/* SPDX-License-Identifier: Apache-2.0 */
/* Copyright 2026 cubestudio-dev <cubestudio@qq.com> */
/* Open Cube OS website facade styles - pure CSS, themable (light/dark)
   via CSS custom properties on <html data-theme>, responsive down to
   390px. No frameworks. */

/* ---------- theme variables ---------- */
:root,
html[data-theme="light"] {
    --bg: #f6f8f6;
    --bg-soft: #ecefee;
    --card: #ffffff;
    --text: #1a211c;
    --text-dim: #5a6560;
    --accent: #1f9d55;
    --accent-strong: #17793f;
    --accent-soft: rgba(31, 157, 85, 0.10);
    --border: #e0e5e2;
    --code-bg: #eef1ee;
    --code-text: #24352b;
    --term-bg: #0b0f0c;
    --term-text: #d7e4db;
    --term-green: #46d977;
    --shadow: 0 1px 2px rgba(20, 30, 24, 0.06), 0 8px 24px rgba(20, 30, 24, 0.07);
    --nav-bg: rgba(246, 248, 246, 0.92);
    color-scheme: light;
}
html[data-theme="dark"] {
    --bg: #0b0f0c;
    --bg-soft: #0e1310;
    --card: #121813;
    --text: #e6ece8;
    --text-dim: #97a59c;
    --accent: #46d977;
    --accent-strong: #6ef39c;
    --accent-soft: rgba(70, 217, 119, 0.12);
    --border: #22302a;
    --code-bg: #0e1511;
    --code-text: #cfe0d4;
    --term-bg: #080b09;
    --term-text: #c4d3c8;
    --term-green: #46d977;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.35);
    --nav-bg: rgba(11, 15, 12, 0.92);
    color-scheme: dark;
}

/* ---------- base ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font: 16px/1.65 "Segoe UI", system-ui, -apple-system, "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    overflow-x: clip; /* page never scrolls horizontally */
}
a { color: var(--accent-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre, .cmd, kbd {
    font-family: "Cascadia Mono", "JetBrains Mono", Consolas, "Courier New", monospace;
}
code {
    background: var(--code-bg);
    color: var(--code-text);
    padding: 1px 6px;
    border-radius: 5px;
    font-size: 0.9em;
    word-break: break-word;
}
pre {
    background: var(--code-bg);
    color: var(--code-text);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 14px 16px;
    overflow-x: auto; /* block-level scroll, not page scroll */
    font-size: 13.5px;
    line-height: 1.55;
}
h1, h2, h3 { line-height: 1.25; }
img { max-width: 100%; height: auto; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ---------- nav ---------- */
.nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}
.nav-inner {
    display: flex;
    align-items: center;
    gap: 12px;
    height: 60px;
}
.brand {
    font-weight: 700;
    font-size: 17px;
    color: var(--text);
    letter-spacing: 0.2px;
    white-space: nowrap;
    margin-right: auto;
}
.brand:hover { text-decoration: none; }
.brand .p { color: var(--accent); }
.nav-links {
    display: flex;
    align-items: center;
    gap: 4px;
}
.nav-links > a {
    color: var(--text-dim);
    padding: 8px 11px;
    border-radius: 8px;
    font-size: 14.5px;
    white-space: nowrap;
}
.nav-links > a:hover { color: var(--text); background: var(--accent-soft); text-decoration: none; }
.nav-links > a.active { color: var(--accent-strong); font-weight: 600; }
.nav-links > a.cta {
    color: var(--accent-strong);
    border: 1px solid var(--border);
    background: var(--card);
    font-weight: 600;
    margin-left: 4px;
}
.nav-ctrl {
    display: flex;
    align-items: center;
    gap: 8px;
}
.seg {
    display: inline-flex;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: var(--card);
}
.seg button {
    border: 0;
    background: transparent;
    color: var(--text-dim);
    font: 600 13px/1 inherit;
    font-family: inherit;
    padding: 7px 10px;
    cursor: pointer;
}
.seg button.active {
    background: var(--accent);
    color: #fff;
}
.seg button:focus-visible, .icon-btn:focus-visible, #nav-toggle:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
.icon-btn {
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    border-radius: 8px;
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 16px;
    line-height: 1;
    padding: 0;
}
.icon-btn:hover { border-color: var(--accent); }
#nav-toggle {
    display: none;
    border: 1px solid var(--border);
    background: var(--card);
    border-radius: 8px;
    width: 40px;
    height: 34px;
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 0;
}
#nav-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: transform 0.2s, opacity 0.2s;
}
body.nav-open #nav-toggle span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
body.nav-open #nav-toggle span:nth-child(2) { opacity: 0; }
body.nav-open #nav-toggle span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ---------- buttons ---------- */
.btn {
    display: inline-block;
    padding: 11px 20px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 15px;
    border: 1px solid transparent;
    cursor: pointer;
    white-space: nowrap;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
    background: var(--accent);
    color: #ffffff;
}
html[data-theme="dark"] .btn-primary { color: #06120a; }
.btn-primary:hover { background: var(--accent-strong); }
.btn-ghost {
    background: transparent;
    color: var(--text);
    border-color: var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-strong); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; margin: 22px 0 4px; }

