/* ========================================
   OBERFELD PRESS — Main Stylesheet
   ======================================== */

/* ----------------------------------------
   CSS CUSTOM PROPERTIES
   ---------------------------------------- */
:root {
    /* Warm monochrome palette - no pure black or white */
    --color-bg: #F7F5F2;
    --color-bg-alt: #EFECE7;
    --color-text: #1A1917;
    --color-text-secondary: #6B6965;
    --color-text-tertiary: #9B9792;
    --color-border: #D8D4CE;
    --color-accent: #0FFCBE;
    --color-accent-hover: #00E5A8;
    
    /* Typography */
    --font-sans: 'Instrument Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-serif: 'Newsreader', Georgia, serif;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
    
    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-medium: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ----------------------------------------
   RESET & BASE
   ---------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    margin: 0;
    padding: 0;
}

::selection {
    background: var(--color-accent);
    color: var(--color-text);
}

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

/* ----------------------------------------
   HEADER & NAVIGATION
   ---------------------------------------- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-sm) var(--space-md);
    background: transparent;
    transition: background var(--transition-medium), backdrop-filter var(--transition-medium);
}

.site-header.scrolled {
    background: rgba(247, 245, 242, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1600px;
    margin: 0 auto;
}

.logo {
    height: 36px;
    width: auto;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.7;
}

/* Menu Toggle Button */
.menu-toggle {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-xs) 0;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--color-text);
    transition: color var(--transition-fast);
}

.menu-toggle:hover {
    color: var(--color-text-secondary);
}

.menu-toggle-lines {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 24px;
}

.menu-toggle-line {
    height: 2px;
    background: currentColor;
    transition: transform var(--transition-medium), opacity var(--transition-medium), width var(--transition-medium);
}

.menu-toggle-line:nth-child(1) { width: 100%; }
.menu-toggle-line:nth-child(2) { width: 70%; }

.menu-toggle.active .menu-toggle-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active .menu-toggle-line:nth-child(2) {
    transform: translateY(0) rotate(-45deg);
    width: 100%;
}

/* Navigation Panel */
.nav-panel {
    position: fixed;
    top: 0;
    right: 0;
    width: 100%;
    max-width: 600px;
    height: 100vh;
    height: 100dvh;
    background: var(--color-text);
    color: var(--color-bg);
    z-index: 99;
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: var(--space-xl) var(--space-lg);
}

.nav-panel.open {
    transform: translateX(0);
}

.nav-panel-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 25, 23, 0.4);
    z-index: 98;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-medium);
}

.nav-panel-overlay.visible {
    opacity: 1;
    pointer-events: auto;
}

.nav-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-links li {
    overflow: hidden;
}

.nav-links a {
    display: block;
    font-family: var(--font-serif);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 400;
    color: var(--color-bg);
    text-decoration: none;
    padding: var(--space-xs) 0;
    transform: translateY(100%);
    opacity: 0;
    transition: transform var(--transition-medium), opacity var(--transition-medium), color var(--transition-fast);
}

.nav-panel.open .nav-links a {
    transform: translateY(0);
    opacity: 1;
}

.nav-panel.open .nav-links li:nth-child(1) a { transition-delay: 0.1s; }
.nav-panel.open .nav-links li:nth-child(2) a { transition-delay: 0.15s; }
.nav-panel.open .nav-links li:nth-child(3) a { transition-delay: 0.2s; }
.nav-panel.open .nav-links li:nth-child(4) a { transition-delay: 0.25s; }

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

.nav-panel-footer {
    margin-top: var(--space-lg);
    padding-top: var(--space-md);
    border-top: 1px solid rgba(247, 245, 242, 0.2);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--transition-medium) 0.3s, transform var(--transition-medium) 0.3s;
}

.nav-panel.open .nav-panel-footer {
    opacity: 1;
    transform: translateY(0);
}

.nav-panel-footer p {
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
    margin: 0;
    line-height: 1.8;
}

.nav-panel-footer a {
    color: var(--color-bg);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ----------------------------------------
   HERO SECTION
   ---------------------------------------- */
.hero {
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding: var(--space-xl) 0;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    opacity: 0.5;
    pointer-events: none;
    overflow: hidden;
}

.hero-background img {
    position: absolute;
    bottom: -15%;
    left: -5%;
    width: 110%;
    height: auto;
    min-width: 1000px;
    animation: undulate 25s ease-in-out infinite;
    transform-origin: center bottom;
}

@keyframes undulate {
    0%, 100% {
        transform: translateY(0) translateX(0) scale(1);
    }
    25% {
        transform: translateY(-1.5%) translateX(0.5%) scale(1.01);
    }
    50% {
        transform: translateY(-2.5%) translateX(0) scale(1.02);
    }
    75% {
        transform: translateY(-1%) translateX(-0.5%) scale(1.01);
    }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

.hero-tagline {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
    opacity: 0;
    animation: fadeInUp 1s ease forwards 0.2s;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 5rem);
    font-weight: 400;
    line-height: 1.1;
    margin: 0 0 var(--space-md) 0;
    max-width: 900px;
    opacity: 0;
    animation: fadeInUp 1s ease forwards 0.4s;
}

