/* === RESET & BASE === */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-void: #1a1714;
    --color-dark: #3d3a34;
    --color-leather: #9e8a6e;
    --color-parchment: #f0e8d8;
    --color-cream: #faf7f0;
    --color-moss: #4a7c59;
    --color-sage: #6b8f71;
    --color-ember: #c4643a;

    --font-display: 'Instrument Serif', serif;
    --font-body: 'Karla', sans-serif;
    --font-mono: 'DM Mono', monospace;

    --ease-drift: cubic-bezier(0.23, 1, 0.32, 1);
    --duration-slow: 1.2s;
    --duration-med: 0.8s;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--color-void);
    color: var(--color-parchment);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* === GRAIN OVERLAY === */
.grain-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1000;
    opacity: 0.04;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(250,247,240,0.3) 0.5px, transparent 0.5px),
        radial-gradient(circle at 70% 60%, rgba(250,247,240,0.2) 1px, transparent 1px),
        radial-gradient(circle at 40% 80%, rgba(250,247,240,0.25) 0.7px, transparent 0.7px);
    background-size: 3px 3px, 7px 7px, 5px 5px;
}

/* === PHOSPHOR SCANLINES === */
.phosphor-scanlines {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 999;
    opacity: 0.03;
    background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 2px,
        rgba(107,143,113,0.15) 2px,
        rgba(107,143,113,0.15) 4px
    );
}

/* === NAVIGATION === */
.nav-float {
    position: fixed;
    top: 2rem;
    left: 2rem;
    z-index: 100;
    display: flex;
    align-items: baseline;
    gap: 1rem;
    opacity: 0;
    transform: translateY(-10px);
    animation: fadeIn var(--duration-slow) var(--ease-drift) 0.5s forwards;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-cream);
}

.nav-subtitle {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-leather);
    letter-spacing: 0.05em;
}

/* === SECTIONS === */
.section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 2rem;
    position: relative;
}

.section-inner {
    max-width: 1400px;
    width: 100%;
    padding: 0 4rem;
}

.section-offset-right .section-inner,
.section-offset-right {
    padding-left: 20%;
}

.section-offset-left .section-inner,
.section-offset-left {
    padding-right: 20%;
}

.section-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--color-leather);
    display: block;
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--duration-med) var(--ease-drift), transform var(--duration-med) var(--ease-drift);
}

.section-heading {
    font-family: var(--font-display);
    font-size: clamp(3rem, 9vw, 8rem);
    font-weight: 400;
    letter-spacing: -0.03em;
    line-height: 1.05;
    color: var(--color-cream);
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity var(--duration-slow) var(--ease-drift), transform var(--duration-slow) var(--ease-drift);
}

.section-body {
    font-family: var(--font-body);
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--color-parchment);
    max-width: 520px;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity var(--duration-slow) var(--ease-drift) 0.2s, transform var(--duration-slow) var(--ease-drift) 0.2s;
}

/* Visible state */
.section.is-visible .section-label,
.section.is-visible .section-heading,
.section.is-visible .section-body {
    opacity: 1;
    transform: translateY(0);
}

/* === HERO === */
.section-hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.hero-title {
    font-family: var(--font-display);
    font-weight: 400;
    margin-bottom: 2rem;
}

.title-line {
    display: block;
    font-size: clamp(3.5rem, 12vw, 10rem);
    letter-spacing: -0.03em;
    line-height: 1.05;
    color: var(--color-cream);
    opacity: 0;
    transform: translateY(60px);
    animation: heroReveal var(--duration-slow) var(--ease-drift) 0.3s forwards;
}

.title-jp {
    font-size: clamp(1.5rem, 4vw, 3rem);
    color: var(--color-leather);
    letter-spacing: 0.1em;
    animation-delay: 0.6s;
}

.hero-sub {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-sage);
    letter-spacing: 0.1em;
    opacity: 0;
    animation: fadeIn var(--duration-slow) var(--ease-drift) 1s forwards;
}

/* === KOAN BLOCK === */
.koan-block {
    margin-top: 3rem;
    padding: 2rem;
    border-left: 2px solid var(--color-ember);
    position: relative;
    opacity: 0;
    transform: translateX(-20px);
    transition: opacity var(--duration-slow) var(--ease-drift) 0.4s, transform var(--duration-slow) var(--ease-drift) 0.4s;
}

.section.is-visible .koan-block {
    opacity: 1;
    transform: translateX(0);
}

