/* ============================================================
   SSHKeeper Landing — refined visual system
   ------------------------------------------------------------
   Design tokens → base → layout → components → sections.
   Light + dark via prefers-color-scheme. No JS, no externals.
   ============================================================ */

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; border: 0; background: none; color: inherit; cursor: pointer; }
:focus-visible { outline: 2px solid var(--ring); outline-offset: 3px; border-radius: var(--radius-sm); }

/* ===== Design Tokens (light) ===== */
:root {
    --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "PingFang SC", "Helvetica Neue", Inter, sans-serif;
    --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Monaco, Consolas, monospace;

    --fg: #1d1d1f;
    --fg-soft: #515156;
    --fg-mute: #86868b;
    --bg: #fbfbfd;
    --bg-elev: #ffffff;
    --bg-subtle: #f5f5f7;
    --bg-deep: #ededf0;
    --accent: #0071e3;
    --accent-hover: #0077ed;
    --accent-pressed: #006edb;
    --accent-soft: rgba(0, 113, 227, .08);
    --accent-bg: rgba(0, 113, 227, .12);
    --green: #1f8a3c;
    --orange: #b25800;
    --border: rgba(0, 0, 0, .06);
    --border-strong: rgba(0, 0, 0, .1);
    --ring: rgba(0, 113, 227, .45);

    --blob-a: rgba(0, 113, 227, .18);
    --blob-b: rgba(255, 138, 70, .14);

    --shadow-xs: 0 1px 2px rgba(0,0,0,.04);
    --shadow-sm: 0 2px 4px rgba(0,0,0,.04), 0 4px 14px rgba(0,0,0,.05);
    --shadow-md: 0 10px 28px rgba(0,0,0,.08);
    --shadow-mockup: 0 40px 80px -30px rgba(0,0,0,.22), 0 2px 8px rgba(0,0,0,.05);
    --shadow-cta-hover: 0 12px 30px rgba(0,113,227,.32);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-card: 18px;
    --radius-mockup: 14px;
    --radius-pill: 980px;

    --ease-out: cubic-bezier(.22, 1, .36, 1);
    --ease-in-out: cubic-bezier(.65, 0, .35, 1);
    --dur-fast: 150ms;
    --dur-base: 220ms;
    --dur-slow: 380ms;

    --container: 1100px;
    --container-narrow: 760px;
    --section-y: clamp(80px, 11vw, 140px);
    --nav-h: 56px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --fg: #f5f5f7;
        --fg-soft: #c5c5ca;
        --fg-mute: #86868b;
        --bg: #0a0a0c;
        --bg-elev: #161618;
        --bg-subtle: #1c1c1f;
        --bg-deep: #232325;
        --accent: #2997ff;
        --accent-hover: #3aa5ff;
        --accent-pressed: #1f8eff;
        --accent-soft: rgba(41, 151, 255, .12);
        --accent-bg: rgba(41, 151, 255, .18);
        --green: #30d158;
        --orange: #ffb454;
        --border: rgba(255, 255, 255, .08);
        --border-strong: rgba(255, 255, 255, .14);
        --ring: rgba(41, 151, 255, .5);
        --blob-a: rgba(41, 151, 255, .22);
        --blob-b: rgba(255, 138, 70, .16);
        --shadow-xs: 0 1px 2px rgba(0,0,0,.4);
        --shadow-sm: 0 2px 4px rgba(0,0,0,.5), 0 4px 14px rgba(0,0,0,.4);
        --shadow-md: 0 10px 28px rgba(0,0,0,.5);
        --shadow-mockup: 0 40px 80px -30px rgba(0,0,0,.7), 0 2px 10px rgba(0,0,0,.45);
        --shadow-cta-hover: 0 12px 30px rgba(41,151,255,.35);
    }
}

