:root {
    --bg-ink: #00011F;
    --bg-deep: #0A0930;
    --indigo: #052564;
    --neon-blue: #28A8D6;
    --sky-cyan: #5DE3FF;
    --ember-orange: #FF7A1A;
    --gold: #D4B770;
    --text: #E7F3FD;
    --max-width: 1100px
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Inter, Arial, sans-serif;
    background: radial-gradient(ellipse at center, var(--bg-deep) 0%, var(--bg-ink) 70%), linear-gradient(135deg, var(--bg-ink) 0%, var(--indigo) 100%);
    background-attachment: fixed;
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh
}

body:before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(circle at 25% 25%, rgba(94, 227, 255, .1) 1px, transparent 1px), radial-gradient(circle at 75% 75%, rgba(40, 168, 214, .08) 1px, transparent 1px);
    background-size: 100px 100px, 150px 150px;
    pointer-events: none;
    z-index: -1
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem
}

.footer-copyright {
    text-align: center;
    margin-bottom: 12px;
}

@media (min-width: 640px) {
    .container {
        padding: 0 1.5rem
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 2rem
    }
}

h1 {
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--sky-cyan), var(--neon-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text
}

h2 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--sky-cyan)
}

.subhead {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    font-weight: 300;
    color: var(--gold);
    margin-bottom: 1rem
}

.badge {
    display: inline-block;
    background: #28a8d633;
    border: 1px solid var(--neon-blue);
    padding: .5rem 1rem;
    border-radius: 2rem;
    font-size: .875rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    color: var(--sky-cyan)
}

.description {
    font-size: clamp(1rem, 2.5vw, 1.125rem);
    line-height: 1.7;
    margin-bottom: 2rem;
    max-width: 600px
}

.hero {
    padding: 2rem 0 3rem;
    min-height: 100vh;
    display: flex;
    align-items: center
}

@media (min-width: 640px) {
    .hero {
        padding: 3rem 0 4rem
    }
}

@media (min-width: 1024px) {
    .hero {
        padding: 4rem 0 6rem
    }
}

.hero-content {
    display: grid;
    gap: 2rem;
    align-items: center;
    text-align: center
}

@media (min-width: 640px) {
    .hero-content {
        gap: 2.5rem
    }
}

@media (min-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr 1.2fr;
        gap: 4rem;
        text-align: left
    }
}

.book-cover {
    justify-self: center
}

@media (min-width: 768px) {
    .book-cover {
        justify-self: end
    }
}

.cover-image {
    width: 100%;
    max-width: 280px;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 20px 40px #0000004d, 0 0 30px #28a8d633;
    transition: all .3s ease
}

@media (max-width: 639px) {
    .cover-image {
        max-width: 320px;
        min-width: 280px;
        width: 90vw
    }
}

.cover-image:hover,
.cover-image:focus {
    transform: translateY(-8px) scale(1.03) rotate(1.5deg);
    box-shadow: 0 30px 60px #0006, 0 0 50px #28a8d666
}

.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, var(--neon-blue), var(--sky-cyan));
    color: var(--bg-ink);
    padding: .875rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all .3s ease;
    position: relative;
    overflow: hidden;
    text-align: center;
    max-width: 100%
}

@media (min-width: 640px) {
    .cta-button {
        padding: 1rem 2rem;
        font-size: 1.125rem
    }
}

.cta-button:hover,
.cta-button:focus {
    background: linear-gradient(135deg, var(--sky-cyan), var(--ember-orange));
    transform: translateY(-2px);
    box-shadow: 0 10px 30px #28a8d666
}

.cta-button:focus {
    outline: 2px solid var(--sky-cyan);
    outline-offset: 4px
}

.about,
.learn,
.social-proof {
    padding: 2rem 0;
    border-top: 1px solid rgba(40, 168, 214, .2)
}

@media (min-width: 640px) {
    .about,
    .learn,
    .social-proof {
        padding: 3rem 0
    }
}

@media (min-width: 1024px) {
    .about,
    .learn,
    .social-proof {
        padding: 4rem 0
    }
    
    .no-wrap {
        white-space: nowrap
    }
}

.learn ul {
    list-style: none;
    max-width: 700px
}

.learn li {
    border-left: 3px solid var(--neon-blue);
    padding: 1rem 0 1rem 1.5rem;
    margin-bottom: 1rem;
    font-size: 1.125rem
}

.social-proof {
    text-align: center;
    font-style: italic;
    font-size: 1.25rem;
    color: var(--gold)
}

.common-sense {
    padding: 2rem 0;
    background: var(--bg-deep)
}

@media (min-width: 640px) {
    .common-sense {
        padding: 3rem 0
    }
}

@media (min-width: 1024px) {
    .common-sense {
        padding: 4rem 0
    }
}

.common-sense h2 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    margin-bottom: 1.5rem;
    color: var(--neon-blue);
    text-align: center
}

@media (min-width: 640px) {
    .common-sense h2 {
        margin-bottom: 2rem
    }
}

.common-sense p {
    font-size: clamp(1rem, 2.5vw, 1.125rem);
    line-height: 1.7;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: 0 1rem
}

@media (min-width: 640px) {
    .common-sense p {
        padding: 0
    }
}

.social-proof {
    padding: 3rem 0;
    text-align: center
}

@media (min-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr 1.2fr;
        gap: 4rem
    }

    .book-cover {
        justify-self: end
    }

    .cover-image {
        max-width: 350px
    }
}

@media (prefers-reduced-motion: reduce) {
    .cover-image:hover,
    .cover-image:focus {
        transform: none;
        filter: brightness(1.1)
    }

    .cta-button:hover,
    .cta-button:focus {
        transform: none
    }

    * {
        transition: none !important
    }
}