:root {
    --bg-dark: #171c22;
    --bg-mid: #212a33;
    --surface: #f2f5f7;
    --surface-deep: #dde5ea;
    --text-dark: #1f2a34;
    --text-soft: #5f6d78;
    --white: #ffffff;
    --accent: #2b7a78;
    --accent-2: #3273dc;
    --border: rgba(31, 42, 52, 0.12);
    --shadow: 0 1rem 2rem rgba(10, 20, 30, 0.14);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Source Sans 3', Arial, sans-serif;
    color: var(--text-dark);
    background: #ffffff;
    line-height: 1.65;
}

.site-navbar {
    background: linear-gradient(90deg, #1b232c, #26333f);
}

.brand-logo {
    width: 42px;
    height: 42px;
    object-fit: contain;
}

.brand-text {
    font-size: 1.2rem;
    font-weight: 800;
    letter-spacing: 0.04em;
}

.navbar-dark .navbar-nav .nav-link {
    color: rgba(255,255,255,0.88);
    font-weight: 600;
    letter-spacing: 0.01em;
}

.navbar-dark .navbar-nav .active > .nav-link,
.navbar-dark .navbar-nav .nav-link:hover {
    color: #9ce5d5;
}

.hero-section {
    background:
        linear-gradient(135deg, rgba(23,28,34,0.95), rgba(40,54,66,0.93)),
        radial-gradient(circle at top right, rgba(50,115,220,0.18), transparent 35%);
    color: var(--white);
    padding: 5.5rem 0;
}

.hero-logo {
    max-width: 380px;
    filter: drop-shadow(0 18px 45px rgba(0,0,0,0.45));
}

.eyebrow {
    display: inline-block;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    font-size: 0.82rem;
    font-weight: 700;
    color: #8dd8d6;
}

.text-soft,
.section-text {
    color: var(--text-soft);
}

.section-pad {
    padding: 4.5rem 0;
}

.section-surface,
.page-banner {
    background: var(--surface);
}

.page-banner {
    padding: 4rem 0 2.5rem;
    border-bottom: 1px solid var(--border);
}

.section-title,
.page-banner h1,
.cta-panel h2 {
    font-weight: 800;
    line-height: 1.2;
}

.feature-card,
.info-card,
.form-card,
.book-panel {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 50%;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    color: var(--white);
    font-weight: 800;
    font-size: 0.95rem;
}

.featured-book-cover {
    max-width: 300px;
    border-radius: 1rem;
}

.badge-accent {
    background: rgba(43, 122, 120, 0.12);
    color: var(--accent);
    font-weight: 700;
    border: 1px solid rgba(43, 122, 120, 0.18);
    padding: 0.55rem 0.85rem;
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    border: none;
    color: var(--white);
    font-weight: 700;
    box-shadow: 0 0.65rem 1.25rem rgba(43, 122, 120, 0.24);
}

.btn-accent:hover,
.btn-accent:focus {
    color: var(--white);
    opacity: 0.95;
}

.btn-outline-light,
.btn-outline-secondary {
    font-weight: 700;
}

.cta-panel-wrap {
    background: linear-gradient(180deg, #ffffff 0%, #eff4f7 100%);
}

.cta-panel {
    background: linear-gradient(135deg, #24303b, #2e4050);
    color: var(--white);
    border-radius: 1.2rem;
    padding: 2.2rem;
    box-shadow: var(--shadow);
}

.format-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0.85rem;
    text-align: center;
    padding: 1rem;
    font-weight: 700;
    color: var(--text-dark);
}

.info-list li {
    padding: 0.45rem 0;
    border-bottom: 1px solid var(--border);
}

.info-list li:last-child {
    border-bottom: 0;
}

.form-control {
    border-radius: 0.7rem;
    border: 1px solid rgba(31, 42, 52, 0.16);
    padding: 0.85rem 1rem;
}

.form-control:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 0.2rem rgba(43, 122, 120, 0.18);
}

.narrow-content h2 {
    margin-top: 2rem;
    font-size: 1.4rem;
    font-weight: 800;
}

.site-footer {
    background: #182028;
    color: var(--white);
    padding: 2.5rem 0;
}

.footer-link {
    color: #b9d8ea;
}

.footer-link:hover {
    color: #ffffff;
    text-decoration: none;
}

.footer-sep {
    margin: 0 0.45rem;
    color: rgba(255,255,255,0.35);
}

.footer-rule {
    border-color: rgba(255,255,255,0.08);
    margin: 1.5rem 0;
}

.text-muted-light {
    color: rgba(255,255,255,0.72);
}

code {
    color: #1c5a8b;
}

@media (max-width: 991.98px) {
    .hero-section {
        padding: 4rem 0;
    }

    .display-4 {
        font-size: 2.6rem;
    }
}

@media (max-width: 575.98px) {
    .section-pad {
        padding: 3.5rem 0;
    }

    .feature-card,
    .info-card,
    .form-card,
    .book-panel {
        padding: 1.4rem;
    }

    .hero-logo {
        max-width: 250px;
    }
}