/* =========================================================
   SI — SUPER INTELLIGENCE
   mykindlebooks.net/si-super-intelligence/
   Shared stylesheet
   ========================================================= */

/* ---------- RESET ---------- */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.65;
    color: #172033;
    background: #f5f7fb;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: #1769aa;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}


/* ---------- SITE HEADER ---------- */

.site-header {
    background: linear-gradient(135deg, #07162c, #102d55);
    color: #ffffff;
    padding: 18px 20px;
    border-bottom: 3px solid #39bdf8;
}

.header-inner {
    max-width: 1180px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 25px;
}

.site-brand {
    font-size: 1.45rem;
    font-weight: 800;
    letter-spacing: 1px;
    color: #ffffff;
}

.site-brand span {
    color: #55d5ff;
}

.site-brand:hover {
    text-decoration: none;
}


/* ---------- NAVIGATION ---------- */

.main-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
}

.main-nav a {
    color: #ffffff;
    font-size: 0.95rem;
    font-weight: 600;
}

.main-nav a:hover {
    color: #55d5ff;
    text-decoration: none;
}


/* ---------- HERO ---------- */

.hero {
    background:
        radial-gradient(circle at 80% 20%, rgba(52, 184, 255, 0.25), transparent 30%),
        linear-gradient(135deg, #061426, #102c50 60%, #163e69);
    color: #ffffff;
    padding: 80px 20px;
}

.hero-inner {
    max-width: 1180px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 55px;
    align-items: center;
}

.hero-content {
    max-width: 720px;
}

.hero-kicker {
    display: inline-block;
    color: #65d9ff;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.hero h1 {
    font-size: clamp(2.7rem, 6vw, 5rem);
    line-height: 1;
    margin-bottom: 22px;
    letter-spacing: -2px;
}

.hero h1 span {
    color: #59d5ff;
}

.hero-subtitle {
    font-size: 1.35rem;
    line-height: 1.5;
    color: #e4f4ff;
    margin-bottom: 25px;
}

.hero-text {
    font-size: 1.08rem;
    color: #d4e3ef;
    margin-bottom: 30px;
}

.hero-image {
    text-align: center;
}

.hero-image img {
    width: 100%;
    max-width: 390px;
    border-radius: 10px;
    box-shadow: 0 25px 55px rgba(0, 0, 0, 0.4);
}


/* ---------- BUTTONS ---------- */

.btn,
.button {
    display: inline-block;
    background: #1479bd;
    color: #ffffff;
    padding: 13px 25px;
    border-radius: 6px;
    font-weight: 700;
    transition: transform 0.2s ease, background 0.2s ease;
}

.btn:hover,
.button:hover {
    background: #0d6098;
    transform: translateY(-2px);
    text-decoration: none;
}

.btn-light {
    background: #ffffff;
    color: #102d55;
}

.btn-light:hover {
    background: #e8f6ff;
}

.btn-outline {
    background: transparent;
    border: 2px solid #5dd6ff;
    color: #ffffff;
}

.btn-outline:hover {
    background: #5dd6ff;
    color: #07162c;
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 25px;
}


/* ---------- MAIN CONTENT ---------- */

.container {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.content-section {
    padding: 65px 0;
}

.content-section.white {
    background: #ffffff;
}

.content-section.dark {
    background: #0a1d35;
    color: #ffffff;
}

.section-heading {
    text-align: center;
    max-width: 780px;
    margin: 0 auto 45px;
}

.section-heading h2 {
    color: #0c3158;
    font-size: clamp(2rem, 4vw, 2.8rem);
    margin-bottom: 12px;
    line-height: 1.15;
}

.dark .section-heading h2 {
    color: #ffffff;
}

.section-heading p {
    color: #607084;
    font-size: 1.08rem;
}

.dark .section-heading p {
    color: #cbd9e6;
}


/* ---------- THREE BOOK DISPLAY ---------- */

.book-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    align-items: stretch;
}

.book-card {
    background: #ffffff;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    box-shadow: 0 8px 28px rgba(18, 45, 75, 0.1);
    border: 1px solid #e0e8f0;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.book-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 15px 38px rgba(18, 45, 75, 0.16);
}

.book-card img {
    width: 100%;
    max-width: 280px;
    margin: 0 auto 20px;
    border-radius: 7px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.16);
}

.book-card h3 {
    color: #0c3158;
    font-size: 1.4rem;
    margin-bottom: 10px;
}

.book-card p {
    color: #5d6875;
    margin-bottom: 20px;
}


/* ---------- INFORMATION / ARTICLE CARDS ---------- */

.info-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.info-card {
    background: #ffffff;
    border: 1px solid #dfe7ef;
    border-radius: 10px;
    padding: 28px;
    box-shadow: 0 6px 20px rgba(20, 45, 70, 0.06);
}

.info-card h3 {
    color: #0c3158;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.info-card p {
    color: #5b6978;
    margin-bottom: 15px;
}

.info-card a {
    font-weight: 700;
}


/* ---------- FEATURE BOX ---------- */

.feature-box {
    max-width: 950px;
    margin: 35px auto;
    background: #eaf7ff;
    border-left: 5px solid #1aa9e8;
    border-radius: 8px;
    padding: 30px 35px;
}

.feature-box h2,
.feature-box h3 {
    color: #0c3158;
    margin-bottom: 12px;
}

