/* =========================
   BASIC RESET
========================= */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background: #f8f7f4;
    color: #1d1d1d;
    line-height: 1.6;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
}

button {
    font-family: inherit;
}


/* =========================
   VARIABLES
========================= */

:root {
    --primary: #171717;
    --secondary: #666666;
    --background: #f8f7f4;
    --white: #ffffff;
    --light: #eeeeeb;
    --border: #ddddda;
}


/* =========================
   NAVIGATION
========================= */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(248, 247, 244, 0.96);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.navbar {
    max-width: 1200px;
    margin: auto;
    padding: 20px 30px;

    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    text-decoration: none;
    font-size: 22px;
    font-weight: 800;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav-links a {
    text-decoration: none;
    font-size: 14px;
    transition: 0.3s;
}

.nav-links a:hover {
    opacity: 0.6;
}

.nav-button {
    background: var(--primary);
    color: white;
    padding: 11px 20px;
    border-radius: 6px;
}

.menu-toggle {
    display: none;
    border: none;
    background: transparent;
    font-size: 26px;
    cursor: pointer;
}


/* =========================
   HERO
========================= */

.hero {
    max-width: 1200px;
    min-height: 85vh;
    margin: auto;
    padding: 80px 30px;

    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 70px;
}

.hero-content {
    max-width: 650px;
}

.eyebrow {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 3px;
    margin-bottom: 18px;
}

.hero h1 {
    font-size: clamp(48px, 7vw, 82px);
    line-height: 0.98;
    margin-bottom: 28px;
    letter-spacing: -3px;
}

.hero h1 span {
    display: block;
    font-weight: 400;
}

.hero-description {
    max-width: 560px;
    font-size: 18px;
    color: var(--secondary);
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.button {
    display: inline-block;
    padding: 14px 24px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 700;
    transition: 0.3s;
}

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

.primary-button:hover {
    transform: translateY(-2px);
}

.secondary-button {
    border: 1px solid var(--primary);
}

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

.hero-book {
    position: relative;

    display: flex;
    justify-content: center;
    align-items: center;
}

.book-cover {
    width: 370px;
    max-width: 100%;
    position: relative;
    z-index: 2;

    border-radius: 5px;

    box-shadow:
        20px 25px 50px rgba(0, 0, 0, 0.18);
}

.book-shadow {
    position: absolute;
    width: 280px;
    height: 40px;
    bottom: -10px;

    background: rgba(0, 0, 0, 0.18);
    filter: blur(20px);
}


/* =========================
   GENERAL SECTIONS
========================= */

.section {
    max-width: 1150px;
    margin: auto;
    padding: 110px 30px;
}

.section-heading {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-heading h2 {
    font-size: clamp(36px, 5vw, 55px);
    line-height: 1.1;
    letter-spacing: -1px;
}

.heading-description {
    margin-top: 18px;
    color: var(--secondary);
}


/* =========================
   ABOUT
========================= */

.about-section {
    background: white;
    max-width: none;
}

.about-grid {
    max-width: 1050px;
    margin: auto;

    display: grid;
    grid-template-columns: 0.8fr 1.2fr;

    gap: 80px;
    align-items: center;
}

.about-image img {
    width: 100%;
    max-width: 380px;
    margin: auto;

    box-shadow:
        15px 20px 40px rgba(0, 0, 0, 0.12);
}

.about-content h3 {
    font-size: 32px;
    margin-bottom: 20px;
}

.about-content > p {
    color: var(--secondary);
    margin-bottom: 20px;
}

.benefits {
    margin-top: 35px;
}

.benefit {
    display: flex;
    gap: 20px;

    padding: 20px 0;

    border-top: 1px solid var(--border);
}

.benefit span {
    font-weight: 800;
    font-size: 13px;
}

.benefit h4 {
    margin-bottom: 5px;
}

.benefit p {
    color: var(--secondary);
    font-size: 14px;
}


/* =========================
   CONTENTS
========================= */

.contents-section {
    max-width: none;
    background: var(--light);
}

.chapter-grid {
    max-width: 1050px;
    margin: auto;

    display: grid;
    grid-template-columns: repeat(2, 1fr);

    gap: 20px;
}

.chapter-card {
    background: white;

    padding: 35px;

    border: 1px solid var(--border);

    transition: 0.3s;
}

.chapter-card:hover {
    transform: translateY(-5px);
}

.chapter-number {
    font-size: 13px;
    font-weight: 800;
}

.chapter-card h3 {
    font-size: 24px;
    margin: 18px 0 10px;
}

.chapter-card p {
    color: var(--secondary);
}


/* =========================
   BOOK PREVIEW
========================= */

.preview-grid {
    max-width: 1000px;
    margin: auto;

    display: grid;
    grid-template-columns: repeat(3, 1fr);

    gap: 20px;
}

.preview-card {
    background: white;

