/* BaseNotes website: shared design system (tokens, base, nav, buttons, footer, prose pages).
   Colours come from the iOS app's brand tokens (Assets.xcassets/Colors, UI/UX review §4). */

:root {
    color-scheme: light;
    --brand: #1565C0;
    --brand-hover: #0F559F;
    --brand-soft: #E8F0FB;
    --on-brand: #FFFFFF;
    --ink: #0E1218;
    --text-2: #5B6472;
    --bg: #FFFFFF;
    --bg-alt: #F6F7F9;
    --surface: #FFFFFF;
    --surface-raised: #FFFFFF;
    --line: #E3E6EB;
    --record: #E5383B;
    --success: #1E8E3E;
    --success-text: #16702F;
    --warning-bg: #FFF4E5;
    --warning-line: #B25E00;
    --glass: rgba(255, 255, 255, 0.72);
    --glow-1: rgba(21, 101, 192, 0.16);
    --glow-2: rgba(94, 158, 240, 0.14);
    --shadow-1: 0 1px 2px rgba(14, 18, 24, 0.06), 0 2px 8px rgba(14, 18, 24, 0.04);
    --shadow-2: 0 2px 6px rgba(14, 18, 24, 0.05), 0 16px 40px rgba(14, 18, 24, 0.08);
    --shadow-3: 0 30px 80px rgba(14, 18, 24, 0.18), 0 8px 24px rgba(14, 18, 24, 0.10);

    --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Inter", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --step--1: clamp(0.84rem, 0.82rem + 0.1vw, 0.9rem);
    --step-0: clamp(1rem, 0.97rem + 0.15vw, 1.0625rem);
    --step-1: clamp(1.13rem, 1.06rem + 0.3vw, 1.3rem);
    --step-2: clamp(1.35rem, 1.2rem + 0.7vw, 1.75rem);
    --step-3: clamp(1.85rem, 1.35rem + 2.2vw, 3rem);
    --step-4: clamp(2.25rem, 1.5rem + 3.2vw, 4rem);

    --space-1: 0.25rem; --space-2: 0.5rem; --space-3: 0.75rem; --space-4: 1rem;
    --space-5: 1.5rem; --space-6: 2rem; --space-7: 3rem; --space-8: 4rem;
    --section: clamp(4.5rem, 3rem + 6vw, 8.5rem);
    --gutter: clamp(1rem, 0.6rem + 2vw, 2rem);
    --maxw: 1180px;

    --r-chip: 8px; --r-button: 14px; --r-card: 20px; --r-sheet: 28px;
    --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        color-scheme: dark;
        --brand: #5E9EF0; --brand-hover: #7DB2F4; --brand-soft: #13233A; --on-brand: #0B0D11;
        --ink: #F2F4F7; --text-2: #A3ACB9; --bg: #0B0D11; --bg-alt: #101319;
        --surface: #161A21; --surface-raised: #1E232C; --line: #262B34;
        --record: #FF5A5F; --success: #3FB950; --success-text: #3FB950; --warning-bg: #2A2011; --warning-line: #F0A13A;
        --glass: rgba(11, 13, 17, 0.72); --glow-1: rgba(94, 158, 240, 0.20); --glow-2: rgba(21, 101, 192, 0.22);
        --shadow-1: 0 0 0 1px rgba(255, 255, 255, 0.04);
        --shadow-2: 0 0 0 1px rgba(255, 255, 255, 0.05), 0 16px 40px rgba(0, 0, 0, 0.35);
        --shadow-3: 0 30px 80px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 255, 255, 0.06);
    }
}
:root[data-theme="dark"] {
    color-scheme: dark;
    --brand: #5E9EF0; --brand-hover: #7DB2F4; --brand-soft: #13233A; --on-brand: #0B0D11;
    --ink: #F2F4F7; --text-2: #A3ACB9; --bg: #0B0D11; --bg-alt: #101319;
    --surface: #161A21; --surface-raised: #1E232C; --line: #262B34;
    --record: #FF5A5F; --success: #3FB950; --success-text: #3FB950; --warning-bg: #2A2011; --warning-line: #F0A13A;
    --glass: rgba(11, 13, 17, 0.72); --glow-1: rgba(94, 158, 240, 0.20); --glow-2: rgba(21, 101, 192, 0.22);
    --shadow-1: 0 0 0 1px rgba(255, 255, 255, 0.04);
    --shadow-2: 0 0 0 1px rgba(255, 255, 255, 0.05), 0 16px 40px rgba(0, 0, 0, 0.35);
    --shadow-3: 0 30px 80px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 255, 255, 0.06);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 5rem; }
body {
    font-family: var(--font);
    font-size: var(--step-0);
    line-height: 1.6;
    color: var(--ink);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}
img, svg, picture { display: block; max-width: 100%; }
img { height: auto; }
a { color: var(--brand); text-underline-offset: 0.18em; }
a:hover { color: var(--brand-hover); }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 3px; border-radius: 6px; }
::selection { background: var(--brand-soft); color: var(--ink); }
h1, h2, h3 { line-height: 1.1; letter-spacing: -0.025em; text-wrap: balance; }
p { text-wrap: pretty; }
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.visually-hidden {
    position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
    position: absolute; left: var(--gutter); top: -3rem; z-index: 100;
    background: var(--ink); color: var(--bg); padding: 0.6rem 1rem; border-radius: var(--r-chip);
}
.skip-link:focus { top: 0.75rem; color: var(--bg); }

