:root {
    --bg: #ffffff;
    --panel: #f7f7f5;
    --border: rgba(20, 20, 20, 0.1);
    --border-strong: rgba(20, 20, 20, 0.2);
    --fg: #0a0a0a;
    --muted: rgba(20, 20, 20, 0.6);
    --faint: rgba(20, 20, 20, 0.36);
    --accent: #1a73a6;
    --accent-2: #b65a1a;
    --green: #2f7a37;
    --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --sans: "Space Grotesk", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: var(--sans);
    line-height: 1.55;
    overflow-x: hidden;
}

[hidden] {
    display: none !important;
}

a {
    color: inherit;
}

em {
    color: var(--accent);
    font-style: italic;
    font-weight: 300;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(255, 255, 255, 0.86);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(8px);
}

.terminal-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    min-height: 68px;
    padding: 0 40px;
    font-family: var(--mono);
    font-size: 13px;
    color: var(--muted);
}

.repo-mark,
.nav-command,
.nav-links a {
    text-decoration: none;
}

.repo-mark {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--fg);
    white-space: nowrap;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 8px rgba(47, 122, 55, 0.4);
}

.muted,
.prompt-muted {
    color: var(--faint);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
    padding: 0;
    margin: 0;
    list-style: none;
}

.nav-links a,
.nav-command {
    transition: color 160ms ease;
}

.nav-links a:hover,
.nav-command:hover {
    color: var(--accent);
}

.nav-command {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--fg);
    white-space: nowrap;
}

.nav-command span,
.prompt-symbol,
.newsletter-form label {
    color: var(--green);
}

.hero {
    position: relative;
    overflow: hidden;
    padding: 100px 40px 80px;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse at 30% 40%, black 30%, transparent 75%);
    pointer-events: none;
}

.hero-layout {
    position: relative;
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(300px, 1fr);
    gap: 80px;
    max-width: 1280px;
    margin: 0 auto;
}

.eyebrow,
.section-label {
    margin: 0;
    color: var(--accent);
    font-family: var(--mono);
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.18em;
}

.hero h1 {
    margin: 30px 0 0;
    color: var(--fg);
    font-size: clamp(4.6rem, 9vw, 8.4rem);
    font-weight: 500;
    letter-spacing: 0;
    line-height: 0.95;
}

.hero h1 em {
    display: inline-block;
}

.terminal-prompt {
    display: flex;
    align-items: center;
    gap: 8px;
    width: min(100%, 560px);
    min-height: 65px;
    margin-top: 36px;
    padding: 18px 22px;
    overflow: hidden;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--panel);
    color: var(--fg);
    font-family: var(--mono);
    font-size: 15px;
    white-space: nowrap;
}

.typed-command {
    color: var(--accent-2);
}

.cursor {
    display: inline-block;
    width: 0.55em;
    height: 1.05em;
    margin-left: -2px;
    background: var(--accent);
    transform: translateY(0.15em);
    animation: blink 1s steps(2) infinite;
}

.summary {
    max-width: 540px;
    margin: 28px 0 0;
    color: var(--muted);
    font-size: 19px;
    font-weight: 300;
}

.cta-group {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 40px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 22px;
    border-radius: 4px;
    font-family: var(--mono);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: transform 160ms ease, border-color 160ms ease, color 160ms ease;
}

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

.btn-primary {
    border: 1px solid var(--fg);
    background: var(--fg);
    color: var(--bg);
}

.btn-primary::after {
    content: " →";
}

.btn-secondary {
    border: 1px solid var(--border-strong);
    background: transparent;
    color: var(--fg);
}

.book-stage {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 30px;
}

.book-cover {
    position: relative;
    width: min(320px, 72vw);
    aspect-ratio: 2 / 3;
    padding: 30px 26px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    overflow: hidden;
    background: #fff;
    border: 1px solid var(--border-strong);
    box-shadow: 40px 40px 80px rgba(20, 20, 20, 0.14), -2px 0 0 rgba(20, 20, 20, 0.04);
    transform: perspective(1400px) rotateY(-14deg) rotateX(2deg);
    transform-style: preserve-3d;
}

.book-code,
.book-title p,
.book-title small {
    position: relative;
    z-index: 1;
    font-family: var(--mono);
}

