/* ============================================================
   transactology.com — Swiss Typographic Ledger
   Palette: Cool-grays with ledger precision
   Typography: Space Grotesk + Inter
   ============================================================ */

:root {
    --bg-primary: #FAFAF8;
    --bg-secondary: #F0EDE8;
    --surface: #FFFFFF;
    --text-primary: #1A1A1A;
    --text-secondary: #3A3A3A;
    --text-tertiary: #8A8A8A;
    --rule: #D4D0C8;
    --rule-strong: #2A2A2A;
    --accent: #2A5A8A;
    --highlight: #E8F0F8;

    --container-max: 1200px;
    --container-pad: 40px;
    --col-gap: 20px;

    --font-display: 'Space Grotesk', 'Inter', system-ui, sans-serif;
    --font-body: 'Inter', system-ui, sans-serif;
    --font-mono: 'Space Grotesk', 'Inter', monospace;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.7;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
    position: relative;
}

/* Graph paper grid background */
.grid-bg {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    background-image:
        repeating-linear-gradient(
            to right,
            rgba(26, 26, 26, 0.06) 0,
            rgba(26, 26, 26, 0.06) 1px,
            transparent 1px,
            transparent 80px
        ),
        repeating-linear-gradient(
            to bottom,
            rgba(26, 26, 26, 0.06) 0,
            rgba(26, 26, 26, 0.06) 1px,
            transparent 1px,
            transparent 80px
        );
    opacity: 0.5;
}

.container {
    position: relative;
    z-index: 1;
}

/* 12-column grid */
.grid-12 {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 0 var(--col-gap);
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-pad);
    position: relative;
}

/* ============================================================
   TOP NAVIGATION
   ============================================================ */
.topnav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(250, 250, 248, 0.92);
    backdrop-filter: saturate(140%) blur(8px);
    -webkit-backdrop-filter: saturate(140%) blur(8px);
    border-bottom: 1px solid var(--rule);
}

.topnav-inner {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 16px var(--container-pad);
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 32px;
}

.topnav-brand {
    display: flex;
    align-items: baseline;
    gap: 10px;
}

.brand-mark {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 18px;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.brand-name {
    font-family: var(--font-body);
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 400;
    letter-spacing: -0.01em;
}

.topnav-list {
    list-style: none;
    display: flex;
    gap: 28px;
}

.nav-link {
    font-family: var(--font-display);
    font-size: 11px;
    font-weight: 400;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-decoration: none;
    padding-bottom: 4px;
    border-bottom: 2px solid transparent;
    transition: color 0.25s ease, border-color 0.25s ease;
}

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

.nav-link.active {
    color: var(--text-primary);
    border-bottom-color: var(--text-primary);
}

.topnav-meta {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

.meta-label {
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    line-height: 1.3;
}

.meta-divider {
    color: var(--rule);
    font-size: 11px;
    line-height: 1.3;
}

/* ============================================================
   GENERIC SECTION HELPERS
   ============================================================ */
.block {
    padding: 120px 0;
    position: relative;
}

.section-header {
    grid-column: 1 / span 12;
    margin-bottom: 64px;
}

.section-title {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: clamp(36px, 4.5vw, 56px);
    line-height: 1.05;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin: 16px 0 28px;
}

.section-deck {
    margin-top: 28px;
    max-width: 60ch;
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.7;
}

.rule-wrap {
    width: 100%;
    overflow: hidden;
}

.rule-svg {
    width: 100%;
    height: 2px;
    display: block;
}

.draw-line {
    stroke-dasharray: 1200;
    stroke-dashoffset: 1200;
    transition: stroke-dashoffset 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.in-view .draw-line {
    stroke-dashoffset: 0;
}

/* ============================================================
   HEADER BLOCK
   ============================================================ */
.block-header {
    min-height: 100vh;
    padding-top: 180px;
    padding-bottom: 80px;
    display: flex;
    align-items: center;
}

.block-header .grid-12 {
    width: 100%;
    align-content: center;
}

.header-meta {
    grid-column: 1 / span 12;
    display: flex;
    align-items: baseline;
    gap: 14px;
    margin-bottom: 36px;
}

.display-title {
    grid-column: 1 / span 12;
    font-family: var(--font-display);
    font-weight: 500;
    font-size: clamp(56px, 10vw, 144px);
    line-height: 0.96;
    letter-spacing: -0.035em;
    color: var(--text-primary);
    margin-bottom: 56px;
}

.title-line {
    display: block;
}

.title-line-alt {
    color: var(--text-tertiary);
    font-weight: 400;
}

.block-header .rule-wrap {
    grid-column: 1 / span 12;
    margin-bottom: 32px;
}

.header-subtitle {
    grid-column: 1 / span 6;
    margin-bottom: 64px;
}

.subtitle-caps {
    font-family: var(--font-body);
    font-size: 17px;
    line-height: 1.55;
    color: var(--text-secondary);
    max-width: 60ch;
}