/* ===== Base ===== */
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--fg);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}
h1, h2, h3, h4 { line-height: 1.1; letter-spacing: -.025em; font-weight: 600; color: var(--fg); }
h1 { font-size: clamp(44px, 6.4vw, 76px); letter-spacing: -.035em; font-weight: 700; }
h2 { font-size: clamp(32px, 4.2vw, 48px); letter-spacing: -.03em; }
h3 { font-size: 20px; font-weight: 600; }
h4 { font-size: 15px; font-weight: 600; }
p { color: var(--fg-soft); }

html[lang="zh"] [data-lang="en"] { display: none; }
html[lang="en"] [data-lang="zh"] { display: none; }

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ===== Layout ===== */
.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: var(--container-narrow); margin: 0 auto; padding: 0 24px; }

section { padding-top: var(--section-y); padding-bottom: var(--section-y); }
.section-head { text-align: center; margin-bottom: clamp(48px, 7vw, 80px); }
.section-eyebrow {
    display: inline-block;
    font-size: 13px;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: .04em;
    text-transform: uppercase;
    margin-bottom: 12px;
}
.section-sub {
    margin-top: 14px;
    font-size: clamp(17px, 1.8vw, 19px);
    color: var(--fg-soft);
    max-width: 580px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================================
   Nav
   ============================================================ */
nav#nav {
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--nav-h);
    backdrop-filter: saturate(180%) blur(24px);
    -webkit-backdrop-filter: saturate(180%) blur(24px);
    background: color-mix(in oklab, var(--bg) 78%, transparent);
    border-bottom: 1px solid var(--border);
}
.nav-inner {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.nav-logo {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 15px;
    color: var(--fg);
}
.nav-logo svg { color: var(--accent); }
.nav-actions { display: flex; align-items: center; gap: 10px; }

.lang-switch {
    display: inline-flex;
    padding: 3px;
    border-radius: var(--radius-pill);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
}
.lang-switch button {
    padding: 4px 11px;
    border-radius: var(--radius-pill);
    font-size: 12px;
    font-weight: 500;
    color: var(--fg-soft);
    transition: color var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}
.lang-switch button[aria-current="true"] {
    background: var(--bg-elev);
    color: var(--fg);
    box-shadow: var(--shadow-xs);
}

/* ============================================================
   Buttons
   ============================================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    border-radius: var(--radius-pill);
    padding: 10px 18px;
    font-weight: 500;
    font-size: 15px;
    transition: background var(--dur-fast) var(--ease-out),
                color var(--dur-fast) var(--ease-out),
                transform var(--dur-fast) var(--ease-out),
                box-shadow var(--dur-base) var(--ease-out);
    will-change: transform;
}
.btn:active { transform: scale(.97); }
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); box-shadow: var(--shadow-cta-hover); }
.btn-secondary { background: var(--accent-soft); color: var(--accent); }
.btn-secondary:hover { background: var(--accent-bg); }
.btn-ghost { color: var(--fg-soft); }
.btn-ghost:hover { color: var(--fg); }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btn-lg { padding: 14px 26px; font-size: 17px; }

/* ============================================================
   Hero
   ============================================================ */
#hero {
    position: relative;
    padding-top: clamp(72px, 10vw, 120px);
    padding-bottom: clamp(64px, 8vw, 96px);
    overflow: hidden;
    text-align: center;
}
#hero::before, #hero::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    z-index: 0;
    pointer-events: none;
}
#hero::before {
    width: 560px; height: 560px;
    background: var(--blob-a);
    top: -120px;
    left: -100px;
    opacity: .9;
}
#hero::after {
    width: 480px; height: 480px;
    background: var(--blob-b);
    top: 40px;
    right: -120px;
    opacity: .75;
}
.hero-inner { position: relative; z-index: 1; }

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: var(--radius-pill);
    background: color-mix(in oklab, var(--bg-elev) 80%, transparent);
    border: 1px solid var(--border);
    font-size: 13px;
    font-weight: 500;
    color: var(--fg-soft);
    margin-bottom: 24px;
    backdrop-filter: blur(8px);
}
.hero-eyebrow .dot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 0 3px color-mix(in oklab, var(--green) 30%, transparent);
}