.book-code {
    color: var(--faint);
    font-size: 10px;
    letter-spacing: 0.15em;
}

.orbit-mark {
    position: absolute;
    inset: 0;
    display: grid;
    place-items: center;
    pointer-events: none;
}

.orbit-mark::after {
    content: "";
    position: absolute;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent-2);
}

.orbit-mark span {
    position: absolute;
    width: calc(40px + var(--i, 0) * 9px);
    aspect-ratio: 1;
    border: 1px solid rgba(26, 115, 166, 0.58);
    border-radius: 50%;
}

.orbit-mark span:nth-child(1) { --i: 0; opacity: 0.85; }
.orbit-mark span:nth-child(2) { --i: 1; opacity: 0.82; }
.orbit-mark span:nth-child(3) { --i: 2; opacity: 0.79; }
.orbit-mark span:nth-child(4) { --i: 3; opacity: 0.76; border-style: dashed; }
.orbit-mark span:nth-child(5) { --i: 4; opacity: 0.73; }
.orbit-mark span:nth-child(6) { --i: 5; opacity: 0.7; }
.orbit-mark span:nth-child(7) { --i: 6; opacity: 0.67; border-style: dashed; }
.orbit-mark span:nth-child(8) { --i: 7; opacity: 0.64; }
.orbit-mark span:nth-child(9) { --i: 8; opacity: 0.61; }
.orbit-mark span:nth-child(10) { --i: 9; opacity: 0.58; border-style: dashed; }
.orbit-mark span:nth-child(11) { --i: 10; opacity: 0.55; }
.orbit-mark span:nth-child(12) { --i: 11; opacity: 0.52; }
.orbit-mark span:nth-child(13) { --i: 12; opacity: 0.49; border-style: dashed; }
.orbit-mark span:nth-child(14) { --i: 13; opacity: 0.46; }
.orbit-mark span:nth-child(15) { --i: 14; opacity: 0.43; }
.orbit-mark span:nth-child(16) { --i: 15; opacity: 0.4; border-style: dashed; }
.orbit-mark span:nth-child(17) { --i: 16; opacity: 0.37; }
.orbit-mark span:nth-child(18) { --i: 17; opacity: 0.34; }
.orbit-mark span:nth-child(19) { --i: 18; opacity: 0.31; border-style: dashed; }
.orbit-mark span:nth-child(20) { --i: 19; opacity: 0.28; }
.orbit-mark span:nth-child(21) { --i: 20; opacity: 0.25; }
.orbit-mark span:nth-child(22) { --i: 21; opacity: 0.22; border-style: dashed; }
.orbit-mark span:nth-child(23) { --i: 22; opacity: 0.19; }
.orbit-mark span:nth-child(24) { --i: 23; opacity: 0.16; }

.book-title strong,
.book-title em {
    display: block;
    font-size: 38px;
    letter-spacing: 0;
    line-height: 1;
}

.book-title strong {
    font-weight: 500;
}

.book-title span {
    display: block;
    height: 1px;
    margin: 14px 0;
    background: var(--border-strong);
}

.book-title p {
    margin: 0;
    color: var(--muted);
    font-size: 9px;
    letter-spacing: 0.1em;
    line-height: 1.4;
}

.book-title small {
    display: block;
    margin-top: 20px;
    color: var(--faint);
    font-size: 10px;
    letter-spacing: 0.05em;
}

.stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.stats div {
    padding: 24px 32px;
    border-right: 1px solid var(--border);
}

.stats div:last-child {
    border-right: 0;
}

.stats strong {
    display: block;
    color: var(--fg);
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 300;
    letter-spacing: 0;
    line-height: 1;
}

.stats span {
    display: block;
    margin-top: 10px;
    color: var(--muted);
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.section {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 60px;
    padding: 120px 40px;
}

.section > * {
    max-width: 1100px;
}

.lead {
    max-width: 880px;
    margin: 0;
    color: var(--fg);
    font-size: clamp(2rem, 4vw, 3.1rem);
    font-weight: 300;
    letter-spacing: 0;
    line-height: 1.35;
}

.columns {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 60px;
    margin-top: 60px;
}