.header-figures {
    grid-column: 7 / span 6;
    grid-row: 4;
    align-self: end;
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 64px;
}

.figure-row {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding: 8px 0;
    border-bottom: 1px solid var(--rule);
}

.figure-row:first-child {
    border-top: 1px solid var(--rule);
}

.figure-label {
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    flex-shrink: 0;
}

.figure-leader {
    flex: 1;
    border-bottom: 1px dotted var(--rule);
    transform: translateY(-4px);
    height: 0;
}

.figure-value {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 20px;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
    flex-shrink: 0;
}

.header-foot {
    grid-column: 1 / span 12;
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 32px;
}

.scroll-tick {
    width: 1px;
    height: 28px;
    background: var(--text-primary);
    display: inline-block;
    animation: scrollTick 1.6s ease-in-out infinite;
    transform-origin: top;
}

@keyframes scrollTick {
    0%, 100% { transform: scaleY(0.4); opacity: 0.4; }
    50% { transform: scaleY(1); opacity: 1; }
}

/* ============================================================
   DEFINITION SECTION
   ============================================================ */
.block-definition {
    background: var(--bg-primary);
}

.vertical-label {
    grid-column: 1 / span 1;
    position: sticky;
    top: 120px;
    align-self: start;
    height: 320px;
}

.vertical-label span {
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.25em;
    text-transform: uppercase;
    white-space: nowrap;
    display: inline-block;
}

.definition-body {
    grid-column: 3 / span 8;
}

.definition-body p {
    margin-bottom: 24px;
    color: var(--text-secondary);
    max-width: 64ch;
}

.lede {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: 24px;
    line-height: 1.4;
    color: var(--text-primary);
    margin-bottom: 36px !important;
    letter-spacing: -0.01em;
}

.lede em {
    font-style: italic;
    color: var(--accent);
}

.amount-divider {
    margin: 36px 0;
}

.amount-row {
    display: flex;
    align-items: baseline;
    gap: 14px;
    padding-top: 12px;
}

.amount-key {
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    flex-shrink: 0;
}

.amount-leader {
    flex: 1;
    border-bottom: 1px dotted var(--rule);
    height: 0;
    transform: translateY(-4px);
}

.amount-figure {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 20px;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
    flex-shrink: 0;
}

.pull-quote {
    margin: 56px 0 0;
    padding: 36px 0 36px 32px;
    border-left: 1px solid var(--rule-strong);
    position: relative;
}

.pull-quote .quote-mark {
    font-family: var(--font-display);
    font-size: 56px;
    line-height: 1;
    color: var(--accent);
    position: absolute;
    left: 16px;
    top: 12px;
}

.pull-quote p {
    font-family: var(--font-display);
    font-size: 22px;
    line-height: 1.4;
    color: var(--text-primary);
    margin-bottom: 16px !important;
    padding-left: 32px;
    letter-spacing: -0.01em;
    max-width: none !important;
}

.quote-attr {
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    padding-left: 32px;
    display: inline-block;
}

/* ============================================================
   FRAMEWORK GRID
   ============================================================ */
.block-framework {
    background: var(--bg-primary);
    border-top: 1px solid var(--rule);
}

.framework-body {
    grid-column: 3 / span 10;
}

.framework-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    border-top: 1px solid var(--rule);
    border-left: 1px solid var(--rule);
    margin-top: 24px;
}

.cell {
    border-right: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
    padding: 28px 24px;
    background: var(--bg-primary);
    position: relative;
    transition: background 0.3s ease;
    min-height: 220px;
    display: flex;
    flex-direction: column;
}

.cell:hover {
    background: var(--highlight);
}

.cell-num {
    font-family: var(--font-display);
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    margin-bottom: 12px;
    font-variant-numeric: tabular-nums;
}

.cell-title {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 28px;
    color: var(--text-primary);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.cell-body {
    font-size: 14px;
    line-height: 1.55;
    color: var(--text-secondary);
    flex: 1;
}

.cell-tag {
    font-family: var(--font-display);
    font-size: 10px;
    color: var(--accent);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    margin-top: 16px;
    padding-top: 12px;
    border-top: 1px dotted var(--rule);
}

.flow-arrows {
    margin-top: 64px;
    width: 100%;
    height: 120px;
}

.flow-arrows svg {
    width: 100%;
    height: 100%;
}

.flow-path {
    stroke-dasharray: 400;
    stroke-dashoffset: 400;
    transition: stroke-dashoffset 1.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.in-view .flow-path {
    stroke-dashoffset: 0;
}

.flow-path:nth-child(2) { transition-delay: 0.15s; }
.flow-path:nth-child(3) { transition-delay: 0.30s; }
.flow-path:nth-child(4) { transition-delay: 0.45s; }

/* ============================================================
   LEDGER FOOTER
   ============================================================ */
.block-ledger {
    background: var(--bg-secondary);
    border-top: 1px solid var(--rule);
}

