/* ===== CSS Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Theme Colors */
    --paper-bg: #F5F0E6;
    --ink-dark: #3A2E23;
    --ink-brown: #854D2C;
    --ink-light: #7A5136;
    --pencil-gray: #9E9386;
    --orange-brown: #A86434;

    /* UI Colors */
    --shadow-light: rgba(58, 46, 35, 0.1);
    --shadow-medium: rgba(58, 46, 35, 0.15);
    --shadow-dark: rgba(58, 46, 35, 0.25);

    /* Typography */
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Consolas', 'Monaco', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--paper-bg);
    color: var(--ink-dark);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* Paper Texture Effect */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='2' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
    opacity: 0.03;
    pointer-events: none;
    z-index: 1;
}

/* ===== Language Switcher ===== */
.language-switcher {
    position: fixed;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    z-index: 1000;
    display: flex;
    gap: var(--spacing-xs);
    background: rgba(245, 240, 230, 0.95);
    backdrop-filter: blur(10px);
    padding: var(--spacing-xs);
    border-radius: 12px;
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
}

.lang-btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    border: none;
    background: transparent;
    color: var(--ink-dark);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 8px;
    transition: all var(--transition-fast);
    font-family: var(--font-main);
}

.lang-btn:hover {
    background: var(--ink-brown);
    color: var(--paper-bg);
    transform: translateY(-2px);
}

.lang-btn.active {
    background: var(--ink-brown);
    color: var(--paper-bg);
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    position: relative;
    z-index: 2;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.paper-texture {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        linear-gradient(135deg, transparent 25%, rgba(133, 77, 44, 0.02) 25%, rgba(133, 77, 44, 0.02) 50%, transparent 50%, transparent 75%, rgba(133, 77, 44, 0.02) 75%),
        linear-gradient(45deg, transparent 25%, rgba(133, 77, 44, 0.02) 25%, rgba(133, 77, 44, 0.02) 50%, transparent 50%, transparent 75%, rgba(133, 77, 44, 0.02) 75%);
    background-size: 60px 60px;
    opacity: 0.3;
    pointer-events: none;
}

.hero-content {
    text-align: center;
    padding: var(--spacing-lg) 0;
}

.hero-icon {
    margin-bottom: var(--spacing-md);
    animation: float 3s ease-in-out infinite;
}

.hero-icon img {
    width: 120px;
    height: 120px;
    filter: drop-shadow(0 10px 30px var(--shadow-medium));
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    color: var(--ink-brown);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
    opacity: 1 !important;
}

.hero-subtitle {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    color: var(--ink-dark);
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    opacity: 1 !important;
}

.hero-description {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--pencil-gray);
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    opacity: 1 !important;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 12px;
    transition: all var(--transition-medium);
    cursor: pointer;
    border: none;
    font-family: var(--font-main);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--ink-brown);
    color: var(--paper-bg);
    box-shadow: 0 4px 20px var(--shadow-medium);
}

.btn-primary:hover {
    background: var(--orange-brown);
    transform: translateY(-3px);
    box-shadow: 0 8px 30px var(--shadow-dark);
}

.btn-secondary {
    background: transparent;
    color: var(--ink-dark);
    border: 2px solid var(--ink-dark);
}

.btn-secondary:hover {
    background: var(--ink-dark);
    color: var(--paper-bg);
    transform: translateY(-3px);
}

.btn svg {
    position: relative;
    z-index: 1;
}

.btn span {
    position: relative;
    z-index: 1;
}

/* ===== Section Styles ===== */
section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--ink-brown);
    text-align: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, transparent, var(--ink-brown), transparent);
    border-radius: 2px;
}

/* ===== Concept Section ===== */
.concept {
    background: linear-gradient(180deg, var(--paper-bg) 0%, rgba(133, 77, 44, 0.03) 100%);
}

.concept-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.concept-item {
    background: rgba(255, 255, 255, 0.5);
    padding: var(--spacing-md);
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
    transition: all var(--transition-medium);
}

.concept-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 40px var(--shadow-medium);
}

.concept-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
    animation: bounce 2s ease-in-out infinite;
}

.concept-item h3 {
    font-size: 1.5rem;
    color: var(--ink-brown);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.concept-item p {
    color: var(--pencil-gray);
    line-height: 1.6;
}

/* ===== Color Palette Section ===== */
.colors {
    background: var(--paper-bg);
}

.color-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.color-card {
    background: rgba(255, 255, 255, 0.5);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
    transition: all var(--transition-medium);
}

.color-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 12px 40px var(--shadow-medium);
}

.color-swatch {
    width: 100%;
    height: 120px;
    border-bottom: 1px solid rgba(133, 77, 44, 0.1);
}