/* ---------- hero ---------- */
.hero {
    background:
        radial-gradient(1000px 420px at 85% -10%, var(--accent-soft), transparent),
        var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 64px 0 56px;
}
.hero-grid {
    display: grid;
    grid-template-columns: 1.08fr 0.92fr;
    gap: 44px;
    align-items: center;
}
.hero h1 {
    font-size: 44px;
    font-weight: 800;
    margin: 0 0 16px;
    letter-spacing: -0.5px;
}
.hero h1 .accent { color: var(--accent); }
.tagline { color: var(--text-dim); font-size: 17px; margin: 0 0 6px; max-width: 560px; }
.tagline b { color: var(--text); }

/* terminal demo card */
.terminal-card {
    background: var(--term-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}
.terminal-card .bar {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 9px 12px;
    background: rgba(255, 255, 255, 0.04);
    border-bottom: 1px solid var(--border);
}
.terminal-card .dot { width: 11px; height: 11px; border-radius: 50%; }
.dot.r { background: #ff5f56; } .dot.y { background: #ffbd2e; } .dot.g { background: #27c93f; }
.terminal-card .t { color: #7e8f85; font-size: 12.5px; margin-left: 6px; font-family: Consolas, monospace; }
.terminal-card pre {
    margin: 0;
    border: 0;
    background: transparent;
    color: var(--term-text);
    font-size: 13px;
    min-height: 300px;
}
.terminal-card .c { color: var(--term-green); font-weight: 700; }
.terminal-card .a { color: #9fd0ff; }
.terminal-card .d { color: #6f8076; }

/* ---------- stats strip ---------- */
.stats-strip {
    border-bottom: 1px solid var(--border);
    background: var(--bg-soft);
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 22px 24px;
}
.stat { text-align: center; }
.stat .n {
    font-size: 30px;
    font-weight: 800;
    color: var(--accent-strong);
    font-variant-numeric: tabular-nums;
}
.stat .l { color: var(--text-dim); font-size: 13px; }

/* ---------- sections ---------- */
.section { padding: 64px 0; border-bottom: 1px solid var(--border); }
.section.alt { background: var(--bg-soft); }
.section h2 { font-size: 30px; margin: 0 0 10px; font-weight: 800; letter-spacing: -0.3px; }
.section .sub { color: var(--text-dim); max-width: 760px; margin: 0 0 30px; }

/* feature cards */
.feat-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}
.feat {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
}
.feat .k {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--accent-strong);
    background: var(--accent-soft);
    border-radius: 5px;
    padding: 2px 8px;
    margin-bottom: 10px;
    font-family: Consolas, monospace;
}
.feat h3 { margin: 0 0 8px; font-size: 17px; }
.feat p { margin: 0; color: var(--text-dim); font-size: 14.5px; }
.feat ul { margin: 8px 0 0; padding-left: 18px; color: var(--text-dim); font-size: 14px; }
.feat li { margin: 3px 0; }

/* architecture ascii figure */
.arch pre {
    font-size: 13px;
    line-height: 1.5;
    color: var(--code-text);
}
.arch .hb { color: var(--accent-strong); font-weight: 700; }
.arch .hl { color: var(--accent-strong); font-weight: 700; }

