/* =========================================================
   DELAUNAY BOOK
   Editorial / Art Book / Scholarly Publication
   ========================================================= */

:root {
    --paper: #f5f3ee;
    --ink: #171717;
    --muted: #6f6d68;
    --line: #d7d3ca;
    --accent: #8b3f32;

    --serif: "Cormorant Garamond", Georgia, serif;
    --sans: "Inter", Arial, sans-serif;

    --page-width: 1440px;
    --text-width: 760px;

    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 7rem;
    --space-xxl: 11rem;
}


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

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 1.2rem;
    font-weight: 300;
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

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

button,
a {
    -webkit-tap-highlight-color: transparent;
}


/* =========================================================
   GLOBAL TYPOGRAPHY
   ========================================================= */

p,
h1,
h2,
h3 {
    margin-top: 0;
}

p {
    margin-bottom: 1.75rem;
}

em {
    font-family: var(--serif);
    font-style: italic;
    font-weight: 400;
}


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

.site-nav {
    width: 100%;
    border-bottom: 1px solid var(--line);
}

.nav-inner {
    width: min(100% - 4rem, var(--page-width));
    min-height: 78px;
    margin: 0 auto;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.nav-brand {
    font-family: var(--serif);
    font-size: 1.55rem;
    font-weight: 500;
    letter-spacing: 0.015em;
}

.nav-meta {
    color: var(--muted);
    font-size: 0.82rem;
    font-weight: 400;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}


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

.hero {
    width: min(100% - 4rem, var(--page-width));
    min-height: calc(100vh - 79px);
    margin: 0 auto;

    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(280px, 0.65fr);
    align-items: center;
    gap: clamp(4rem, 10vw, 12rem);

    padding: var(--space-xxl) 0;
}

.hero-copy {
    max-width: 900px;
}

.kicker {
    margin-bottom: 1.75rem;

    color: var(--muted);
    font-size: 0.82rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    line-height: 1.4;
    text-transform: uppercase;
}

.hero-title {
    max-width: 850px;
    margin-bottom: 1.75rem;

    font-family: var(--serif);
    font-size: clamp(5.5rem, 10vw, 10.5rem);
    font-weight: 300;
    letter-spacing: -0.045em;
    line-height: 0.84;
}

.hero-title em {
    display: inline-block;
}

.hero-subtitle {
    max-width: 680px;
    margin: 0;

    color: var(--muted);
    font-family: var(--serif);
    font-size: clamp(1.7rem, 2.5vw, 2.55rem);
    font-weight: 400;
    line-height: 1.15;
}

.hero-index {
    align-self: end;
    max-width: 360px;
    padding-bottom: 1rem;
}

.hero-index-number {
    margin-bottom: 1.4rem;

    font-size: 0.82rem;
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.hero-index-text {
    margin: 0;

    color: var(--muted);
    font-size: 1.15rem;
    line-height: 1.8;
}


/* =========================================================
   SHARED SECTION LABEL
   ========================================================= */

.section-label {
    margin: 0;

    font-size: 0.82rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    line-height: 1.4;
    text-transform: uppercase;
}


/* =========================================================
   INTRODUCTION
   ========================================================= */

.intro {
    border-top: 1px solid var(--line);
}

.intro-grid {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    display: grid;
    grid-template-columns: minmax(180px, 0.6fr) minmax(0, 1.4fr);
    gap: clamp(4rem, 10vw, 12rem);

    padding: var(--space-xxl) 0;
}

.intro-lead {
    max-width: var(--text-width);
    margin-bottom: 2.75rem;

    font-family: var(--serif);
    font-size: clamp(2.3rem, 4vw, 4rem);
    font-weight: 300;
    letter-spacing: -0.02em;
    line-height: 1.05;
}

.intro-copy {
    max-width: 720px;
    margin-bottom: 0;

    color: var(--muted);
    font-size: 1.2rem;
    line-height: 1.9;
}


/* =========================================================
   BOOK DATA
   ========================================================= */

.book-data {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);

    display: grid;
    grid-template-columns: repeat(4, 1fr);
}

.data-item {
    min-height: 170px;
    padding: 2.25rem 1.75rem;

    display: flex;
    flex-direction: column;
    justify-content: space-between;

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

.data-item:first-child {
    padding-left: 0;
}

.data-item:last-child {
    padding-right: 0;
    border-right: 0;
}

.data-label {
    color: var(--muted);
    font-size: 0.76rem;
    font-weight: 500;
    letter-spacing: 0.17em;
    text-transform: uppercase;
}

.data-value {
    font-family: var(--serif);
    font-size: 1.7rem;
    font-weight: 400;
    line-height: 1.1;
}


/* =========================================================
   STUDY / CHAPTER INDEX
   ========================================================= */