.columns p,
.author-layout p,
.feature-grid p,
.subscribe-section p {
    color: var(--muted);
    font-size: 16px;
}

.columns p {
    margin: 0;
    line-height: 1.65;
}

.method-section,
.author-section,
.events-section {
    border-top: 1px solid var(--border);
    background: var(--panel);
}

.method-section h2,
.events-heading h2,
.subscribe-section h2 {
    margin: 0;
    color: var(--fg);
    font-size: clamp(2.6rem, 5vw, 4rem);
    font-weight: 400;
    letter-spacing: 0;
    line-height: 1.05;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1px;
    margin-top: 42px;
    border: 1px solid var(--border);
    background: var(--border);
}

.feature-grid article {
    min-height: 270px;
    padding: 26px;
    background: var(--panel);
}

.feature-grid span {
    color: var(--accent);
    font-family: var(--mono);
    font-size: 12px;
}

.feature-grid h3 {
    margin: 56px 0 14px;
    color: var(--fg);
    font-size: 22px;
    font-weight: 500;
    letter-spacing: 0;
    line-height: 1.15;
}

.feature-grid p {
    margin: 0;
    line-height: 1.55;
}

.author-layout {
    display: grid;
    grid-template-columns: 300px minmax(0, 1fr);
    gap: 60px;
}

.author-portrait {
    position: relative;
    aspect-ratio: 3 / 4;
    margin: 0;
    overflow: hidden;
    border: 1px solid var(--border-strong);
    background:
        repeating-linear-gradient(45deg, var(--panel), var(--panel) 10px, var(--bg) 10px, var(--bg) 11px);
}

.author-portrait img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(1) contrast(1.05);
    mix-blend-mode: multiply;
}

.author-layout h2 {
    margin: 0;
    color: var(--fg);
    font-size: clamp(3rem, 6vw, 4.8rem);
    font-weight: 500;
    letter-spacing: 0;
    line-height: 1;
}

.author-layout p {
    max-width: 560px;
    margin: 24px 0 0;
    font-size: 17px;
    line-height: 1.6;
}

.terminal-list {
    max-width: 650px;
    padding: 0;
    margin: 32px 0 0;
    color: var(--muted);
    font-family: var(--mono);
    font-size: 13px;
    list-style: none;
}

.terminal-list li {
    display: flex;
    gap: 14px;
    padding: 10px 0;
    border-top: 1px dashed var(--border);
}

.terminal-list li:first-child {
    border-top: 0;
}

.terminal-list span {
    color: var(--accent);
}

.quote-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
}

.quote-grid blockquote {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 220px;
    margin: 0;
    padding: 32px 28px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--panel);
}

.quote-grid p {
    margin: 0;
    color: var(--fg);
    font-size: 22px;
    font-weight: 400;
    letter-spacing: 0;
    line-height: 1.35;
}

.quote-grid cite {
    margin-top: 24px;
    color: var(--muted);
    font-family: var(--mono);
    font-size: 12px;
    font-style: normal;
    letter-spacing: 0.05em;
}

.events-section {
    display: block;
}

.events-heading {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 60px;
    margin-bottom: 40px;
}

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

.event-list a {
    display: grid;
    grid-template-columns: 120px 80px minmax(0, 1fr) 200px 80px;
    gap: 24px;
    align-items: center;
    padding: 28px 0;
    border-bottom: 1px solid var(--border);
    text-decoration: none;
}

.event-list span,
.event-list b {
    font-family: var(--mono);
    font-size: 13px;
    font-weight: 500;
}

.event-list span:first-child {
    color: var(--accent);
    letter-spacing: 0.08em;
}

.event-list span:nth-child(2),
.event-list small {
    color: var(--muted);
}

.event-list strong {
    color: var(--fg);
    font-size: 22px;
    font-weight: 400;
    letter-spacing: 0;
}

.event-list small {
    font-size: 14px;
}

.event-list b {
    color: var(--fg);
    text-align: right;
}

.subscribe-section {
    position: relative;
    display: block;
    overflow: hidden;
    border-top: 1px solid var(--border);
}

.subscribe-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 80% 20%, rgba(26, 115, 166, 0.1), transparent 50%);
    pointer-events: none;
}