.ledger-body {
    grid-column: 3 / span 10;
}

.ledger-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 24px;
    font-variant-numeric: tabular-nums;
}

.ledger-table thead th {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: 11px;
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-align: left;
    padding: 14px 12px;
    border-bottom: 1px solid var(--rule-strong);
}

.ledger-table .col-debit,
.ledger-table .col-credit,
.ledger-table .num {
    text-align: right;
}

.ledger-table tbody td {
    font-family: var(--font-body);
    font-size: 15px;
    color: var(--text-secondary);
    padding: 14px 12px;
    border-bottom: 1px dotted var(--rule);
}

.ledger-table tbody tr:hover {
    background: var(--highlight);
}

.ledger-table .num {
    font-family: var(--font-display);
    font-weight: 500;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}

.ledger-table tfoot .subtotal-row td {
    font-family: var(--font-display);
    font-size: 13px;
    color: var(--text-primary);
    padding: 18px 12px 10px;
    border-top: 1px solid var(--rule-strong);
    border-bottom: none;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.15em;
}

.ledger-table tfoot .subtotal-row .num {
    font-size: 16px;
}

.ledger-table tfoot .total-row td {
    font-family: var(--font-display);
    font-size: 13px;
    color: var(--text-primary);
    padding: 14px 12px;
    border-top: 1px solid var(--rule-strong);
    border-bottom: 3px double var(--rule-strong);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-weight: 500;
}

.ledger-table tfoot .total-row .num {
    font-size: 22px;
    font-weight: 600;
    color: var(--text-primary);
}

.ledger-notes {
    margin-top: 56px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.note-block .meta-label {
    display: block;
    margin-bottom: 8px;
}

.note-block p {
    font-size: 13px;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* ============================================================
   COLOPHON / FOOTER
   ============================================================ */
.colophon {
    padding: 96px 0 48px;
    border-top: 1px solid var(--rule);
    background: var(--bg-primary);
}

.colophon-left {
    grid-column: 1 / span 6;
}

.colophon-left .brand-mark {
    font-size: 48px;
    margin-bottom: 16px;
    display: block;
}

.colophon-text {
    font-size: 13px;
    color: var(--text-secondary);
    max-width: 48ch;
    line-height: 1.6;
}

.colophon-right {
    grid-column: 8 / span 5;
}

.colophon-meta {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 8px 24px;
    font-family: var(--font-display);
    font-size: 12px;
}

.colophon-meta dt {
    color: var(--text-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    font-size: 10px;
    align-self: center;
}

.colophon-meta dd {
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}

.colophon-rule {
    grid-column: 1 / span 12;
    margin: 48px 0 24px;
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.rule-thick {
    height: 2px;
    background: var(--rule-strong);
    display: block;
}

.rule-thin {
    height: 1px;
    background: var(--rule-strong);
    display: block;
}

.colophon-foot {
    grid-column: 1 / span 12;
    display: flex;
    justify-content: space-between;
    align-items: baseline;
}

/* ============================================================
   RESPONSIVE — collapse to 4-column grid
   ============================================================ */
@media (max-width: 768px) {
    :root {
        --container-pad: 24px;
    }

    .grid-12 {
        grid-template-columns: repeat(4, 1fr);
    }

    .topnav-inner {
        grid-template-columns: 1fr auto;
        padding: 12px 24px;
    }

    .topnav-meta {
        display: none;
    }

    .topnav-list {
        gap: 16px;
    }

    .nav-link {
        font-size: 10px;
        letter-spacing: 0.12em;
    }

    .block {
        padding: 80px 0;
    }

    .block-header {
        padding-top: 140px;
    }

    .display-title {
        font-size: clamp(40px, 12vw, 80px);
    }

    .header-subtitle {
        grid-column: 1 / span 4;
    }

    .header-figures {
        grid-column: 1 / span 4;
        grid-row: auto;
    }

    .figure-row {
        flex-wrap: wrap;
    }

    .vertical-label {
        display: none;
    }

    .definition-body,
    .framework-body,
    .ledger-body {
        grid-column: 1 / span 4;
    }

    .framework-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .cell {
        min-height: 200px;
        padding: 24px 20px;
    }

    .ledger-table {
        font-size: 13px;
    }

    .ledger-table thead th,
    .ledger-table tbody td {
        padding: 10px 8px;
    }

    .ledger-table .col-period,
    .ledger-table .col-currency {
        display: none;
    }

    .ledger-notes {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .colophon-left,
    .colophon-right {
        grid-column: 1 / span 4;
    }

    .colophon-right {
        margin-top: 32px;
    }

    .colophon-foot {
        flex-direction: column;
        gap: 8px;
    }
}

/* fade-in for in-view sections */
.block {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.block.in-view,
.block-header {
    opacity: 1;
    transform: translateY(0);
}

.block-header {
    transition: none;
}