:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --background-color: #f8f9fa;
    --text-color: #333;
    --text-light: #666;
    --border-color: #e9ecef;
    --card-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    --card-hover-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    --transition-speed: 0.3s;
    --card-radius: 12px;
    --btn-radius: 8px;
}

html {
    scroll-behavior: smooth;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Navigation */
nav {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color var(--transition-speed) ease;
    font-size: 0.95rem;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--secondary-color);
}

.lang-switcher {
    margin-left: 1rem;
}

.lang-switcher select {
    padding: 6px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: white;
    font-size: 0.9rem;
    cursor: pointer;
    transition: border-color var(--transition-speed) ease;
}

.lang-switcher select:hover {
    border-color: var(--secondary-color);
}

.mobile-menu {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.mobile-menu span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: var(--transition-speed);
}

/* Header Section */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #2980b9 100%);
    color: white;
    text-align: center;
    padding: 6rem 0;
    position: relative;
    overflow: hidden;
    margin-bottom: 2rem;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMjAiIGhlaWdodD0iMjAiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGNpcmNsZSBjeD0iMSIgY3k9IjEiIHI9IjEiIGZpbGw9InJnYmEoMjU1LDI1NSwyNTUsMC4wNSkiLz48L3N2Zz4=');
    mask-image: linear-gradient(to bottom, black, transparent);
}

header h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    font-weight: 800;
    letter-spacing: -1px;
    position: relative;
}

header p {
    font-size: 1.4rem;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0.9;
    font-weight: 300;
    position: relative;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    transition: transform 0.2s ease;
}

.back-link:hover {
    transform: translateX(-5px);
    color: white;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem 0;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        gap: 0;
        z-index: 999;
    }

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

    .nav-links li {
        width: 100%;
        text-align: center;
    }

    .nav-links a {
        display: block;
        padding: 1rem;
    }

    .mobile-menu {
        display: flex;
    }

    .mobile-menu-btn {
        display: block;
    }

    header h1 {
        font-size: 2.5rem;
    }

    header p {
        font-size: 1.1rem;
        padding: 0 1rem;
    }
}

/* Comparison Grid */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
    margin-bottom: 5rem;
}

/* Product Card */
.product-card {
    background: white;
    border-radius: var(--card-radius);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
    height: 100%;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--card-hover-shadow);
    border-color: transparent;
}

.product-header {
    padding: 2.5rem 2rem;
    text-align: center;
    color: white;
    background-color: var(--primary-color); /* Default fallback */
    position: relative;
    overflow: hidden;
}

/* Add subtle texture or gradient overlay to product headers if desired */
.product-header::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(rgba(0,0,0,0), rgba(0,0,0,0.1));
    pointer-events: none;
}

/* Service Colors */
.stripe { background: linear-gradient(135deg, #635bff 0%, #4b45c2 100%); }
.adyen { background: linear-gradient(135deg, #0abf53 0%, #00993e 100%); }
.paddle { background: linear-gradient(135deg, #feb832 0%, #f39c12 100%); color: #333; }
.paypal { background: linear-gradient(135deg, #003087 0%, #009cde 100%); }
.square { background: linear-gradient(135deg, #333333 0%, #000000 100%); }
.resend { background: linear-gradient(135deg, #000000 0%, #333333 100%); }
.mailgun { background: linear-gradient(135deg, #fd5d64 0%, #d83a40 100%); }
.sendgrid { background: linear-gradient(135deg, #1a82e2 0%, #0056b3 100%); }
.amazon-ses { background: linear-gradient(135deg, #232f3e 0%, #ff9900 100%); }
.giffgaff { background: linear-gradient(135deg, #000000 0%, #333333 100%); }
.tello { background: linear-gradient(135deg, #0052cc 0%, #003380 100%); }
.ultra-mobile { background: linear-gradient(135deg, #662d91 0%, #4b216d 100%); }
.ctm { background: linear-gradient(135deg, #009b4c 0%, #007a3b 100%); }
.three-hk { background: linear-gradient(135deg, #e3007b 0%, #b30060 100%); }
.calendly { background: linear-gradient(135deg, #006bff 0%, #0050c0 100%); }
.cal-com { background: linear-gradient(135deg, #111111 0%, #333333 100%); }
.youcanbook { background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%); }
.redis-cloud { background: linear-gradient(135deg, #dc382d 0%, #a31e15 100%); }
.upstash { background: linear-gradient(135deg, #00e9a3 0%, #00b37e 100%); color: #333; }
.aws-elasticache { background: linear-gradient(135deg, #232f3e 0%, #ff9900 100%); }
.cloudflare { background: linear-gradient(135deg, #f38020 0%, #faae40 100%); }
.s3 { background: linear-gradient(135deg, #ff9900 0%, #ffc400 100%); }
.gcs { background: linear-gradient(135deg, #4285f4 0%, #34a853 100%); }

