@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+Bengali:wght@400;500;600;700&family=Playfair+Display:wght@500;600;700&display=swap');

:root {
    --bg: #07131f;
    --bg-soft: #0c1d2c;
    --surface: #102638;
    --text: #f5f7f8;
    --muted: #a9b7c2;
    --accent: #d7b56d;
    --line: rgba(255, 255, 255, 0.1);
    --max-width: 1160px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: "Noto Serif Bengali", serif;
    line-height: 1.8;
}

a {
    color: inherit;
    text-decoration: none;
}

.container {
    width: min(90%, var(--max-width));
    margin: 0 auto;
}

.narrow {
    max-width: 780px;
}

/* Header */

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(7, 19, 31, 0.88);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
}

.nav-container {
    min-height: 74px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: "Playfair Display", serif;
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.02em;
}

.navigation {
    display: flex;
    gap: 34px;
}

.navigation a {
    color: var(--muted);
    font-family: Arial, sans-serif;
    font-size: 0.9rem;
    transition: color 0.25s ease;
}

.navigation a:hover {
    color: var(--text);
}

.menu-toggle {
    display: none;
    border: 0;
    background: transparent;
    color: var(--text);
    font-size: 1.6rem;
    cursor: pointer;
}

/* Hero */

.hero {
    min-height: calc(100vh - 74px);
    display: flex;
    align-items: center;
    padding: 90px 0;
    background:
        radial-gradient(circle at 80% 20%, rgba(32, 91, 130, 0.25), transparent 35%),
        linear-gradient(145deg, var(--bg), var(--bg-soft));
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 80px;
}

.eyebrow,
.section-label {
    color: var(--accent);
    font-family: Arial, sans-serif;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.hero h1 {
    margin: 18px 0 8px;
    font-size: clamp(3rem, 6vw, 5.7rem);
    line-height: 1.18;
    font-weight: 600;
    letter-spacing: -0.04em;
}

.hero-author {
    color: var(--muted);
    font-family: "Playfair Display", serif;
    font-size: 1.15rem;
    margin-bottom: 24px;
}

.hero-description {
    max-width: 600px;
    color: var(--muted);
    font-size: 1.02rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 34px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 50px;
    padding: 0 24px;
    border-radius: 5px;
    font-family: Arial, sans-serif;
    font-size: 0.86rem;
    font-weight: 700;
    transition:
        transform 0.25s ease,
        background 0.25s ease,
        border-color 0.25s ease;
}

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

.btn-primary {
    background: var(--accent);
    color: #101820;
}

.btn-secondary {
    border: 1px solid var(--line);
    color: var(--text);
}

.btn-secondary:hover {
    border-color: rgba(255, 255, 255, 0.3);
}

/* Cover */

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

.cover-frame {
    width: min(100%, 360px);
    padding: 10px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.12);
    box-shadow: 0 30px 70px rgba(0, 0, 0, 0.35);
}

.cover-placeholder {
    aspect-ratio: 2 / 3;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    background: #123149;
    color: var(--accent);
    font-family: Arial, sans-serif;
    letter-spacing: 0.08em;
}

.cover-frame img {
    display: block;
    width: 100%;
    height: auto;
}
}

/* Sections */

.book-section,
.about-section,
.contact-section {
    padding: 120px 0;
}

.book-section {
    background: #091925;
}

.about-section {
    background: var(--bg);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.contact-section {
    background: var(--bg-soft);
}

h2 {
    margin-top: 14px;
    font-size: clamp(2rem, 4vw, 3.4rem);
    line-height: 1.35;
    font-weight: 600;
}

.divider {
    width: 58px;
    height: 2px;
    margin: 28px 0 34px;
    background: var(--accent);
}

.book-description {
    margin-bottom: 22px;
    color: var(--muted);
    font-size: 1rem;
}

.book-section .btn {
    margin-top: 20px;
}

.disabled-button {
    opacity: 0.65;
    pointer-events: none;
}

.coming-soon {
    margin-top: 12px;
    color: #71818d;
    font-family: Arial, sans-serif;
    font-size: 0.75rem;
}

/* About */

.about-grid {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 80px;
}

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

.about-text p {
    margin-bottom: 22px;
}

/* Contact */

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

.contact-box p:not(.section-label) {
    margin-top: 18px;
    color: var(--muted);
}

.email-link {
    display: inline-block;
    margin-top: 14px;
    color: var(--accent);
    font-family: Arial, sans-serif;
    font-size: 1rem;
    border-bottom: 1px solid rgba(215, 181, 109, 0.4);
}

/* Footer */

.site-footer {
    padding: 28px 0;
    border-top: 1px solid var(--line);
    background: #050e16;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    color: #71818d;
    font-family: Arial, sans-serif;
    font-size: 0.75rem;
}

.footer-content a:hover {
    color: var(--text);
}

/* Mobile */

@media (max-width: 800px) {

    .navigation {
        position: absolute;
        top: 74px;
        left: 0;
        width: 100%;
        display: none;
        flex-direction: column;
        gap: 0;
        padding: 10px 5%;
        background: rgba(7, 19, 31, 0.98);
        border-bottom: 1px solid var(--line);
    }

    .navigation.active {
        display: flex;
    }

    .navigation a {
        padding: 14px 0;
        border-bottom: 1px solid var(--line);
    }

    .menu-toggle {
        display: block;
    }

    .hero {
        min-height: auto;
        padding: 70px 0 90px;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }

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

    .hero-description {
        margin: 0 auto;
    }

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

    .hero-cover {
        order: -1;
    }

    .cover-frame {
        width: min(72vw, 320px);
    }

    .book-section,
    .about-section,
    .contact-section {
        padding: 85px 0;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 35px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}