.index {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    padding: var(--space-xxl) 0;
}

.index-head {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.7fr);
    gap: clamp(4rem, 10vw, 12rem);

    padding-bottom: var(--space-xl);
}

.index-title {
    max-width: 700px;
    margin: 1.75rem 0 0;

    font-family: var(--serif);
    font-size: clamp(4rem, 6.5vw, 7.4rem);
    font-weight: 300;
    letter-spacing: -0.04em;
    line-height: 0.88;
}

.index-note {
    align-self: end;
    max-width: 420px;
    margin: 0;

    color: var(--muted);
    font-size: 1.12rem;
    line-height: 1.8;
}

.theme-list {
    border-top: 1px solid var(--line);
}

.theme {
    position: relative;

    display: grid;
    grid-template-columns: 110px minmax(280px, 0.8fr) minmax(260px, 0.7fr);
    gap: 2.5rem;

    padding: 3.25rem 0;

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

.theme-number {
    color: var(--muted);
    font-family: var(--serif);
    font-size: 2.6rem;
    font-weight: 300;
    line-height: 1;
}

.theme-title {
    max-width: 560px;
    margin: 0;

    font-family: var(--serif);
    font-size: clamp(2rem, 3.2vw, 3.3rem);
    font-weight: 400;
    letter-spacing: -0.02em;
    line-height: 1.02;
}

.theme-description {
    max-width: 430px;
    margin: 0;

    color: var(--muted);
    font-size: 1.08rem;
    line-height: 1.8;
}


/* =========================================================
   FEATURE — SONIA DELAUNAY
   ========================================================= */

.feature {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    padding-bottom: var(--space-xxl);
}

.feature-box {
    min-height: 680px;
    padding: clamp(3rem, 8vw, 8rem);

    display: flex;
    align-items: center;

    background: var(--ink);
    color: var(--paper);
}

.feature-copy {
    max-width: 900px;
}

.feature .kicker {
    color: #aaa79f;
}

.feature-title {
    margin-bottom: 2.25rem;

    font-family: var(--serif);
    font-size: clamp(4.7rem, 8.5vw, 8.8rem);
    font-weight: 300;
    letter-spacing: -0.045em;
    line-height: 0.86;
}

.feature-text {
    max-width: 680px;
    margin: 0;

    color: #c5c1b8;
    font-size: 1.2rem;
    line-height: 1.9;
}


/* =========================================================
   CENTRAL IDEA
   ========================================================= */

.structure {
    border-top: 1px solid var(--line);
}

.structure-grid {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    display: grid;
    grid-template-columns: minmax(180px, 0.6fr) minmax(0, 1.4fr);
    gap: clamp(4rem, 10vw, 12rem);

    padding: var(--space-xxl) 0;
}

.structure-copy {
    max-width: var(--text-width);
}

.structure-copy p {
    margin-bottom: 2.5rem;

    font-family: var(--serif);
    font-size: clamp(1.9rem, 2.8vw, 2.8rem);
    font-weight: 300;
    letter-spacing: -0.015em;
    line-height: 1.18;
}

.structure-copy p:last-child {
    margin-bottom: 0;
}


/* =========================================================
   PURCHASE
   ========================================================= */

.purchase {
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.purchase-grid {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;

    min-height: 580px;

    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
    align-items: center;
    gap: 6rem;

    padding: var(--space-xxl) 0;
}

.purchase-title {
    max-width: 750px;
    margin: 1.75rem 0;

    font-family: var(--serif);
    font-size: clamp(4rem, 6.5vw, 7rem);
    font-weight: 300;
    letter-spacing: -0.04em;
    line-height: 0.9;
}

.purchase-copy {
    max-width: 620px;
    margin: 0;

    color: var(--muted);
    font-family: var(--serif);
    font-size: 1.55rem;
    line-height: 1.35;
}

.purchase-link {
    min-height: 82px;
    padding: 0 1.75rem;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;

    border-top: 1px solid var(--ink);
    border-bottom: 1px solid var(--ink);

    font-size: 0.82rem;
    font-weight: 500;
    letter-spacing: 0.16em;
    text-transform: uppercase;

    transition:
        background-color 180ms ease,
        color 180ms ease,
        padding 180ms ease;
}

.purchase-link span:last-child {
    font-size: 1.4rem;
    font-weight: 300;
    letter-spacing: 0;
}

.purchase-link:hover {
    padding-left: 2.25rem;
    padding-right: 2.25rem;

    background: var(--ink);
    color: var(--paper);
}


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

.footer {
    width: min(100% - 4rem, var(--page-width));
    margin: 0 auto;
}

.footer-top {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;

    padding: var(--space-xl) 0;

