:root {
    --bg-color: #0f172a;
    --bg-color-alt: #131c31;
    --card-bg: #1e293b;
    --card-border: #334155;
    --accent-color: #fbbf24;
    --accent-color-dark: #b45309;
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    --success: #34d399;
    --danger: #f87171;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    line-height: 1.6;
}

a {
    color: inherit;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

.container-narrow {
    max-width: 720px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Buttons */
.btn {
    display: inline-block;
    background-color: var(--accent-color);
    color: #000;
    padding: 18px 35px;
    font-size: 1.1rem;
    font-weight: bold;
    text-decoration: none;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: transform 0.15s ease;
}

.btn:hover {
    transform: scale(1.03);
}

.btn-secondary {
    background: transparent;
    color: var(--text-main);
    border: 1px solid var(--card-border);
}

.btn-block {
    display: block;
    width: 100%;
    text-align: center;
}

.btn-pill {
    background: #fff;
    color: #1e293b;
    border-radius: 999px;
    padding: 16px 28px;
    font-weight: 800;
    text-align: center;
    text-decoration: none;
    display: block;
}

/* Header / Hero */
header.hero {
    padding: 90px 0 50px;
    text-align: center;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 40px;
    align-items: center;
    text-align: left;
}

.hero-visual {
    display: flex;
    justify-content: center;
}

.hero-visual svg {
    width: 100%;
    max-width: 460px;
    height: auto;
}

.eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent-color);
    font-weight: 700;
    font-size: 0.85rem;
    margin-bottom: 18px;
}

h1 {
    font-size: 3.2rem;
    font-weight: 900;
    margin: 0 0 20px;
    line-height: 1.15;
    text-wrap: balance;
}

.highlight {
    color: var(--accent-color);
}

.subheadline {
    font-size: 1.2rem;
    color: var(--text-dim);
    max-width: 780px;
    margin: 0 0 36px;
}

.social-proof {
    margin-top: 18px;
    color: var(--text-dim);
    font-size: 0.9rem;
}

/* Book mockup cards */
.mockup-container {
    margin: 55px 0 30px;
    display: flex;
    justify-content: center;
    gap: 22px;
    flex-wrap: wrap;
}

.book-card {
    background: linear-gradient(160deg, var(--card-bg), var(--bg-color-alt));
    padding: 28px;
    border-radius: 14px;
    border: 1px solid var(--card-border);
    width: 280px;
    text-align: left;
    position: relative;
    overflow: hidden;
}

.book-card::before {
    content: "";
    position: absolute;
    top: -40px;
    right: -40px;
    width: 120px;
    height: 120px;
    background: radial-gradient(circle, rgba(251, 191, 36, 0.18), transparent 70%);
}

.book-number {
    color: var(--accent-color);
    font-weight: 800;
    font-size: 0.85rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.book-card h3 {
    margin: 10px 0 10px;
    font-size: 1.2rem;
}

.book-card p {
    color: var(--text-dim);
    font-size: 0.95rem;
    margin: 0;
}

/* Sections */
section {
    padding: 70px 0;
}

section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 10px;
    text-wrap: balance;
}

.section-lead {
    text-align: center;
    color: var(--text-dim);
    max-width: 640px;
    margin: 0 auto 40px;
}

.problem-section {
    background: var(--card-bg);
    border-radius: 24px;
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 20px;
}

.problem-item {
    padding: 6px 0 6px 20px;
    border-left: 4px solid var(--accent-color);
}

.problem-item strong {
    display: block;
    margin-bottom: 6px;
    font-size: 1.05rem;
}

.problem-item p {
    color: var(--text-dim);
    margin: 0;
}

/* Solution / books */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.book-detail {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 30px;
}

.book-detail .book-number {
    display: inline-block;
    margin-bottom: 12px;
}

.book-detail h3 {
    margin: 0 0 12px;
    font-size: 1.3rem;
}

.book-detail p {
    color: var(--text-dim);
    margin: 0;
}

/* About */
.about-section {
    display: flex;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
    justify-content: center;
}

.about-avatar {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--accent-color);
    flex-shrink: 0;
}

.about-text {
    max-width: 560px;
}

.about-text h2 {
    text-align: left;
    margin-bottom: 14px;
}

.about-text p {
    color: var(--text-dim);
}

.about-text .author-name {
    color: var(--text-main);
    font-weight: 700;
}

/* Upsell preview */
.upsell-section {
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.08), transparent);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    text-align: center;
}

.upsell-section p {
    max-width: 640px;
    margin: 0 auto;
    color: var(--text-dim);
    font-size: 1.05rem;
}

/* Opt-in form */
.optin-form {
    max-width: 420px;
    margin: 30px auto 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.optin-form input[type="text"],
.optin-form input[type="email"] {
    padding: 14px 16px;
    border-radius: 8px;
    border: 1px solid var(--card-border);
    background: var(--card-bg);
    color: var(--text-main);
    font-size: 1rem;
}

.optin-form input::placeholder {
    color: var(--text-dim);
}

.form-message {
    max-width: 420px;
    margin: 16px auto 0;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
}

.form-message.error {
    background: rgba(248, 113, 113, 0.12);
    border: 1px solid var(--danger);
    color: var(--danger);
}

.trust-note {
    margin-top: 14px;
    color: var(--text-dim);
    font-size: 0.8rem;
}

/* Footer */
footer {
    padding: 50px 0 40px;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.9rem;
    border-top: 1px solid var(--card-border);
    margin-top: 30px;
}

footer a {
    color: var(--text-dim);
    text-decoration: underline;
}

footer .footer-links {
    margin-top: 10px;
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.1rem;
    }

    .subheadline {
        font-size: 1.05rem;
    }

    header.hero {
        padding: 60px 0 30px;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-visual {
        order: -1;
        margin-bottom: 10px;
    }

    .hero-visual svg {
        max-width: 280px;
    }

    .subheadline {
        margin-left: auto;
        margin-right: auto;
    }

    section {
        padding: 50px 0;
    }

    .about-section {
        flex-direction: column;
        text-align: center;
    }

    .about-text h2 {
        text-align: center;
    }
}