#hero h1 { margin: 0 auto; max-width: 880px; }
#hero h1 .accent-grad {
    background: linear-gradient(135deg, var(--accent) 0%, color-mix(in oklab, var(--accent) 50%, #b794f4) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.hero-sub {
    margin: 22px auto 0;
    max-width: 640px;
    font-size: clamp(17px, 2vw, 20px);
    color: var(--fg-soft);
    line-height: 1.55;
}
.hero-cta {
    margin-top: 36px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
}
.hero-meta {
    margin-top: 16px;
    font-size: 12px;
    color: var(--fg-mute);
}

.hero-mockup-wrap {
    margin-top: clamp(48px, 6vw, 72px);
    perspective: 1200px;
}
.hero-mockup-wrap .mockup {
    transform: rotateX(2deg);
    transform-origin: top center;
    max-width: 920px;
    margin: 0 auto;
}

/* ============================================================
   Mockup window (shared)
   ============================================================ */
.mockup {
    border-radius: var(--radius-mockup);
    background: var(--bg-elev);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-mockup);
    overflow: hidden;
    position: relative;
}
.mockup-chrome {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 11px 14px;
    background: var(--bg-subtle);
    border-bottom: 1px solid var(--border);
}
.dot { width: 12px; height: 12px; border-radius: 50%; display: inline-block; }
.dot-r { background: #ff5f57; }
.dot-y { background: #febc2e; }
.dot-g { background: #28c840; }
.mockup-title {
    flex: 1;
    text-align: center;
    font-size: 12px;
    color: var(--fg-mute);
    font-weight: 500;
}
.mockup-body {
    padding: 18px 20px;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.6;
    background: var(--bg-elev);
}
.mock-term { white-space: pre; margin: 0; color: var(--fg); }
.mt-prompt { color: var(--accent); font-weight: 500; }
.mt-cmd    { color: var(--fg); }
.mt-muted  { color: var(--fg-mute); }
.mt-out    { color: var(--fg); opacity: .82; }
.mt-kw     { color: #c041ff; }
.mt-str    { color: var(--green); }
.mt-num    { color: var(--orange); }
.mt-caret  {
    display: inline-block;
    width: 7px; height: 14px;
    background: var(--accent);
    vertical-align: -2px;
    animation: blink 1s steps(2, end) infinite;
    border-radius: 1px;
}
@keyframes blink { 50% { opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .mt-caret { animation: none; } }

/* ============================================================
   Trust strip
   ============================================================ */
#trust {
    padding-top: clamp(40px, 5vw, 56px);
    padding-bottom: clamp(40px, 5vw, 56px);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    background: var(--bg-subtle);
}
.trust-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-around;
    gap: 28px 40px;
}
.trust-item {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--fg-soft);
    font-size: 14px;
    font-weight: 500;
}
.trust-item svg {
    width: 22px; height: 22px;
    color: var(--accent);
    flex: 0 0 22px;
}

/* ============================================================
   Bento Features
   ============================================================ */
.bento {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.bento-card {
    grid-column: span 1;
    background: var(--bg-elev);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    padding: 28px;
    transition: transform var(--dur-base) var(--ease-out),
                box-shadow var(--dur-base) var(--ease-out),
                border-color var(--dur-base) var(--ease-out);
    position: relative;
    overflow: hidden;
}
.bento-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--border-strong);
}
.bento-card.wide { grid-column: span 2; }
.bento-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: var(--accent-soft);
    color: var(--accent);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 18px;
    transition: transform var(--dur-base) var(--ease-out);
}
.bento-card:hover .bento-icon { transform: scale(1.05); }
.bento-card h3 { margin-bottom: 8px; font-size: 19px; }
.bento-card p { font-size: 15px; color: var(--fg-soft); margin: 0; }
.bento-card.wide p { font-size: 16px; max-width: 520px; }
.bento-card.wide h3 { font-size: 22px; }

@media (max-width: 900px) {
    .bento { grid-template-columns: 1fr 1fr; }
    .bento-card.wide { grid-column: span 2; }
}
@media (max-width: 560px) {
    .bento { grid-template-columns: 1fr; }
    .bento-card.wide { grid-column: span 1; }
}