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 0.55rem;
    min-height: 48px; padding: 0 1.3rem; border-radius: var(--r-button);
    font: 600 var(--step-0)/1 var(--font); letter-spacing: -0.01em;
    text-decoration: none; border: 1px solid transparent; cursor: pointer;
    transition: transform 0.2s var(--ease), background-color 0.2s, box-shadow 0.2s, color 0.2s;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(0.98); }
.btn-primary { background: var(--brand); color: var(--on-brand); box-shadow: 0 6px 18px -6px var(--glow-1); }
.btn-primary:hover { background: var(--brand-hover); color: var(--on-brand); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { color: var(--ink); background: var(--bg-alt); }
.btn-sm { min-height: 40px; padding: 0 1rem; font-size: var(--step--1); border-radius: 12px; }

/* App Store-style download button (replace with Apple's official badge at launch). */
.btn-store {
    background: var(--ink); color: var(--bg); min-height: 56px; padding: 0 1.4rem 0 1.1rem; gap: 0.75rem;
    border-radius: 16px; text-align: left;
}
.btn-store:hover { color: var(--bg); background: var(--ink); box-shadow: var(--shadow-2); }
.btn-store svg { width: 26px; height: 26px; flex: none; }
.btn-store span { display: grid; line-height: 1.15; }
.btn-store small { font-size: 0.72rem; font-weight: 500; opacity: 0.8; letter-spacing: 0.01em; }
.btn-store strong { font-size: 1.12rem; font-weight: 650; letter-spacing: -0.015em; }

/* ---------- Nav ---------- */
.site-nav {
    position: sticky; top: 0; z-index: 50;
    border-bottom: 1px solid transparent;
    transition: background-color 0.3s, border-color 0.3s, backdrop-filter 0.3s;
}
.site-nav.is-scrolled, .site-nav.is-open {
    background: var(--glass);
    -webkit-backdrop-filter: saturate(180%) blur(18px);
    backdrop-filter: saturate(180%) blur(18px);
    border-bottom-color: var(--line);
}
.nav-inner { display: flex; align-items: center; gap: var(--space-5); min-height: 68px; }
.brand {
    display: inline-flex; align-items: center; gap: 0.6rem; margin-right: auto;
    color: var(--ink); text-decoration: none; font-weight: 700; font-size: 1.15rem; letter-spacing: -0.02em;
}
.brand:hover { color: var(--ink); }
.brand img { width: 32px; height: 32px; border-radius: 9px; box-shadow: 0 0 0 1px var(--line); }
.nav-links { display: flex; gap: 0.25rem; list-style: none; padding: 0; }
.nav-links a {
    display: block; padding: 0.5rem 0.8rem; border-radius: 10px;
    color: var(--text-2); text-decoration: none; font-size: 0.95rem; font-weight: 500;
    transition: color 0.2s, background-color 0.2s;
}
.nav-links a:hover { color: var(--ink); background: var(--bg-alt); }
.nav-actions { display: flex; align-items: center; gap: 0.5rem; }
.icon-btn {
    display: inline-grid; place-items: center; width: 44px; height: 44px;
    border-radius: 12px; border: 1px solid var(--line); background: transparent; color: var(--ink); cursor: pointer;
    transition: background-color 0.2s;
}
.icon-btn:hover { background: var(--bg-alt); }
.icon-btn svg { width: 20px; height: 20px; }
.theme-toggle .icon-moon, :root[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: none; }
    :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: block; }
}
.menu-toggle { display: none; }
.menu-toggle .icon-close, .site-nav.is-open .menu-toggle .icon-menu { display: none; }
.site-nav.is-open .menu-toggle .icon-close { display: block; }

@media (max-width: 880px) {
    .menu-toggle { display: inline-grid; }
    .nav-cta { display: none; }
    .nav-links {
        position: absolute; inset: 100% 0 auto 0; flex-direction: column; gap: 0;
        padding: var(--space-3) var(--gutter) var(--space-5);
        background: var(--bg); border-bottom: 1px solid var(--line); box-shadow: var(--shadow-2);
        display: none;
    }
    .site-nav.is-open .nav-links { display: flex; }
    .nav-links a { padding: 0.85rem 0.5rem; font-size: 1.05rem; color: var(--ink); border-radius: 0; border-bottom: 1px solid var(--line); }
    .nav-links li:last-child a { border-bottom: 0; }
}