.product-logo {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.product-name {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.product-tagline {
    font-size: 0.9rem;
    opacity: 0.9;
}

.product-content {
    padding: 2rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

/* Feature List */
.feature-list {
    list-style: none;
    margin-bottom: 2rem;
    padding: 0 0.5rem;
}

.feature-list li, .feature-item {
    margin-bottom: 1rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    color: var(--text-color);
    line-height: 1.5;
}

.feature-icon, .feature-item i {
    font-size: 1.2rem;
    width: 24px;
    text-align: center;
    flex-shrink: 0;
    color: var(--secondary-color);
}

/* Pros & Cons */
.pros-cons {
    margin-bottom: 2rem;
    background: #fafbfc;
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.pros-cons h4 {
    margin-bottom: 1rem;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 700;
}

.pros-cons ul {
    list-style: none;
    padding-left: 0;
}

.pros-cons li {
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    color: var(--text-light);
    display: flex;
    gap: 0.5rem;
}

.pros { color: #27ae60; }
.cons { color: #e74c3c; margin-top: 2rem; }

/* Pricing */
.pricing {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    border: 1px dashed var(--border-color);
}

.pricing h4 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 700;
}

.price-item {
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    padding-bottom: 0.5rem;
}

.price-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.price-item.highlight {
    background-color: #e8f5e9;
    color: #2e7d32;
    font-weight: 600;
    border-radius: 4px;
    padding: 0.5rem;
    margin: 0.5rem -0.5rem;
    border-bottom: none;
}

/* CTA Button */
.cta-button {
    display: block;
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 1.2rem;
    border-radius: var(--btn-radius);
    font-weight: 600;
    margin-top: auto;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.95rem;
    box-shadow: 0 4px 6px rgba(44, 62, 80, 0.2);
}

.cta-button:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(52, 152, 219, 0.3);
}

/* Comparison Table */
.comparison-table {
    background: white;
    border-radius: var(--card-radius);
    padding: 2.5rem;
    box-shadow: var(--card-shadow);
    overflow-x: auto;
    margin-bottom: 5rem;
    border: 1px solid var(--border-color);
}

.comparison-table h2 {
    text-align: center;
    margin-bottom: 2.5rem;
    color: var(--primary-color);
    font-size: 2rem;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    min-width: 800px;
}

th, td {
    padding: 1.2rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: #f8f9fa;
    font-weight: 700;
    color: var(--primary-color);
    position: sticky;
    top: 0;
}

th:first-child {
    border-top-left-radius: 8px;
    border-bottom-left-radius: 8px;
}

th:last-child {
    border-top-right-radius: 8px;
    border-bottom-right-radius: 8px;
}

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

tr:hover td {
    background-color: #f1f3f5;
}

td:first-child {
    font-weight: 600;
    color: var(--primary-color);
    background-color: white;
    position: sticky;
    left: 0;
    z-index: 1;
}

/* API Examples */
.api-examples {
    margin-top: 5rem;
}

.api-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2.5rem;
    margin-top: 2.5rem;
}

