: center;
}

.related-links a:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.faq-item {
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-item h3 {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 1.15rem;
}

.faq-item p {
    margin-bottom: 0;
}

.footer {
    margin-top: auto;
    padding: 40px 0;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
    width: 100%;
}

@media (max-width: 640px) {
    header h1 {
        font-size: 2rem;
    }

    .converter-card {
        padding: 24px;
    }
}
/* Flash Cards Section */
.tools-section {
    width: 100%;
    margin-top: 40px;
    margin-bottom: 60px;
}

.tools-section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 24px;
    text-align: center;
    color: var(--text-main);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
    width: 100%;
}

.tool-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    text-decoration: none;
    color: var(--text-main);
    border: 1px solid var(--border-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

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

.tool-card-title {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 8px;
    color: var(--text-main);
}

.tool-card-desc {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    line-height: 1.4;
}

.tool-card-action {
    display: flex;
    align-items: center;
    gap: 4px;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: auto;
}

.tool-card-action svg {
    transition: transform 0.3s ease;
}

.tool-card:hover .tool-card-action svg {
    transform: translateX(4px);
}