/* quickstart steps */
.steps { display: grid; gap: 16px; }
.step {
    display: flex;
    gap: 16px;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 18px 20px;
}
.step > div { min-width: 0; flex: 1 1 0; } /* let .cmd scroll inside */
.step .n {
    flex: 0 0 34px;
    height: 34px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
}
html[data-theme="dark"] .step .n { color: #06120a; }
.step h3 { margin: 4px 0 6px; font-size: 16.5px; }
.step p { margin: 0 0 8px; color: var(--text-dim); font-size: 14.5px; }
.cmd {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 13px;
    color: var(--code-text);
    overflow-x: auto;
    white-space: pre;
    max-width: 100%;
}
.cmd .c { color: var(--accent-strong); font-weight: 700; }
.cmd span { white-space: pre; }

/* screenshots */
.shots { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.shot {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 10px;
    box-shadow: var(--shadow);
}
.shot img { border-radius: 7px; display: block; width: 100%; }
.shot .cap {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 6px 2px;
    font-size: 13.5px;
    color: var(--text-dim);
}
.shot .tag {
    background: var(--accent-soft);
    color: var(--accent-strong);
    border-radius: 5px;
    padding: 1px 8px;
    font-size: 12px;
    font-family: Consolas, monospace;
}

/* tables (spec / group tables on architecture page) */
.tbl-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
table.tbl {
    width: 100%;
    border-collapse: collapse;
    background: var(--card);
    font-size: 14px;
    min-width: 560px;
}
table.tbl th, table.tbl td {
    text-align: left;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}
table.tbl th {
    background: var(--bg-soft);
    font-size: 12.5px;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    color: var(--text-dim);
    white-space: nowrap;
}
table.tbl tr:last-child td { border-bottom: 0; }
table.tbl td.num { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--accent-strong); white-space: nowrap; }
table.tbl td code { background: transparent; padding: 0; color: var(--accent-strong); }

/* ---------- download page ---------- */
.dl-head { padding: 52px 0 8px; }
.dl-head h1 { font-size: 36px; margin: 0 0 8px; font-weight: 800; }
.dl-head .sub { color: var(--text-dim); margin: 0; }
.dl-head .v { color: var(--accent-strong); font-weight: 700; }
.dl-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    margin: 26px 0 10px;
}
.dl-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
}
.dl-card .type {
    font-size: 11.5px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--accent-strong);
    background: var(--accent-soft);
    border-radius: 5px;
    padding: 2px 8px;
    align-self: flex-start;
    margin-bottom: 10px;
    font-family: Consolas, monospace;
}
.dl-card h3 { margin: 0 0 8px; font-size: 16px; word-break: break-all; }
.dl-card .desc { color: var(--text-dim); font-size: 14px; margin: 0 0 12px; flex: 1; }
.dl-card .meta { font-size: 13.5px; color: var(--text-dim); margin-bottom: 8px; }
.sha {
    font-family: Consolas, monospace;
    font-size: 12px;
    color: var(--text-dim);
    background: var(--code-bg);
    border: 1px dashed var(--border);
    border-radius: 7px;
    padding: 7px 10px;
    word-break: break-all;
    margin-bottom: 14px;
}
.hist-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
table.hist {
    width: 100%;
    border-collapse: collapse;
    background: var(--card);
    font-size: 13.5px;
    min-width: 640px;
}
table.hist th, table.hist td {
    text-align: left;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
}
table.hist th {
    background: var(--bg-soft);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    color: var(--text-dim);
    white-space: nowrap;
}
table.hist tr:last-child td { border-bottom: 0; }
table.hist td.v { font-weight: 700; color: var(--accent-strong); white-space: nowrap; }
table.hist td.sha { padding: 8px 14px; }

/* ---------- about page ---------- */
.about-cols {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 26px;
    align-items: start;
}
.about-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 22px;
    box-shadow: var(--shadow);
    margin-bottom: 18px;
}
.about-card h3 { margin: 0 0 8px; font-size: 17px; }
.about-card p { margin: 0 0 10px; color: var(--text-dim); font-size: 14.5px; }
.about-card ul { margin: 0; padding-left: 18px; color: var(--text-dim); font-size: 14.5px; }
.about-card li { margin: 4px 0; }
.mail { font-size: 15px; }