.subscribe-section > div {
    position: relative;
    max-width: 880px;
}

.subscribe-section h2 {
    margin-top: 32px;
}

.subscribe-section p {
    max-width: 600px;
    margin: 24px 0 0;
    font-size: 18px;
    line-height: 1.55;
}

.newsletter-form {
    display: flex;
    max-width: 540px;
    min-height: 56px;
    margin-top: 40px;
    overflow: hidden;
    border: 1px solid var(--border-strong);
    border-radius: 6px;
    background: #fff;
}

.newsletter-form label {
    display: flex;
    align-items: center;
    padding: 0 18px;
    font-family: var(--mono);
    font-size: 14px;
}

.newsletter-form input {
    min-width: 0;
    flex: 1;
    padding: 18px 6px;
    border: 0;
    outline: 0;
    background: transparent;
    color: var(--fg);
    font-family: var(--mono);
    font-size: 14px;
}

.newsletter-form button {
    padding: 0 28px;
    border: 0;
    background: var(--fg);
    color: var(--bg);
    cursor: pointer;
    font-family: var(--mono);
    font-size: 13px;
    font-weight: 500;
}

.newsletter-form button:disabled {
    cursor: wait;
    opacity: 0.7;
}

.newsletter-message {
    min-height: 18px;
    margin-top: 14px;
    color: var(--faint);
    font-family: var(--mono);
    font-size: 12px;
}

.newsletter-message[data-state="success"] {
    color: var(--fg);
}

.newsletter-message[data-state="error"] {
    color: #a7352b;
}

.reader-note {
    display: block;
    margin-top: 16px;
    color: var(--faint);
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.05em;
}

.site-footer {
    display: flex;
    justify-content: space-between;
    gap: 24px;
    padding: 40px;
    border-top: 1px solid var(--border);
    color: var(--faint);
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 0.05em;
}

.site-footer p {
    margin: 0;
}

.site-footer nav {
    display: flex;
    gap: 24px;
}

.site-footer a {
    text-decoration: none;
}

.site-footer a:hover {
    color: var(--accent);
}

.fade-in-section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 600ms ease, transform 600ms ease;
}

.fade-in-section.visible {
    opacity: 1;
    transform: translateY(0);
}

@keyframes blink {
    50% {
        opacity: 0;
    }
}

@media (max-width: 980px) {
    .terminal-nav {
        flex-wrap: wrap;
        padding: 16px 24px;
    }

    .nav-links {
        order: 3;
        width: 100%;
        gap: 18px;
        overflow-x: auto;
    }

    .hero {
        padding: 70px 24px 64px;
    }

    .hero-layout,
    .section,
    .events-heading,
    .author-layout {
        grid-template-columns: 1fr;
        gap: 42px;
    }

    .book-stage {
        justify-content: flex-start;
        order: -1;
        padding-top: 0;
    }

    .feature-grid,
    .quote-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .event-list a {
        grid-template-columns: 90px 60px minmax(0, 1fr);
    }

    .event-list small,
    .event-list b {
        grid-column: 3;
    }

    .section,
    .events-section,
    .subscribe-section {
        padding: 88px 24px;
    }
}

@media (max-width: 640px) {
    .terminal-nav {
        font-size: 12px;
    }

    .nav-command {
        display: none;
    }

    .hero h1 {
        font-size: 4rem;
    }

    .terminal-prompt {
        align-items: flex-start;
        min-height: 0;
        white-space: normal;
    }

    .stats,
    .columns,
    .feature-grid,
    .quote-grid {
        grid-template-columns: 1fr;
    }

    .stats div {
        border-right: 0;
        border-bottom: 1px solid var(--border);
    }

    .stats div:last-child {
        border-bottom: 0;
    }

    .author-layout {
        gap: 30px;
    }

    .author-portrait {
        max-width: 280px;
    }

    .event-list a {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .event-list small,
    .event-list b {
        grid-column: auto;
    }

    .event-list b {
        text-align: left;
    }

    .newsletter-form {
        flex-wrap: wrap;
    }

    .newsletter-form label {
        min-height: 54px;
    }

    .newsletter-form button {
        width: 100%;
        min-height: 54px;
    }

    .site-footer {
        flex-direction: column;
    }

    .site-footer nav {
        flex-wrap: wrap;
    }
}