.koan-mark {
    font-family: var(--font-display);
    font-size: 4rem;
    color: var(--color-ember);
    position: absolute;
    top: -0.5rem;
    left: 1rem;
    opacity: 0.4;
}

.koan-text {
    font-family: var(--font-display);
    font-size: 1.4rem;
    line-height: 1.6;
    color: var(--color-parchment);
    font-style: italic;
}

/* === MATERIAL GRID === */
.material-grid {
    display: flex;
    gap: 1.5rem;
    margin-top: 3rem;
    opacity: 0;
    transition: opacity var(--duration-slow) var(--ease-drift) 0.4s;
}

.section.is-visible .material-grid {
    opacity: 1;
}

.material-swatch {
    width: 120px;
    height: 120px;
    border-radius: 4px;
}

.swatch-warm {
    background: var(--color-leather);
    background-image:
        radial-gradient(circle at 30% 40%, rgba(26,23,20,0.2) 1px, transparent 1px),
        radial-gradient(circle at 70% 60%, rgba(26,23,20,0.15) 0.8px, transparent 0.8px);
    background-size: 4px 4px, 6px 6px;
}

.swatch-grain {
    background: var(--color-dark);
    background-image:
        radial-gradient(circle at 50% 50%, rgba(158,138,110,0.1) 1px, transparent 1px);
    background-size: 3px 3px;
}

.swatch-cold {
    background: var(--color-void);
    border: 1px solid var(--color-sage);
    background-image: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 3px,
        rgba(107,143,113,0.08) 3px,
        rgba(107,143,113,0.08) 4px
    );
}

/* === KINETIC DEMO === */
.kinetic-demo {
    display: flex;
    gap: 3rem;
    margin-top: 3rem;
    opacity: 0;
    transition: opacity var(--duration-slow) var(--ease-drift) 0.4s;
}

.section.is-visible .kinetic-demo {
    opacity: 1;
}

.kinetic-word {
    font-family: var(--font-display);
    font-size: 2.5rem;
    color: var(--color-sage);
    display: inline-block;
}

.kinetic-word[data-kinetic="drift"] {
    animation: drift 4s ease-in-out infinite;
}

.kinetic-word[data-kinetic="settle"] {
    animation: settle 3s var(--ease-drift) infinite;
}

.kinetic-word[data-kinetic="breathe"] {
    animation: breathe 5s ease-in-out infinite;
}

/* === PALETTE === */
.palette-row {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 2rem;
    opacity: 0;
    transition: opacity var(--duration-slow) var(--ease-drift) 0.3s;
}

.section.is-visible .palette-row {
    opacity: 1;
}

.palette-chip {
    width: 80px;
    height: 80px;
    border-radius: 4px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 0.4rem;
    position: relative;
}

.palette-chip span {
    font-family: var(--font-mono);
    font-size: 0.55rem;
    color: var(--color-cream);
    opacity: 0.7;
    text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}

/* === END SECTION === */
.section-end {
    text-align: center;
}

.end-title {
    font-family: var(--font-display);
    font-size: clamp(4rem, 15vw, 12rem);
    color: var(--color-cream);
    opacity: 0.15;
    margin-bottom: 1rem;
}

.end-sub {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-parchment);
    font-style: italic;
    margin-bottom: 2rem;
}

.end-mono {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-leather);
    letter-spacing: 0.1em;
}

/* === ANIMATIONS === */
@keyframes heroReveal {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes drift {
    0%, 100% { transform: translateX(0) translateY(0); }
    25% { transform: translateX(8px) translateY(-3px); }
    50% { transform: translateX(-5px) translateY(2px); }
    75% { transform: translateX(3px) translateY(-1px); }
}

@keyframes settle {
    0% { transform: translateY(-8px); opacity: 0.6; }
    60% { transform: translateY(2px); opacity: 1; }
    100% { transform: translateY(0); opacity: 1; }
}

@keyframes breathe {
    0%, 100% { transform: scale(1); opacity: 0.8; }
    50% { transform: scale(1.05); opacity: 1; }
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
    .section-offset-right,
    .section-offset-left {
        padding-left: 2rem;
        padding-right: 2rem;
    }

    .section-inner {
        padding: 0 1rem;
    }

    .kinetic-demo {
        flex-direction: column;
        gap: 1.5rem;
    }

    .material-grid {
        flex-wrap: wrap;
    }

    .palette-row {
        gap: 0.5rem;
    }

    .palette-chip {
        width: 60px;
        height: 60px;
    }
}