/* ---------- footer ---------- */
footer.site {
    margin-top: auto;
    background: var(--bg-soft);
    border-top: 1px solid var(--border);
    padding: 44px 0 30px;
}
body { min-height: 100vh; display: flex; flex-direction: column; } /* sticky footer */
main { flex: 1 0 auto; }
.foot-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 26px;
    margin-bottom: 26px;
}
.foot-grid .h {
    font-size: 12.5px;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--text-dim);
    margin-bottom: 10px;
    font-weight: 700;
}
.foot-grid .col a { display: block; color: var(--text-dim); padding: 3px 0; font-size: 14px; }
.foot-grid .col a:hover { color: var(--accent-strong); }
.foot-note {
    border-top: 1px solid var(--border);
    padding-top: 16px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 22px;
    color: var(--text-dim);
    font-size: 13px;
}

/* skip link (a11y) */
.skip {
    position: absolute;
    left: -9999px;
    top: 0;
    background: var(--accent);
    color: #fff;
    padding: 8px 16px;
    border-radius: 0 0 8px 0;
    z-index: 100;
}
.skip:focus { left: 0; }

/* grid items must be allowed to shrink below content width, or
   long <pre> children blow out the page at 390px */
.hero-grid > *, .feat-grid > *, .stats-grid > *, .dl-grid > *,
.shots > *, .about-cols > *, .steps > *, .btn-row > *,
.foot-grid > * { min-width: 0; }
pre, .cmd, .tbl-scroll, .hist-scroll { max-width: 100%; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
    .nav-inner { height: 56px; }
    #nav-toggle { display: inline-flex; }
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
        flex-direction: column;
        align-items: stretch;
        padding: 10px 16px 14px;
        gap: 2px;
    }
    body.nav-open .nav-links { display: flex; }
    .nav-links > a { padding: 12px 10px; border-radius: 8px; font-size: 15.5px; }
    .hero { padding: 44px 0 40px; }
    .hero-grid { grid-template-columns: 1fr; gap: 30px; }
    .hero h1 { font-size: 34px; }
    .feat-grid { grid-template-columns: repeat(2, 1fr); }
    .about-cols { grid-template-columns: 1fr; }
    .shots { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
    .wrap { padding: 0 16px; }
    .stats-grid { padding: 16px 8px; }
    .hero h1 { font-size: 29px; }
    .section { padding: 44px 0; }
    .section h2 { font-size: 25px; }
    .feat-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .dl-grid { grid-template-columns: 1fr; }
    .foot-grid { grid-template-columns: 1fr; }
    .step { padding: 15px 16px; gap: 12px; }
    .terminal-card pre { font-size: 12px; }
    .arch pre { font-size: 11.5px; }
    .seg button { padding: 7px 8px; }
    .btn { width: 100%; text-align: center; }
    .btn-row { margin-left: -0px; }
    .stat .n { font-size: 24px; }
}

/* reduced motion */
@media (prefers-reduced-motion: reduce) {
    * { transition: none !important; animation: none !important; }
    .btn:hover { transform: none; }
}

/* ===================== 2.0.0 motion layer =====================
   Line-by-line terminal reveal, scroll-reveal for sections and
   cards, and the count-up stats. All disabled when the user asks
   for reduced motion (app.js short-circuits; these rules are the
   no-JS / reduced-motion defaults). */

/* terminal lines: staggered fade+rise */
.terminal-card pre .tl {
  display: block;
  opacity: 0;
  transform: translateY(4px);
  animation: tl-in .32s ease-out forwards;
}
@keyframes tl-in {
  to { opacity: 1; transform: none; }
}
.terminal-card pre .tl.caret-line::after {
  content: "\2588";
  animation: caret-blink 1s steps(1) infinite;
  color: var(--fg, #46d977);
}
@keyframes caret-blink {
  50% { opacity: 0; }
}

/* scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s ease, transform .5s ease;
}
.reveal.in {
  opacity: 1;
  transform: none;
}
/* stagger the feature cards inside a revealed section */
.feat.reveal:nth-child(3n+2) { transition-delay: .07s; }
.feat.reveal:nth-child(3n)   { transition-delay: .14s; }

@media (prefers-reduced-motion: reduce) {
  .terminal-card pre .tl { opacity: 1; transform: none; animation: none; }
  .terminal-card pre .tl.caret-line::after { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* subtle lift on the terminal card (hero) */
.terminal-card {
  transition: transform .35s ease, box-shadow .35s ease;
}
.terminal-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 50px rgba(0, 0, 0, .35);
}