.hero-description {
    font-family: var(--font-serif);
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    font-weight: 400;
    font-style: italic;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 0 var(--space-lg) 0;
    opacity: 0;
    animation: fadeInUp 1s ease forwards 0.6s;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.scroll-indicator {
    position: absolute;
    bottom: var(--space-md);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-text-secondary);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    opacity: 0;
    animation: fadeIn 1s ease forwards 1s;
}

@keyframes fadeIn {
    to { opacity: 1; }
}

.scroll-indicator-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--color-text-secondary), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { transform: scaleY(1); opacity: 1; }
    50% { transform: scaleY(0.6); opacity: 0.5; }
}

/* ----------------------------------------
   FEATURED TITLE SECTION
   ---------------------------------------- */
.featured-title {
    padding: var(--space-xl) 0;
    background: var(--color-bg-alt);
}

.section-label {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.featured-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    align-items: center;
}

@media (min-width: 992px) {
    .featured-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-xl);
    }
}

.book-cover-container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.book-cover {
    max-width: 100%;
    width: 400px;
    height: auto;
    box-shadow: 
        0 25px 50px -12px rgba(26, 25, 23, 0.15),
        0 12px 24px -8px rgba(26, 25, 23, 0.1);
    transition: transform var(--transition-medium), box-shadow var(--transition-medium);
}

.book-cover:hover {
    transform: translateY(-8px);
    box-shadow: 
        0 35px 60px -15px rgba(26, 25, 23, 0.2),
        0 20px 40px -12px rgba(26, 25, 23, 0.12);
}

.book-details {
    max-width: 500px;
}

.book-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 400;
    line-height: 1.2;
    margin: 0 0 var(--space-xs) 0;
}

.book-subtitle {
    font-family: var(--font-serif);
    font-size: 1.125rem;
    font-style: italic;
    color: var(--color-text-secondary);
    margin: 0 0 var(--space-md) 0;
}

.book-author {
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin: 0 0 var(--space-md) 0;
}

.book-description {
    font-family: var(--font-serif);
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin: 0 0 var(--space-md) 0;
    line-height: 1.8;
}

.book-meta {
    display: flex;
    gap: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--color-border);
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
    margin: 0;
}

.book-meta div {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.book-meta dt {
    font-weight: 500;
    color: var(--color-text-secondary);
}

.book-meta dd {
    margin: 0;
}

/* Buttons */
.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    background: var(--color-text);
    color: var(--color-bg);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    text-decoration: none;
    padding: 1rem 2rem;
    border: none;
    cursor: pointer;
    transition: background var(--transition-fast), transform var(--transition-fast);
    margin-top: var(--space-md);
}

.btn-primary:hover {
    background: var(--color-accent);
    color: var(--color-text);
    transform: translateY(-2px);
}

.btn-primary svg {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

/* ----------------------------------------
   ABOUT SECTION
   ---------------------------------------- */
.about {
    padding: var(--space-xl) 0;
}

.about-content {
    max-width: 800px;
}

.about-text {
    font-family: var(--font-serif);
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
    line-height: 1.8;
    color: var(--color-text);
    margin: 0 0 var(--space-md) 0;
}

.about-text:last-child {
    margin-bottom: 0;
}

.about-text strong {
    color: var(--color-text);
    font-weight: 500;
}

.highlight {
    position: relative;
    display: inline;
}

.highlight::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 0.35em;
    background: var(--color-accent);
    opacity: 0.4;
    z-index: -1;
}

/* ----------------------------------------
   FOOTER
   ---------------------------------------- */
.site-footer {
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

@media (min-width: 768px) {
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr;
    }
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    height: 28px;
    width: auto;
    margin-bottom: var(--space-sm);
    opacity: 0.8;
}

.footer-tagline {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin: 0;
}

.footer-nav h4 {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    margin: 0 0 var(--space-sm) 0;
}

.footer-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-nav a {
    font-size: 0.875rem;
    color: var(--color-text);
    text-decoration: none;
    transition: color var(--transition-fast);
    display: block;
    padding: 0.25rem 0;
}

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

.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
    padding-top: var(--space-md);
    border-top: 1px solid var(--color-border);
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
}

.footer-bottom p {
    margin: 0;
}

.footer-bottom a {
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ----------------------------------------
   UTILITIES
   ---------------------------------------- */
.container-fluid {
    max-width: 1600px;
    padding-left: var(--space-md);
    padding-right: var(--space-md);
    margin-left: auto;
    margin-right: auto;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ----------------------------------------
   RESPONSIVE ADJUSTMENTS
   ---------------------------------------- */
@media (max-width: 767px) {
    :root {
        --space-lg: 3rem;
        --space-xl: 5rem;
    }

    .nav-panel {
        max-width: 100%;
        padding: var(--space-lg) var(--space-md);
    }

    .book-meta {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .hero-background img {
        left: -20%;
        width: 140%;
    }
}

/* ----------------------------------------
   REDUCED MOTION
   ---------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .hero-background img {
        animation: none;
    }

    .scroll-indicator-line {
        animation: none;
    }
}