/* ============================================================
   Variation C "Schematic" -- Section frame (sheet) chrome
   Every section is treated as a "drawing sheet": a fine drafting
   border, a title block in the upper-left, a sheet code in the
   upper-right, a sheet counter at the bottom.
   ============================================================ */

/* --------------------------------------------------------------------------
   Sheet wrapper -- applied to every section element
   -------------------------------------------------------------------------- */

.sheet {
    position: relative;
    /* Each sheet has a hairline drafting border on all 4 sides */
    border-top: var(--border-drafting);
    /* Bottom border is dropped per-section because adjacent sheets share it */
    padding: clamp(3rem, 6vh, 5rem) 0 clamp(3rem, 6vh, 5rem);
    overflow: hidden;
    background-color: transparent;
}


/* --------------------------------------------------------------------------
   Title block -- upper-left of each sheet
   Format:
     [ SHEET 02 / 11 ]
     CATALOG OVERVIEW
     -- REV 2026.04
   -------------------------------------------------------------------------- */

.sheet__title-block {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-bottom: clamp(2rem, 4vh, 3rem);
    border-left: 2px solid var(--color-accent-2);
    padding-left: clamp(0.75rem, 1.5vw, 1.25rem);
    max-width: 56ch;
}

.sheet__title-block-code {
    font-family: var(--font-mono);
    font-size: var(--text-sheet-code);
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--color-accent-2);
}

.sheet__title-block-name {
    font-family: var(--font-heading);
    font-size: var(--text-section-c);
    font-weight: 200;
    letter-spacing: var(--tracking-tight);
    line-height: 1.1;
    color: var(--text-primary);
    text-wrap: balance;
    margin: 0;
}

.sheet__title-block-rev {
    font-family: var(--font-mono);
    font-size: var(--text-dim-label);
    font-weight: 400;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--gray-500);
    margin-top: 6px;
}


/* --------------------------------------------------------------------------
   Sheet code badge -- upper-right of each sheet
   Mirror of the title block code, anchored to the right edge.
   -------------------------------------------------------------------------- */

.sheet__code-badge {
    position: absolute;
    top: clamp(1.25rem, 2.5vh, 1.75rem);
    right: clamp(1rem, 2vw, 1.5rem);
    z-index: 2;
    display: inline-flex;
    align-items: center;
    gap: 0.5em;
    font-family: var(--font-mono);
    font-size: var(--text-sheet-code);
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--color-accent-2);
    padding: 4px 10px;
    border: 1px solid var(--color-accent-2-soft);
    background-color: rgba(10, 22, 40, 0.6);
    pointer-events: none;
}


/* --------------------------------------------------------------------------
   Sheet footer -- markings at the bottom-left of each sheet
   Format: SHEET 02 / 11 -- DRAWN 2026
   -------------------------------------------------------------------------- */

.sheet__footer {
    margin-top: clamp(2rem, 4vh, 3rem);
    padding-top: clamp(1rem, 2vh, 1.5rem);
    border-top: 1px solid var(--color-drafting-border);
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: var(--space-md);
    flex-wrap: wrap;
    font-family: var(--font-mono);
    font-size: var(--text-dim-label);
    font-weight: 400;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--gray-500);
}

.sheet__footer-left {
    display: inline-flex;
    align-items: baseline;
    gap: 0.75em;
}


/* --------------------------------------------------------------------------
   Persistent sheet-counter wayfinder
   Floats in the upper-right corner during scroll, updates as the visitor
   passes between section boundaries (managed in main.js).
   -------------------------------------------------------------------------- */

.sheet-counter {
    position: fixed;
    top: clamp(5rem, 8vh, 6rem);
    right: clamp(1.5rem, 3vw, 2.5rem);
    z-index: 50;
    display: inline-flex;
    align-items: center;
    gap: 0.5em;
    padding: 6px 12px;
    font-family: var(--font-mono);
    font-size: var(--text-sheet-code);
    font-weight: 500;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--color-accent-2);
    background-color: rgba(10, 22, 40, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--color-accent-2-soft);
    pointer-events: none;
    opacity: 0;
    transform: translateY(-4px);
    transition: opacity 400ms var(--ease-out),
                transform 400ms var(--ease-out);
}

.sheet-counter.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.sheet-counter__current {
    color: var(--text-primary);
}

.sheet-counter__divider {
    color: var(--color-accent-2-soft);
}

.sheet-counter__total {
    color: var(--gray-400);
}


/* --------------------------------------------------------------------------
   Annotation lines -- small SVG decorations connecting elements to labels
   Used inline in sections for callouts.
   -------------------------------------------------------------------------- */

.annotation-line {
    color: var(--color-accent-2-line);
}

.annotation-label {
    font-family: var(--font-mono);
    font-size: var(--text-dim-label);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--color-accent-2);
}


/* --------------------------------------------------------------------------
   Responsive -- on small viewports, drop the sheet-code badge and counter
   -------------------------------------------------------------------------- */

@media (max-width: 768px) {
    .sheet-counter {
        display: none;
    }

    .sheet__code-badge {
        font-size: 0.625rem;
        padding: 3px 8px;
    }

    .sheet__title-block {
        padding-left: 0.875rem;
    }

    .sheet__footer {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5em;
    }
}