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

:root {
    --primary-color: #0ea5e9;
    --primary-dark: #0284c7;
    --secondary-color: #38bdf8;
    --text-color: #0f172a;
    --text-secondary: #64748b;
    --background: #ffffff;
    --background-secondary: #f8fafc;
    --border-color: #e2e8f0;
    --success-color: #22c55e;
    --shadow: 0 6px 18px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 36px rgba(15, 23, 42, 0.12);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background:
        radial-gradient(circle at 12% 8%, oklch(88% 0.13 186 / 0.28), transparent 30rem),
        linear-gradient(180deg, oklch(98% 0.008 210), var(--background));
}

/* Header and Navigation */
header {
    background: var(--background);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
    background: rgba(255, 255, 255, 0.8);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 18px;
    min-width: 0;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 700;
    font-size: 0.95rem;
    white-space: nowrap;
}

.brand img {
    width: 34px;
    height: 34px;
    border-radius: 10px;
    background: #ffffff;
    padding: 6px;
    box-shadow: var(--shadow);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
    text-decoration: none;
}

.logo img {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: #ffffff;
    padding: 6px;
    box-shadow: var(--shadow);
}

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

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

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

/* Hero Section */
.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: clamp(4rem, 8vw, 8rem) 2rem 5rem;
    display: grid;
    grid-template-columns: minmax(0, 0.88fr) minmax(320px, 1.12fr);
    gap: clamp(2rem, 6vw, 5rem);
    align-items: center;
}

.hero-content h1 {
    max-width: 10ch;
    font-size: clamp(3.2rem, 7vw, 6.6rem);
    font-weight: 700;
    line-height: 0.92;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    letter-spacing: 0;
}

.eyebrow {
    display: inline-flex;
    margin: 0 0 1rem;
    padding: 0.42rem 0.72rem;
    border-radius: 999px;
    background: oklch(93% 0.09 194);
    color: oklch(31% 0.1 206);
    font-weight: 800;
    font-size: 0.86rem;
}

.tagline {
    max-width: 36rem;
    font-size: clamp(1.18rem, 1.1rem + 0.8vw, 1.58rem);
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.38;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
}

.reader-scene {
    position: relative;
    display: grid;
    gap: 14px;
    padding: clamp(20px, 4vw, 42px);
    border-radius: 18px;
    background: linear-gradient(135deg, oklch(20% 0.04 235), oklch(32% 0.09 210));
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.reader-scene::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 90% 8%, oklch(77% 0.14 190 / 0.34), transparent 18rem);
}

.reader-scene img,
.reader-scene article {
    position: relative;
    z-index: 1;
}

.reader-scene img {
    width: 82px;
    height: 82px;
    border-radius: 18px;
    background: oklch(98% 0.012 210);
    padding: 8px;
    box-shadow: 0 16px 34px rgba(2, 6, 23, 0.28);
}

.reader-scene article {
    padding: 16px;
    border-radius: 12px;
    background: oklch(99% 0.012 210 / 0.94);
    color: var(--text-color);
}

.reader-scene span {
    color: var(--primary-dark);
    font-weight: 800;
    font-size: 0.82rem;
}

.reader-scene strong,
.reader-scene small {
    display: block;
}

.reader-scene small {
    margin-top: 5px;
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

.btn-large {
    padding: 1.125rem 3rem;
    font-size: 1.125rem;
}

/* Features Section */
.features {
    background:
        linear-gradient(180deg, var(--background-secondary), oklch(95% 0.02 210));
    padding: 6rem 2rem;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 4rem;
    color: var(--text-color);
}

.features-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--background);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: transform 0.2s;
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 56px;
    height: 56px;
    margin-bottom: 1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 14px;
    background: var(--background-secondary);
    border: 1px solid var(--border-color);
    color: var(--primary-dark);
}

.feature-icon svg {
    width: 28px;
    height: 28px;
}

@media (max-width: 768px) {
    .brand span {
        display: none;
    }
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* How It Works Section */
.how-it-works {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem 6rem;
}

.how-it-works h2 {
    max-width: 760px;
    text-align: left;
    font-size: clamp(2.2rem, 4vw, 4rem);
    line-height: 1;
    margin-bottom: 3rem;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
}

.step {
    text-align: left;
    padding: 24px;
    border-radius: 14px;
    background: oklch(99% 0.01 210);
    border: 1px solid var(--border-color);
}

.step-number {
    width: 60px;
    height: 60px;
    background: oklch(91% 0.11 194);
    color: var(--text-color);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 0 1.5rem;
}

.step h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.step p {
    color: var(--text-secondary);
}

/* Download Section */
.download {
    background: var(--background-secondary);
    text-align: center;
    padding: 6rem 2rem;
}

.download h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.download p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.requirements {
    margin-top: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Content Page Styles */
.content-page {
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.content-page h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.last-updated {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 3rem;
}

.content-page section {
    margin-bottom: 3rem;
}

.content-page h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    margin-top: 2rem;
    color: var(--text-color);
}

.content-page h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
    color: var(--text-color);
}

.content-page p {
    margin-bottom: 1rem;
    line-height: 1.7;
}

.content-page ul,
.content-page ol {
    margin-bottom: 1rem;
    padding-left: 2rem;
}

.content-page li {
    margin-bottom: 0.5rem;
    line-height: 1.7;
}

.content-page a {
    color: var(--primary-color);
    text-decoration: none;
}

.content-page a:hover {
    text-decoration: underline;
}

.highlight-box {
    background: var(--background-secondary);
    border-left: 4px solid var(--primary-color);
    padding: 1.5rem;
    border-radius: 8px;
    margin: 2rem 0;
}

.highlight-box h3 {
    margin-top: 0;
}

.nsg-mark {
    width: min(100%, 340px);
    height: auto;
    margin: 0.25rem 0 1rem;
}

.nsg-mark-footer {
    width: min(100%, 260px);
}

.faq-item {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

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

/* Footer */
footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 2rem 1rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

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

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

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    max-width: 1200px;
    margin: 0 auto;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-content h1 {
        font-size: 2.5rem;
    }
    
    .tagline {
        font-size: 1.25rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        gap: 1rem;
    }
    
    .hero-image {
        order: -1;
    }
    
    .hero-image img {
        max-width: 250px;
        margin: 0 auto;
    }
    
    .nav-links {
        gap: 1rem;
        font-size: 0.875rem;
    }
    
    .nav-container {
        padding: 1rem;
    }
    
    .features h2,
    .how-it-works h2,
    .download h2 {
        font-size: 2rem;
    }
    
    .content-page {
        padding: 2rem 1rem;
    }
    
    .content-page h1 {
        font-size: 2rem;
    }
}