/* ============================================================
   kaguya.bid — Zen-Contemplative Circuit Aesthetics
   Palette: sunset-warm against deep obsidian
   Typography: Fraunces (variable) + Syne (variable) + Space Mono
   ============================================================ */

/* CSS Custom Properties */
@property --glow-intensity {
    syntax: '<number>';
    inherits: true;
    initial-value: 1;
}

@property --glow-spread {
    syntax: '<length>';
    inherits: true;
    initial-value: 24px;
}

:root {
    /* Color palette — full set (pure black/white present as palette anchors, never used directly) */
    --pure-black:   #000000; /* palette anchor only — use --void instead */
    --pure-white:   #FFFFFF; /* palette anchor only — use --cream instead */
    --void:         #0D0D0F;
    --deep-amber:   #1A1610;
    --warm-brown:   #2A1F14;
    --coral:        #E8754A;
    --amber:        #F2A96B;
    --sienna:       #C4613A;
    --cream:        #F7EDD8;
    --muted-amber:  #8B7355;

    /* Glow tokens */
    --glow-coral: 0 0 8px #E8754A40, 0 0 24px #E8754A20, 0 0 60px #E8754A10;
    --glow-amber: 0 0 8px #F2A96B30, 0 0 20px #F2A96B15;

    /* Spacing — base-8 scale */
    --sp-1:  8px;
    --sp-2:  16px;
    --sp-3:  24px;
    --sp-4:  32px;
    --sp-5:  40px;
    --sp-8:  64px;
    --sp-10: 80px;
    --sp-16: 128px;

    /* Typography — fluid scale */
    --fs-display: clamp(3.5rem, 8vw + 1rem, 9rem);
    --fs-h1:      clamp(2rem, 4vw + 0.5rem, 4.5rem);
    --fs-h2:      clamp(1.25rem, 2.5vw + 0.25rem, 2.25rem);
    --fs-body:    clamp(0.9rem, 1vw + 0.5rem, 1.125rem);
    --fs-mono:    12px;
    --fs-label:   11px;

    /* Grid */
    --max-width: 1200px;
    --gutter:    24px;

    /* Easing */
    --ease-water: cubic-bezier(0.23, 1, 0.32, 1);

    /* Animation durations */
    --dur-micro:    300ms;
    --dur-entrance: 1200ms;
    --dur-border:   400ms;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--void);
    color: var(--cream);
    font-family: 'Syne', system-ui, sans-serif;
    font-variation-settings: 'wght' 400;
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================================
   Dot Grid Background Overlay
   ============================================================ */
#dot-grid-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    background-image: radial-gradient(circle, #F7EDD808 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 1;
}

/* ============================================================
   Navigation
   ============================================================ */
#main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--sp-2) var(--sp-3);
    border-bottom: 1px solid #E8754A4D;
    background: transparent;
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-link {
    font-family: 'Space Mono', monospace;
    font-size: var(--fs-label);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted-amber);
    text-decoration: none;
    transition: color var(--dur-micro) var(--ease-water);
}

.nav-link:hover {
    color: var(--cream);
}

/* ============================================================
   Section 1: Hero
   ============================================================ */
.section-hero {
    position: relative;
    z-index: 1;
    width: 100%;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--sp-4);
}

.mandala-container {
    width: min(70vh, 600px);
    height: min(70vh, 600px);
    position: relative;
    transition: box-shadow var(--dur-micro) var(--ease-water);
}

.mandala-svg {
    width: 100%;
    height: 100%;
    animation: mandala-rotate 200s linear infinite;
    filter: drop-shadow(0 0 24px #E8754A30) drop-shadow(0 0 60px #E8754A15);
}

@keyframes mandala-rotate {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

.hero-domain {
    font-family: 'Fraunces', serif;
    font-variation-settings: 'wght' 300, 'opsz' 12;
    font-size: 18px;
    letter-spacing: 0.4em;
    color: var(--cream);
    text-transform: lowercase;
    opacity: 0;
    animation: domain-fadein 1200ms var(--ease-water) 2000ms forwards;
}

@keyframes domain-fadein {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================================
   Shared Block Styles
   ============================================================ */
.block-observe {
    position: relative;
}

/* Corner bracket accents */
.block-corner-tl,
.block-corner-br {
    position: absolute;
    width: 20px;
    height: 20px;
    pointer-events: none;
}

.block-corner-tl {
    top: 0;
    left: 0;
    border-top: 1px solid #E8754A4D;
    border-left: 1px solid #E8754A4D;
}

.block-corner-br {
    bottom: 0;
    right: 0;
    border-bottom: 1px solid #E8754A4D;
    border-right: 1px solid #E8754A4D;
}

/* Border-trace hover: SVG overlay via clip-path / outline */
.block-wide,
.block-accent,
.block-third {
    position: relative;
    padding: var(--sp-5);
    border: 1px solid transparent;
    border-radius: 0;
    transition: border-color var(--dur-micro) var(--ease-water);
    background: transparent;
}

