/* ==========================================================================
   CYS401 slide-breakdown shared design layer
   Loaded AFTER each page's own <style>. Provides:
     · neutral theme tokens for light + dark (--bd-*)
     · floating control rail (theme toggle, top, print)
     · reading-progress bar
     · typography, table, code, focus, scrollbar and print polish
   Each page keeps its own accent palette and layout.
   ========================================================================== */

:root {
    --bd-bg: #f4f6fa;
    --bd-bg-alt: #eaeef6;
    --bd-surface: #ffffff;
    --bd-surface-2: #f7f9fc;
    --bd-border: #dbe2ee;
    --bd-border-soft: rgba(20, 32, 55, .08);
    --bd-text: #131a26;
    --bd-text-dim: #5a6779;
    --bd-shadow: 0 1px 2px rgba(15, 25, 45, .05), 0 10px 30px rgba(15, 25, 45, .07);
    --bd-ring: rgba(56, 132, 232, .45);
    --bd-radius: 14px;
}

html[data-theme="dark"] {
    --bd-bg: #080c14;
    --bd-bg-alt: #0c121d;
    --bd-surface: #111926;
    --bd-surface-2: #0d141f;
    --bd-border: #22304a;
    --bd-border-soft: rgba(190, 214, 255, .10);
    --bd-text: #e6ecf6;
    --bd-text-dim: #93a3bb;
    --bd-shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 14px 36px rgba(0, 0, 0, .45);
    --bd-ring: rgba(120, 190, 255, .5);
}

/* ---------- typography polish (inherits each page's own fonts) ---------- */
html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: .001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: .001ms !important;
    }
}

body {
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
    text-wrap: balance;
}

p,
li {
    text-wrap: pretty;
}

/* ---------- readable tables everywhere ---------- */
.bd-table-scroll {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--bd-radius);
    scrollbar-width: thin;
}

.bd-table-scroll>table {
    min-width: 460px;
}

/* ---------- focus + selection ---------- */
a:focus-visible,
button:focus-visible,
select:focus-visible,
input:focus-visible,
[tabindex]:focus-visible,
summary:focus-visible {
    outline: 2px solid var(--bd-ring);
    outline-offset: 2px;
    border-radius: 6px;
}

/* ---------- scrollbar ---------- */
* {
    scrollbar-color: var(--bd-border) transparent;
}

::-webkit-scrollbar {
    width: 11px;
    height: 11px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--bd-border);
    border-radius: 999px;
    border: 3px solid transparent;
    background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--bd-text-dim);
    background-clip: content-box;
}

/* ---------- reading progress ---------- */
.bd-progress {
    position: fixed;
    inset: 0 0 auto 0;
    height: 3px;
    z-index: 2147483000;
    background: transparent;
    pointer-events: none;
}

.bd-progress>i {
    display: block;
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, #3b82f6, #8b5cf6, #ec4899);
    transition: width .1s linear;
}

/* ---------- floating control rail ---------- */
.bd-rail {
    position: fixed;
    right: 18px;
    bottom: 18px;
    z-index: 2147483000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    font-family: ui-monospace, 'JetBrains Mono', SFMono-Regular, Menlo, monospace;
}

.bd-rail button {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bd-surface);
    color: var(--bd-text-dim);
    border: 1px solid var(--bd-border);
    box-shadow: var(--bd-shadow);
    transition: transform .18s ease, color .18s ease, border-color .18s ease, opacity .25s ease;
    padding: 0;
}

.bd-rail button:hover {
    transform: translateY(-2px);
    color: var(--bd-text);
    border-color: var(--bd-ring);
}

.bd-rail button:active {
    transform: translateY(0);
}

.bd-rail button svg {
    width: 18px;
    height: 18px;
    stroke-width: 2;
}

.bd-rail button.bd-hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateY(8px);
}

.bd-rail .bd-tip {
    position: absolute;
    right: 52px;
    white-space: nowrap;
    background: var(--bd-text);
    color: var(--bd-bg);
    font-size: 11px;
    padding: 5px 9px;
    border-radius: 7px;
    opacity: 0;
    pointer-events: none;
    transition: opacity .16s ease;
}

.bd-rail button:hover .bd-tip {
    opacity: .95;
}

@media (max-width: 600px) {
    .bd-rail {
        right: 12px;
        bottom: 12px;
    }

    .bd-rail button {
        width: 38px;
        height: 38px;
    }

    .bd-rail .bd-tip {
        display: none;
    }
}

/* ---------- theme transition (skipped on first paint) ---------- */
html.bd-ready body,
html.bd-ready body * {
    transition: background-color .28s ease, border-color .28s ease, color .28s ease;
}

html.bd-ready body *:hover {
    transition-duration: .18s;
}

/* ---------- print ---------- */
@media print {

    .bd-rail,
    .bd-progress {
        display: none !important;
    }

    body {
        background: #fff !important;
        color: #000 !important;
    }

    * {
        box-shadow: none !important;
    }

    a[href^="http"]::after {
        content: " (" attr(href) ")";
        font-size: 10px;
        color: #555;
    }
}