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

.footer-heading {
    margin-bottom: 1.2rem;

    font-size: 0.76rem;
    font-weight: 500;
    letter-spacing: 0.17em;
    text-transform: uppercase;
}

.footer-link {
    color: var(--muted);
    font-size: 1.05rem;

    transition: color 180ms ease;
}

.footer-link:hover {
    color: var(--ink);
}

.footer-bottom {
    min-height: 100px;

    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;

    color: var(--muted);
    font-size: 0.76rem;
    font-weight: 400;
    letter-spacing: 0.13em;
    text-transform: uppercase;
}


/* =========================================================
   FOCUS STATES
   ========================================================= */

a:focus-visible {
    outline: 1px solid var(--ink);
    outline-offset: 6px;
}


/* =========================================================
   RESPONSIVE — TABLET
   ========================================================= */

@media (max-width: 1000px) {

    :root {
        --space-xl: 5rem;
        --space-xxl: 8rem;
    }

    .hero {
        grid-template-columns: 1fr;
        gap: 5rem;
    }

    .hero-index {
        align-self: auto;
        max-width: 520px;
        margin-left: auto;
    }

    .intro-grid,
    .structure-grid {
        grid-template-columns: 1fr;
        gap: 4rem;
    }

    .index-head {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .index-note {
        max-width: 600px;
    }

    .theme {
        grid-template-columns: 80px 1fr;
    }

    .theme-description {
        grid-column: 2;
        max-width: 600px;
    }

    .purchase-grid {
        grid-template-columns: 1fr;
        gap: 4rem;
    }

    .purchase-link {
        max-width: 560px;
    }
}


/* =========================================================
   RESPONSIVE — MOBILE
   ========================================================= */

@media (max-width: 700px) {

    :root {
        --space-lg: 3rem;
        --space-xl: 4rem;
        --space-xxl: 6rem;
    }

    body {
        font-size: 1rem;
    }

    .nav-inner,
    .hero,
    .intro-grid,
    .book-data,
    .index,
    .feature,
    .structure-grid,
    .purchase-grid,
    .footer {
        width: min(100% - 2.5rem, var(--page-width));
    }

    .nav-inner {
        min-height: 64px;
    }

    .nav-brand {
        font-size: 1.4rem;
    }

    .nav-meta {
        display: none;
    }

    .hero {
        min-height: auto;
        padding-top: 7rem;
        padding-bottom: 7rem;
    }

    .hero-title {
        font-size: clamp(4rem, 17vw, 6.5rem);
    }

    .hero-subtitle {
        font-size: 1.5rem;
    }

    .hero-index {
        margin-left: 0;
    }

    .hero-index-text {
        font-size: 1rem;
    }

    .intro-grid,
    .structure-grid {
        gap: 2.5rem;
    }

    .intro-lead {
        font-size: 2rem;
    }

    .intro-copy {
        font-size: 1rem;
    }

    .book-data {
        display: block;
    }

    .data-item,
    .data-item:first-child,
    .data-item:last-child {
        min-height: auto;
        padding: 1.5rem 0;

        display: flex;
        flex-direction: row;
        align-items: baseline;
        justify-content: space-between;
        gap: 1.5rem;

        border-right: 0;
        border-bottom: 1px solid var(--line);
    }

    .data-item:last-child {
        border-bottom: 0;
    }

    .data-value {
        text-align: right;
        font-size: 1.25rem;
    }

    .index-title {
        font-size: clamp(3.2rem, 15vw, 5rem);
    }

    .theme {
        grid-template-columns: 50px 1fr;
        gap: 1rem;

        padding: 2.5rem 0;
    }

    .theme-number {
        font-size: 1.5rem;
    }

    .theme-title {
        font-size: 2rem;
    }

    .theme-description {
        grid-column: 2;
        font-size: 0.98rem;
    }

    .feature-box {
        min-height: 500px;
        padding: 3rem 2rem;
    }

    .feature-title {
        font-size: clamp(3.8rem, 16vw, 6rem);
    }

    .feature-text {
        font-size: 1rem;
    }

    .structure-copy p {
        font-size: 1.7rem;
    }

    .purchase-title {
        font-size: clamp(3.3rem, 15vw, 5.5rem);
    }

    .purchase-copy {
        font-size: 1.3rem;
    }

    .purchase-link {
        min-height: 68px;
        font-size: 0.72rem;
    }

    .footer-top {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }

    .footer-link {
        font-size: 0.95rem;
    }

    .footer-bottom {
        min-height: auto;
        padding: 1.5rem 0;

        align-items: flex-start;
        flex-direction: column;
        gap: 0.65rem;
    }
}


/* =========================================================
   REDUCED MOTION
   ========================================================= */

@media (prefers-reduced-motion: reduce) {

    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition: none !important;
    }
   }