    border: 1px solid var(--border);

    overflow: hidden;
}

.preview-card img {
    width: 100%;
    transition: 0.4s;
}

.preview-card:hover img {
    transform: scale(1.03);
}


/* =========================
   AUTHOR
========================= */

.author-section {
    background: var(--primary);
    color: white;

    padding: 110px 30px;
}

.author-container {
    max-width: 1000px;
    margin: auto;

    display: grid;
    grid-template-columns: 300px 1fr;

    gap: 70px;

    align-items: center;
}

.author-image img {
    width: 100%;
    border-radius: 8px;
}

.author-content h2 {
    font-size: clamp(40px, 6vw, 60px);
    margin-bottom: 25px;
    line-height: 1;
}

.author-content p:not(.eyebrow) {
    color: #c9c9c9;
    margin-bottom: 20px;
}


/* =========================
   TESTIMONIAL
========================= */

.testimonial-section {
    background: white;
    max-width: none;
}

.testimonial-grid {
    max-width: 1050px;
    margin: auto;

    display: grid;
    grid-template-columns: repeat(3, 1fr);

    gap: 20px;
}

.testimonial {
    padding: 35px;

    background: var(--background);

    border: 1px solid var(--border);
}

.stars {
    margin-bottom: 20px;
    letter-spacing: 3px;
}

.testimonial p {
    color: var(--secondary);
    margin-bottom: 25px;
}


/* =========================
   BUY SECTION
========================= */

.buy-section {
    background: var(--light);
    text-align: center;

    padding: 110px 30px;
}

.buy-container {
    max-width: 700px;
    margin: auto;
}

.buy-container h2 {
    font-size: clamp(40px, 6vw, 65px);
    line-height: 1;
    margin-bottom: 25px;
}

.buy-description {
    color: var(--secondary);
}

.price {
    font-size: 48px;
    font-weight: 800;
    margin-top: 25px;
}

.price-note {
    color: var(--secondary);
    font-size: 14px;
    margin-bottom: 30px;
}

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

.purchase-button:hover {
    transform: translateY(-2px);
}


/* =========================
   FAQ
========================= */

.faq-container {
    max-width: 800px;
    margin: auto;
}

.faq-item {
    border-bottom: 1px solid var(--border);
}

.faq-question {
    width: 100%;

    border: none;
    background: transparent;

    padding: 25px 0;

    display: flex;
    justify-content: space-between;
    align-items: center;

    cursor: pointer;

    font-size: 17px;
    font-weight: 700;

    text-align: left;
}

.faq-icon {
    font-size: 25px;
    font-weight: 400;
}

.faq-answer {
    display: none;

    padding: 0 0 25px;

    color: var(--secondary);
}

.faq-answer.active {
    display: block;
}


/* =========================
   FOOTER
========================= */

footer {
    background: #111;
    color: white;

    text-align: center;

    padding: 50px 30px;
}

.footer-content h3 {
    font-size: 22px;
    margin-bottom: 10px;
}

.footer-content > p {
    color: #aaa;
}

.footer-links {
    display: flex;
    justify-content: center;

    gap: 25px;

    margin: 25px 0;
}

.footer-links a {
    text-decoration: none;
    font-size: 14px;
}

.copyright {
    font-size: 13px;
}


/* =========================
   TABLET & MOBILE
========================= */

@media (max-width: 800px) {

    .menu-toggle {
        display: block;
    }

    .nav-links {
        display: none;

        position: absolute;

        top: 72px;
        left: 0;

        width: 100%;

        background: var(--background);

        padding: 25px 30px;

        flex-direction: column;

        align-items: stretch;

        gap: 15px;

        border-bottom: 1px solid var(--border);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 10px 0;
    }


    .hero {
        grid-template-columns: 1fr;

        text-align: center;

        padding-top: 60px;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-buttons {
        justify-content: center;
    }


    .about-grid {
        grid-template-columns: 1fr;

        gap: 50px;
    }


    .chapter-grid {
        grid-template-columns: 1fr;
    }


    .preview-grid {
        grid-template-columns: 1fr;
    }


    .author-container {
        grid-template-columns: 1fr;

        text-align: center;

        gap: 40px;
    }

    .author-image img {
        max-width: 300px;
        margin: auto;
    }


    .testimonial-grid {
        grid-template-columns: 1fr;
    }


    .section {
        padding: 80px 25px;
    }
}


/* =========================
   SMALL PHONE
========================= */

@media (max-width: 500px) {

    .navbar {
        padding: 18px 20px;
    }

    .hero {
        padding-left: 20px;
        padding-right: 20px;
    }

    .hero h1 {
        letter-spacing: -2px;
    }

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

    .hero-buttons {
        width: 100%;
    }

    .footer-links {
        flex-direction: column;
        gap: 10px;
    }
}