.api-example {
    background: white;
    border-radius: var(--card-radius);
    padding: 2rem;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
}

.api-example h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.code-block {
    background: #282c34;
    color: #abb2bf;
    padding: 1.5rem;
    border-radius: 8px;
    font-family: 'Fira Code', Consolas, Monaco, monospace;
    font-size: 0.9rem;
    overflow-x: auto;
    white-space: pre;
    line-height: 1.5;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

/* Footer */
footer {
    background-color: white;
    padding: 4rem 0;
    margin-top: 6rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.footer-content h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    font-size: 1.8rem;
}

.footer-guide {
    text-align: left;
    max-width: 800px;
    margin: 20px auto;
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.footer-guide p {
    margin-bottom: 1rem;
    font-size: 1rem;
    line-height: 1.7;
}

.footer-guide p:last-child {
    margin-bottom: 0;
}

.footer-bottom {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Section Titles */
.section-title {
    text-align: center;
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    margin-top: 4rem;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Info Blocks */
.info-block {
    margin-bottom: 1.5rem;
}

.info-block h4 {
    font-size: 1rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-weight: 700;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.info-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.info-item span:first-child {
    font-weight: 500;
    color: var(--text-light);
}

.info-item span:last-child {
    font-weight: 600;
    color: var(--text-color);
    text-align: right;
}

/* Alert Box */
.alert-box {
    background-color: #fff3cd;
    border: 1px solid #ffeeba;
    color: #856404;
    padding: 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    margin-top: auto;
    line-height: 1.5;
}

/* Table Status Colors */
.check { color: #27ae60; font-weight: bold; }
.cross { color: #e74c3c; font-weight: bold; }
.partial { color: #f39c12; font-weight: bold; }

/* Home Page Styles */
.tools-section {
    padding: 2rem 0 5rem;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    margin-bottom: 3rem;
}

.tool-card {
    background: white;
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-speed) ease;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
}

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

.tool-card .icon {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    display: inline-block;
    filter: drop-shadow(0 4px 6px rgba(0,0,0,0.1));
    background: none;
    width: auto;
    height: auto;
    line-height: normal;
    border-radius: 0;
}

.tool-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
    font-weight: 700;
}

.tool-card p {
    color: var(--text-light);
    margin-bottom: 2rem;
    line-height: 1.6;
    flex-grow: 1;
}

.tool-card .btn {
    display: inline-block;
    background-color: var(--secondary-color);
    color: white;
    padding: 0.8rem 2rem;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
    box-shadow: 0 4px 6px rgba(52, 152, 219, 0.2);
}

.tool-card .btn:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(52, 152, 219, 0.3);
}

/* Performance Chart */
.performance-chart {
    margin-bottom: 5rem;
    background: white;
    padding: 2rem;
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
}

.chart-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.chart-item {
    text-align: center;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.chart-item h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
}

.metric {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.metric:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.metric-value {
    font-weight: 700;
    color: var(--secondary-color);
}

/* Use Cases */
.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.case-item {
    background: white;
    padding: 2rem;
    border-radius: var(--card-radius);
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
}

.case-item h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
    display: inline-block;
}

.case-item ul {
    list-style: none;
}

.case-item li {
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-color);
}

.case-item li::before {
    content: "•";
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Standard Site Footer (added for index.html) */
.site-footer {
    background-color: var(--primary-color);
    color: white;
    padding: 4rem 0 2rem;
    margin-top: 0; /* Override default margin if needed */
    border-top: none;
}

.footer-links-grid {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    text-align: left;
}

.footer-section h4 {
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    font-weight: 700;
    color: white;
}

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

.footer-section ul li {
    margin-bottom: 0.8rem;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}

.footer-section ul li a:hover {
    color: white;
    padding-left: 5px;
}

/* Footer Bottom (shared/overridden) */
.site-footer .footer-bottom {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}