/* Border-trace animation — clip-path clockwise from top-left */
.block-wide::before,
.block-accent::before,
.block-third::before {
    content: '';
    position: absolute;
    inset: -1px;
    border: 1px solid var(--coral);
    pointer-events: none;
    clip-path: inset(0 100% 100% 0);
    transition: clip-path var(--dur-border) var(--ease-water);
    z-index: 2;
}

.block-wide:hover::before,
.block-accent:hover::before,
.block-third:hover::before {
    clip-path: inset(0 0% 0% 0);
}

/* Entrance animation */
.block-wide,
.block-accent,
.block-third {
    opacity: 0;
    transform: translateY(24px);
    transition:
        opacity var(--dur-entrance) var(--ease-water),
        transform var(--dur-entrance) var(--ease-water),
        border-color var(--dur-micro) var(--ease-water);
}

.block-wide.is-visible,
.block-accent.is-visible,
.block-third.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================================
   Typography
   ============================================================ */
.heading-display {
    font-family: 'Fraunces', serif;
    font-variation-settings: 'wght' 300, 'opsz' 144;
    font-size: var(--fs-display);
    line-height: 0.95;
    color: var(--coral);
    letter-spacing: -0.02em;
    margin-bottom: var(--sp-4);
    text-shadow: var(--glow-coral);
}

.heading-h2 {
    font-family: 'Fraunces', serif;
    font-variation-settings: 'wght' 400, 'opsz' 72;
    font-size: var(--fs-h1);
    line-height: 1.05;
    color: var(--coral);
    letter-spacing: -0.01em;
    margin-bottom: var(--sp-3);
}

.body-text {
    font-family: 'Syne', sans-serif;
    font-variation-settings: 'wght' 400;
    font-size: var(--fs-body);
    color: var(--cream);
    line-height: 1.75;
    max-width: 60ch;
    margin-bottom: var(--sp-3);
}

.block-label {
    display: block;
    font-family: 'Space Mono', monospace;
    font-size: var(--fs-mono);
    letter-spacing: 0.08em;
    color: var(--muted-amber);
    margin-bottom: var(--sp-3);
}

.accent-text {
    font-family: 'Syne', sans-serif;
    font-variation-settings: 'wght' 400;
    font-size: var(--fs-body);
    color: var(--muted-amber);
    line-height: 1.6;
    margin-top: var(--sp-3);
}

.accent-glyph {
    font-family: serif;
    font-size: clamp(6rem, 14vw, 12rem);
    color: var(--coral);
    opacity: 0.5;
    line-height: 1;
    text-shadow: var(--glow-coral);
    display: block;
}

.accent-glyph-large {
    font-family: serif;
    font-size: clamp(8rem, 18vw, 16rem);
    color: var(--amber);
    opacity: 0.4;
    line-height: 1;
    display: block;
    text-shadow: var(--glow-amber);
}

/* Ghost link (no button fills, 1px border) */
.ghost-link {
    display: inline-block;
    margin-top: var(--sp-3);
    padding: var(--sp-2) var(--sp-4);
    font-family: 'Syne', sans-serif;
    font-variation-settings: 'wght' 600;
    font-size: var(--fs-body);
    color: var(--coral);
    text-decoration: none;
    border: 1px solid var(--coral);
    border-radius: 0;
    background: transparent;
    letter-spacing: 0.06em;
    transition:
        color var(--dur-micro) var(--ease-water),
        border-color var(--dur-micro) var(--ease-water),
        box-shadow var(--dur-micro) var(--ease-water);
}

.ghost-link:hover {
    color: var(--cream);
    border-color: var(--cream);
    box-shadow: var(--glow-coral);
}

.link-trace {
    display: inline-block;
    margin-left: var(--sp-1);
    transition: transform var(--dur-micro) var(--ease-water);
}

.ghost-link:hover .link-trace {
    transform: translateX(4px);
}

/* ============================================================
   Section 2: Tier 2 — Wide + Accent
   ============================================================ */
.section-tier2 {
    position: relative;
    z-index: 1;
    padding: var(--sp-16) var(--gutter);
}

.tier2-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 8fr 4fr;
    gap: var(--sp-8);
    align-items: start;
}

.block-wide {
    grid-column: 1;
    padding: var(--sp-5);
}

.block-accent {
    grid-column: 2;
    padding: var(--sp-5);
    background: var(--deep-amber);
    margin-top: var(--sp-5);
}

/* ============================================================
   Circuit Trace Dividers
   ============================================================ */
.circuit-divider {
    position: relative;
    z-index: 1;
    margin: var(--sp-10) 0;
    opacity: 0;
    transition: opacity 800ms var(--ease-water);
}

.circuit-divider.is-visible {
    opacity: 1;
}

.circuit-trace-svg {
    width: 100%;
    height: 40px;
    display: block;
}

/* ============================================================
   Section 3: Tier 3 — Three Equal Blocks
   ============================================================ */
.section-tier3 {
    position: relative;
    z-index: 1;
    padding: var(--sp-10) var(--gutter);
}

.tier3-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--sp-4);
}

.block-third {
    padding: var(--sp-5);
    background: var(--warm-brown);
}

/* Top border glow pulse — triggered by IntersectionObserver */
.block-third[data-border-top] {
    border-top: 2px solid transparent;
}