/* ============================================================
   Screenshots
   ============================================================ */
#screenshots .container { display: grid; gap: clamp(80px, 10vw, 140px); }
.shot-row {
    display: grid;
    grid-template-columns: 1fr 1.25fr;
    align-items: center;
    gap: clamp(40px, 6vw, 80px);
}
.shot-row.reverse { grid-template-columns: 1.25fr 1fr; }
.shot-row.reverse .mockup { order: -1; }
.shot-copy h2 { margin-bottom: 14px; max-width: 460px; }
.shot-copy p { font-size: 17px; color: var(--fg-soft); max-width: 440px; }
.shot-copy ul { margin-top: 20px; display: grid; gap: 10px; }
.shot-copy li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 14px;
    color: var(--fg-soft);
}
.shot-copy li::before {
    content: "";
    flex: 0 0 6px;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
    margin-top: 9px;
}

.mockup-tabs {
    display: flex;
    gap: 4px;
    padding: 6px 14px;
    background: color-mix(in oklab, var(--bg-elev) 96%, var(--fg) 4%);
    border-bottom: 1px solid var(--border);
}
.mock-tab {
    font-size: 12px;
    padding: 4px 10px;
    border-radius: 6px;
    color: var(--fg-soft);
    font-family: var(--font-mono);
    line-height: 1.4;
}
.mock-tab.active { background: var(--accent-soft); color: var(--accent); }
.mock-tab.add { color: var(--fg-mute); }

.mockup-body-db {
    display: grid;
    grid-template-columns: 196px 1fr;
    padding: 0;
    min-height: 320px;
}
.mock-sidebar {
    border-right: 1px solid var(--border);
    padding: 14px;
    font-family: var(--font-mono);
    font-size: 12px;
    background: var(--bg-subtle);
}
.mock-search {
    padding: 5px 8px;
    border: 1px solid var(--border);
    background: var(--bg-elev);
    border-radius: 6px;
    color: var(--fg-mute);
    margin-bottom: 12px;
    font-size: 11px;
}
.mock-sidebar ul { display: flex; flex-direction: column; gap: 2px; }
.mock-sidebar li {
    padding: 5px 8px;
    border-radius: 5px;
    display: flex;
    justify-content: space-between;
    color: var(--fg);
}
.mock-sidebar li small { color: var(--fg-mute); }
.mock-sidebar li.active { background: var(--accent-soft); color: var(--accent); }
.mock-sidebar li.active small { color: var(--accent); opacity: .85; }

.mock-pane { padding: 14px 18px; }
.mock-tabbar { display: flex; gap: 4px; margin-bottom: 14px; }
.mock-table {
    width: 100%;
    font-family: var(--font-mono);
    font-size: 12px;
    border-collapse: collapse;
}
.mock-table th, .mock-table td {
    text-align: left;
    padding: 7px 8px;
    border-bottom: 1px solid var(--border);
}
.mock-table th { color: var(--fg-mute); font-weight: 500; font-size: 11px; text-transform: uppercase; letter-spacing: .04em; }
.mock-table tr.hl { background: var(--accent-soft); }
.mock-table td.num { font-variant-numeric: tabular-nums; color: var(--fg); }
.mock-status-paid { color: var(--green); font-weight: 600; }
.mock-status-pend { color: var(--orange); }

@media (max-width: 820px) {
    .shot-row, .shot-row.reverse { grid-template-columns: 1fr; }
    .shot-row.reverse .mockup { order: 0; }
}

/* ============================================================
   Download
   ============================================================ */
#download { background: var(--bg-subtle); }
.dl-card {
    max-width: 720px;
    margin: 0 auto;
    padding: clamp(36px, 5vw, 48px);
    border-radius: var(--radius-card);
    background: var(--bg-elev);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    text-align: center;
}
.dl-title { font-size: clamp(22px, 2.4vw, 26px); font-weight: 600; margin-bottom: 4px; }
.dl-meta {
    color: var(--fg-mute);
    font-size: 13px;
    margin-bottom: 24px;
    font-variant-numeric: tabular-nums;
}
.dl-meta .dot-sep { margin: 0 6px; opacity: .5; }