.color-info {
    padding: var(--spacing-sm);
}

.color-info h4 {
    font-size: 1.1rem;
    color: var(--ink-brown);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
}

.color-info code {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--ink-dark);
    background: rgba(133, 77, 44, 0.05);
    padding: var(--spacing-xs);
    border-radius: 6px;
    margin-bottom: var(--spacing-xs);
}

.color-info p {
    font-size: 0.9rem;
    color: var(--pencil-gray);
}

/* ===== Installation Section ===== */
.installation {
    background: linear-gradient(180deg, var(--paper-bg) 0%, rgba(133, 77, 44, 0.03) 100%);
}

.installation-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.method-card {
    background: rgba(255, 255, 255, 0.5);
    padding: var(--spacing-md);
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
    transition: all var(--transition-medium);
}

.method-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px var(--shadow-medium);
}

.method-card h3 {
    font-size: 1.5rem;
    color: var(--ink-brown);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.method-card ol {
    padding-left: var(--spacing-md);
    color: var(--ink-dark);
}

.method-card ol li {
    margin-bottom: var(--spacing-xs);
    line-height: 1.8;
}

.code-block {
    background: rgba(58, 46, 35, 0.05);
    padding: var(--spacing-sm);
    border-radius: 12px;
    border: 1px solid rgba(133, 77, 44, 0.1);
}

.code-block code {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--ink-dark);
    margin-bottom: var(--spacing-xs);
    overflow-x: auto;
}

.code-block code:last-child {
    margin-bottom: 0;
}

/* ===== Fonts Section ===== */
.fonts {
    background: var(--paper-bg);
}

.fonts-intro {
    text-align: center;
    color: var(--pencil-gray);
    margin-bottom: var(--spacing-md);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.code-block-large {
    background: rgba(58, 46, 35, 0.05);
    padding: var(--spacing-md);
    border-radius: 16px;
    margin-bottom: var(--spacing-md);
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
    overflow-x: auto;
}

.code-block-large pre {
    margin: 0;
}

.code-block-large code {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--ink-dark);
    line-height: 1.6;
}

.font-recommendations {
    background: rgba(255, 255, 255, 0.5);
    padding: var(--spacing-md);
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow-light);
    border: 1px solid rgba(133, 77, 44, 0.1);
}

.font-recommendations h3 {
    font-size: 1.5rem;
    color: var(--ink-brown);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.font-recommendations ul {
    list-style: none;
}

.font-recommendations li {
    padding: var(--spacing-xs) 0;
    color: var(--ink-dark);
    border-bottom: 1px solid rgba(133, 77, 44, 0.1);
}

.font-recommendations li:last-child {
    border-bottom: none;
}

.font-recommendations strong {
    color: var(--ink-brown);
}

/* ===== Footer ===== */
.footer {
    background: linear-gradient(180deg, var(--paper-bg) 0%, rgba(133, 77, 44, 0.05) 100%);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    border-top: 1px solid rgba(133, 77, 44, 0.1);
}

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

.footer-links {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-sm);
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--ink-brown);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-fast);
    position: relative;
}

.footer-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--ink-brown);
    transition: width var(--transition-fast);
}

.footer-links a:hover::after {
    width: 100%;
}

.footer-links a:hover {
    color: var(--orange-brown);
}

.footer-copyright {
    color: var(--pencil-gray);
    font-size: 0.9rem;
}

/* ===== Animations ===== */
@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.fade-in {
    animation: slideUp 0.6s ease-out backwards;
}

.fade-in:nth-child(1) { animation-delay: 0s; }
.fade-in:nth-child(2) { animation-delay: 0.1s; }
.fade-in:nth-child(3) { animation-delay: 0.2s; }
.fade-in:nth-child(4) { animation-delay: 0.3s; }
.fade-in:nth-child(5) { animation-delay: 0.4s; }

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Fallback for no-animation preference */
@media (prefers-reduced-motion: reduce) {
    .fade-in {
        animation: none;
        opacity: 1;
        transform: none;
    }
}

.fade-in-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }

    .language-switcher {
        top: var(--spacing-xs);
        right: var(--spacing-xs);
    }

    .hero-icon img {
        width: 80px;
        height: 80px;
    }

    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

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

    .color-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }

    .installation-methods {
        grid-template-columns: 1fr;
    }

    .footer-links {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

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

/* ===== Print Styles ===== */
@media print {
    .language-switcher,
    .hero-cta,
    .paper-texture {
        display: none;
    }

    body::before {
        display: none;
    }

    section {
        page-break-inside: avoid;
    }
}