.block-third[data-border-top].is-visible {
    border-top-color: var(--coral);
    animation: top-border-glow-pulse 600ms var(--ease-water) forwards;
}

@keyframes top-border-glow-pulse {
    0%   { box-shadow: 0 -2px 0 0 var(--coral); }
    50%  { box-shadow: 0 -2px 16px 0 var(--coral); }
    100% { box-shadow: 0 -2px 4px 0 #E8754A40; }
}

/* ============================================================
   Section 4: Tier 4 — Full-width Circuit Ribbon
   ============================================================ */
.section-tier4 {
    position: relative;
    z-index: 1;
    padding: var(--sp-10) 0;
    width: 100%;
    background: var(--deep-amber);
    border-top: 1px solid #E8754A1A;
    border-bottom: 1px solid #E8754A1A;
    overflow: hidden;
}

.ribbon-svg {
    width: 100%;
    height: 60px;
    display: block;
}

/* ============================================================
   Section 5: Tier 5 — Reversed (4-col accent left, 8-col right)
   ============================================================ */
.section-tier5 {
    position: relative;
    z-index: 1;
    padding: var(--sp-16) var(--gutter);
}

.tier5-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 4fr 8fr;
    gap: var(--sp-8);
    align-items: start;
}

.tier5-inner .block-accent {
    grid-column: 1;
    margin-top: 0;
    background: var(--warm-brown);
}

.tier5-inner .block-wide {
    grid-column: 2;
}

/* ============================================================
   Section 6: Closing
   ============================================================ */
.section-closing {
    position: relative;
    z-index: 1;
    padding: var(--sp-16) var(--gutter);
    background: var(--deep-amber);
    border-top: 1px solid #E8754A26;
    overflow: hidden;
}

.closing-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    min-height: 320px;
}

.closing-watermark {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: serif;
    font-size: clamp(12rem, 30vw, 24rem);
    color: var(--coral);
    opacity: 0.04;
    pointer-events: none;
    line-height: 1;
}

.closing-content {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--sp-3);
}

.closing-label {
    font-family: 'Fraunces', serif;
    font-variation-settings: 'wght' 300, 'opsz' 12;
    font-size: 14px;
    letter-spacing: 0.35em;
    color: var(--cream);
    text-transform: lowercase;
}

.closing-sub {
    font-family: 'Syne', sans-serif;
    font-variation-settings: 'wght' 400;
    font-size: var(--fs-body);
    color: var(--muted-amber);
    letter-spacing: 0.06em;
}

.closing-contact {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--sp-1);
    margin-top: var(--sp-4);
}

.mono-label {
    font-family: 'Space Mono', monospace;
    font-size: var(--fs-mono);
    letter-spacing: 0.08em;
    color: var(--muted-amber);
    text-transform: lowercase;
}

.mono-link {
    font-family: 'Space Mono', monospace;
    font-size: var(--fs-mono);
    letter-spacing: 0.06em;
    padding: var(--sp-1) var(--sp-3);
}

/* ============================================================
   Kanji watermark in philosophy section
   ============================================================ */
.section-tier5 .block-accent {
    position: relative;
    overflow: hidden;
}

/* ============================================================
   Entrance animation states
   ============================================================ */
.circuit-divider,
.section-tier4 {
    opacity: 0;
    transition: opacity 1000ms var(--ease-water);
}

.circuit-divider.is-visible,
.section-tier4.is-visible {
    opacity: 1;
}

/* ============================================================
   Responsive — Tablet
   ============================================================ */
@media (max-width: 900px) {
    .tier2-inner {
        grid-template-columns: 1fr;
        gap: var(--sp-4);
    }

    .block-accent {
        margin-top: 0;
    }

    .tier3-inner {
        grid-template-columns: 1fr 1fr;
    }

    .tier5-inner {
        grid-template-columns: 1fr;
        gap: var(--sp-4);
    }

    .tier5-inner .block-accent {
        grid-column: 1;
    }

    .tier5-inner .block-wide {
        grid-column: 1;
    }
}

/* ============================================================
   Responsive — Mobile
   ============================================================ */
@media (max-width: 600px) {
    .tier3-inner {
        grid-template-columns: 1fr;
    }

    .mandala-container {
        width: min(85vw, 360px);
        height: min(85vw, 360px);
    }

    .nav-inner {
        gap: var(--sp-3);
    }

    .section-tier2,
    .section-tier5 {
        padding: var(--sp-10) var(--sp-3);
    }

    .section-closing {
        padding: var(--sp-10) var(--sp-3);
    }

    .block-wide,
    .block-accent,
    .block-third {
        padding: var(--sp-4);
    }
}

/* ============================================================
   Glow proximity — controlled by JS via CSS custom property
   ============================================================ */
.mandala-svg {
    filter: drop-shadow(0 0 calc(16px * var(--glow-intensity, 1)) #E8754A30)
            drop-shadow(0 0 calc(40px * var(--glow-intensity, 1)) #E8754A15);
    transition: filter 200ms var(--ease-water);
}