.dl-reqs {
    margin: 28px auto 0;
    display: grid;
    gap: 10px;
    max-width: 360px;
    text-align: left;
}
.dl-reqs li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 14px;
    color: var(--fg);
}
.dl-reqs svg { color: var(--green); flex: 0 0 16px; margin-top: 2px; }

.dl-sha {
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}
.sha-label {
    font-size: 11px;
    color: var(--fg-mute);
    text-transform: uppercase;
    letter-spacing: .08em;
    font-weight: 600;
}
#sha-value {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--fg-soft);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    padding: 5px 10px;
    border-radius: 6px;
    overflow-wrap: anywhere;
    max-width: 100%;
}
.btn-copy {
    font-size: 12px;
    padding: 5px 12px;
    border-radius: var(--radius-pill);
    background: var(--accent-soft);
    color: var(--accent);
    font-weight: 500;
    transition: background var(--dur-fast) var(--ease-out);
}
.btn-copy:hover { background: var(--accent-bg); }
.btn-copy.copied { background: color-mix(in oklab, var(--green) 18%, transparent); color: var(--green); }

/* ============================================================
   FAQ
   ============================================================ */
.faq-list { display: grid; gap: 4px; }
.faq-list details {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--bg-elev);
    border: 1px solid var(--border);
    transition: border-color var(--dur-fast) var(--ease-out);
}
.faq-list details:hover { border-color: var(--border-strong); }
.faq-list summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 18px 22px;
    cursor: pointer;
    list-style: none;
    font-weight: 500;
    font-size: 16px;
    color: var(--fg);
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
    content: "";
    width: 18px; height: 18px;
    border-radius: 50%;
    flex: 0 0 18px;
    transition: transform var(--dur-base) var(--ease-out), color var(--dur-fast) var(--ease-out);
    color: var(--fg-soft);
    background-image:
        linear-gradient(currentColor, currentColor),
        linear-gradient(currentColor, currentColor);
    background-size: 9px 1.5px, 1.5px 9px;
    background-position: center;
    background-repeat: no-repeat;
}
.faq-list details[open] summary::after {
    transform: rotate(45deg);
    color: var(--accent);
}
.faq-body {
    padding: 0 22px 22px;
    color: var(--fg-soft);
    line-height: 1.65;
}
.faq-body p { margin: 0 0 10px; }
.faq-body p:last-child { margin-bottom: 0; }
.faq-body code {
    font-family: var(--font-mono);
    font-size: 13px;
    background: var(--bg-subtle);
    padding: 1px 6px;
    border-radius: 4px;
    color: var(--fg);
    border: 1px solid var(--border);
}
.faq-code {
    font-family: var(--font-mono);
    font-size: 13px;
    background: var(--bg-subtle);
    color: var(--fg);
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    overflow-x: auto;
    margin: 10px 0 0;
}
.faq-body a { color: var(--accent); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.faq-body a:hover { color: var(--accent-hover); }

/* ============================================================
   Footer
   ============================================================ */
footer#footer {
    padding: clamp(56px, 7vw, 72px) 24px;
    border-top: 1px solid var(--border);
    color: var(--fg-soft);
    background: var(--bg);
}
.footer-grid {
    max-width: var(--container);
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 40px;
    align-items: start;
}
.footer-brand strong {
    display: block;
    font-size: 15px;
    color: var(--fg);
    font-weight: 600;
    margin-bottom: 8px;
}
.footer-brand p {
    font-size: 13px;
    color: var(--fg-mute);
    max-width: 320px;
    line-height: 1.55;
}
.footer-col h4 {
    color: var(--fg-mute);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: .08em;
    text-transform: uppercase;
    margin-bottom: 14px;
}
.footer-col ul { display: grid; gap: 8px; }
.footer-col a, .footer-col li {
    font-size: 14px;
    color: var(--fg-soft);
    transition: color var(--dur-fast) var(--ease-out);
}
.footer-col a:hover { color: var(--fg); }
.footer-bottom {
    max-width: var(--container);
    margin: 40px auto 0;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    font-size: 12px;
    color: var(--fg-mute);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}

@media (max-width: 720px) {
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ===== Utility ===== */
[hidden] { display: none !important; }