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: var(--bg-alt); padding: var(--space-7) 0 var(--space-6); color: var(--text-2); font-size: var(--step--1); }
.footer-grid { display: grid; grid-template-columns: 1.4fr repeat(2, 1fr); gap: var(--space-6); }
.footer-grid p { margin-top: var(--space-3); max-width: 34ch; }
.footer-grid h2 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink); margin-bottom: var(--space-3); font-weight: 650; }
.footer-grid ul { list-style: none; padding: 0; display: grid; gap: 0.4rem; }
.footer-grid a { color: var(--text-2); text-decoration: none; }
.footer-grid a:hover { color: var(--ink); text-decoration: underline; }
.footer-bottom { margin-top: var(--space-6); padding-top: var(--space-5); border-top: 1px solid var(--line); display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-3); }
@media (max-width: 640px) { .footer-grid { grid-template-columns: 1fr 1fr; } .footer-grid > :first-child { grid-column: 1 / -1; } }

/* ---------- Prose pages (privacy, terms, support) ---------- */
.prose { max-width: 780px; margin-inline: auto; padding: var(--space-7) var(--gutter) var(--space-8); }
.prose h1 { font-size: var(--step-3); font-weight: 750; margin-bottom: var(--space-2); }
.prose h2 { font-size: var(--step-2); font-weight: 700; margin: var(--space-7) 0 var(--space-3); }
.prose h3 { font-size: var(--step-1); font-weight: 650; margin: var(--space-5) 0 var(--space-2); letter-spacing: -0.015em; }
.prose p, .prose ul, .prose ol, .prose .table-wrap { margin-bottom: var(--space-4); }
.prose ul, .prose ol { padding-left: 1.3rem; }
.prose li { margin-bottom: 0.4rem; }
.prose li::marker { color: var(--text-2); }
.last-updated { color: var(--text-2); font-size: var(--step--1); margin-bottom: var(--space-6); }
.lead { font-size: var(--step-1); color: var(--text-2); line-height: 1.55; }
.toc { background: var(--bg-alt); border: 1px solid var(--line); border-radius: var(--r-card); padding: var(--space-5); margin: var(--space-5) 0 var(--space-6); }
.prose .toc h2 { margin: 0 0 var(--space-2); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-2); }
.toc ol { margin: 0; columns: 2 15rem; column-gap: var(--space-6); }
.callout { background: var(--brand-soft); border: 1px solid color-mix(in srgb, var(--brand) 25%, transparent); border-radius: var(--r-card); padding: var(--space-4) var(--space-5); margin: var(--space-5) 0; }
.callout p:last-child { margin-bottom: 0; }
.placeholder { background: var(--warning-bg); border: 1px dashed var(--warning-line); border-radius: 4px; padding: 0 0.25rem; font-weight: 600; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--r-card); }
.prose table { width: 100%; border-collapse: collapse; font-size: 0.94rem; }
.prose th, .prose td { text-align: left; vertical-align: top; padding: 0.75rem 0.9rem; border-bottom: 1px solid var(--line); }
.prose tr:last-child td { border-bottom: 0; }
.prose th { background: var(--bg-alt); font-weight: 650; }
.contact-card { background: var(--bg-alt); border: 1px solid var(--line); border-radius: var(--r-card); padding: var(--space-5); margin-top: var(--space-6); }

/* FAQ accordions (support page and homepage) */
.faq-list { display: grid; gap: var(--space-3); }
details.faq, .prose details {
    border: 1px solid var(--line); border-radius: 16px; background: var(--surface);
    padding: 0 var(--space-5); margin-bottom: var(--space-3); transition: box-shadow 0.25s, border-color 0.25s;
}
details.faq { margin-bottom: 0; }
details.faq[open], .prose details[open] { box-shadow: var(--shadow-2); border-color: transparent; }
details.faq summary, .prose details summary {
    list-style: none; cursor: pointer; padding: var(--space-4) 0; font-weight: 600; font-size: var(--step-0);
    display: flex; justify-content: space-between; align-items: center; gap: var(--space-4);
}
details summary::-webkit-details-marker { display: none; }
details.faq summary::after, .prose details summary::after {
    content: ""; flex: none; width: 10px; height: 10px; margin-right: 4px;
    border-right: 2px solid var(--text-2); border-bottom: 2px solid var(--text-2);
    transform: rotate(45deg) translateY(-3px); transition: transform 0.25s var(--ease);
}
details[open].faq summary::after, .prose details[open] summary::after { transform: rotate(225deg) translateY(-2px); }
details.faq > :not(summary), .prose details > :not(summary) { padding-bottom: var(--space-4); color: var(--text-2); margin: 0; }

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; }
}
.nav-links a[aria-current="page"] { color: var(--ink); background: var(--bg-alt); }
.nav-menu-cta { display: none; }
@media (max-width: 880px) {
    .nav-menu-cta { display: block; padding-top: var(--space-4); }
    .nav-links .nav-menu-cta a { border: 0; color: var(--on-brand); text-align: center; border-radius: var(--r-button); }
    .nav-links .nav-menu-cta a:hover { background: var(--brand-hover); color: var(--on-brand); }
}