.feature-box p:last-child {
    margin-bottom: 0;
}


/* ---------- QUOTE / BIG IDEA ---------- */

.big-idea {
    max-width: 900px;
    margin: 50px auto;
    padding: 35px;
    text-align: center;
    border-top: 1px solid #cddce8;
    border-bottom: 1px solid #cddce8;
}

.big-idea p {
    color: #12395d;
    font-size: clamp(1.4rem, 3vw, 2rem);
    line-height: 1.45;
    font-weight: 700;
}


/* ---------- ARTICLE PAGES ---------- */

.article-header {
    background: linear-gradient(135deg, #07162c, #153f6b);
    color: #ffffff;
    padding: 65px 20px;
    text-align: center;
}

.article-header-inner {
    max-width: 900px;
    margin: 0 auto;
}

.article-header h1 {
    font-size: clamp(2.3rem, 5vw, 3.8rem);
    line-height: 1.12;
    margin-bottom: 18px;
}

.article-header p {
    max-width: 750px;
    margin: 0 auto;
    color: #d8e9f5;
    font-size: 1.2rem;
}

.article {
    max-width: 850px;
    margin: 0 auto;
    background: #ffffff;
    padding: 50px;
    border-radius: 10px;
    box-shadow: 0 6px 25px rgba(20, 40, 65, 0.07);
}

.article h2 {
    color: #103c68;
    font-size: 1.8rem;
    margin: 38px 0 14px;
}

.article h2:first-child {
    margin-top: 0;
}

.article h3 {
    color: #174f7d;
    margin: 28px 0 10px;
}

.article p {
    margin-bottom: 20px;
    font-size: 1.07rem;
}

.article ul,
.article ol {
    margin: 0 0 22px 25px;
}

.article li {
    margin-bottom: 9px;
}


/* ---------- BOOK PROMO INSIDE ARTICLES ---------- */

.book-promo {
    margin: 45px 0;
    padding: 30px;
    background: linear-gradient(135deg, #081a30, #123f6c);
    color: #ffffff;
    border-radius: 10px;
    display: grid;
    grid-template-columns: 160px 1fr;
    gap: 28px;
    align-items: center;
}

.book-promo img {
    width: 160px;
    border-radius: 6px;
}

.book-promo h2,
.book-promo h3 {
    color: #ffffff;
    margin-top: 0;
}

.book-promo p {
    color: #dbe9f4;
}


/* ---------- AUTHOR ---------- */

.author-box {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.author-box h2 {
    color: #103c68;
}


/* ---------- CTA ---------- */

.cta {
    background:
        radial-gradient(circle at 20% 20%, rgba(57, 190, 248, 0.18), transparent 30%),
        #07182d;
    color: #ffffff;
    text-align: center;
    padding: 65px 20px;
}

.cta-inner {
    max-width: 850px;
    margin: 0 auto;
}

.cta h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: 15px;
}

.cta p {
    color: #d4e4ef;
    font-size: 1.12rem;
    margin-bottom: 25px;
}


/* ---------- BREADCRUMBS ---------- */

.breadcrumbs {
    max-width: 1180px;
    margin: 0 auto;
    padding: 15px 20px;
    font-size: 0.9rem;
    color: #68788a;
}

.breadcrumbs a {
    color: #1769aa;
}


/* ---------- FOOTER ---------- */

.site-footer {
    background: #04101f;
    color: #aab9c8;
    padding: 40px 20px;
    text-align: center;
}

.footer-inner {
    max-width: 1100px;
    margin: 0 auto;
}

.site-footer p {
    margin-bottom: 8px;
}

.site-footer a {
    color: #5fd7ff;
}

.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 18px;
    margin-bottom: 20px;
}


/* ---------- UTILITY CLASSES ---------- */

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

.mt-20 {
    margin-top: 20px;
}

.mt-30 {
    margin-top: 30px;
}

.mb-20 {
    margin-bottom: 20px;
}

.mb-30 {
    margin-bottom: 30px;
}

.small-text {
    font-size: 0.9rem;
    color: #718096;
}


/* ---------- RESPONSIVE ---------- */

@media (max-width: 900px) {

    .header-inner {
        flex-direction: column;
        text-align: center;
    }

    .main-nav {
        justify-content: center;
    }

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

    .hero-content {
        margin: 0 auto;
    }

    .hero-image {
        order: -1;
    }

    .hero-image img {
        max-width: 320px;
    }

    .button-row {
        justify-content: center;
    }

    .book-grid,
    .info-grid {
        grid-template-columns: 1fr;
        max-width: 600px;
        margin-left: auto;
        margin-right: auto;
    }

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

    .book-promo img {
        margin: 0 auto;
    }
}


/* ---------- MOBILE ---------- */

@media (max-width: 600px) {

    .site-header {
        padding: 15px;
    }

    .main-nav {
        gap: 10px 15px;
    }

    .hero {
        padding: 50px 18px;
    }

    .hero h1 {
        letter-spacing: -1px;
    }

    .hero-subtitle {
        font-size: 1.15rem;
    }

    .content-section {
        padding: 45px 0;
    }

    .container {
        width: min(100% - 28px, 1180px);
    }

    .article {
        padding: 28px 22px;
        border-radius: 6px;
    }

    .article-header {
        padding: 45px 18px;
    }

    .feature-box {
        padding: 24px 22px;
    }

    .book-card {
        padding: 20px;
    }

    .cta {
        padding: 50px 18px;
    }

    .btn,
    .button {
        width: 100%;
        text-align: center;
    }
}