/* simplevolume.com — Night (default) and Light themes */
:root, [data-theme="dark"] {
  --bg: #0E121A; --panel: #131824; --panel-2: #161B26; --line: #1E2433; --line-2: #2A3142;
  --text: #E6EAF2; --muted: #A3ADC2; --link: #8CC8FF; --link-hover: #FFFFFF;
  --blue: #2196F3; --btn: #2196F3; --btn-text: #0E121A; --focus: #8CC8FF;
  --why-bg: #0F1D30; --code-bg: #0B0F16;
}
[data-theme="light"] {
  --bg: #F4F8FF; --panel: #FFFFFF; --panel-2: #F7F9FD; --line: #E3E8F2; --line-2: #CFD6E3;
  --text: #10203A; --muted: #4A5568; --link: #1565C0; --link-hover: #0D47A1;
  --blue: #2196F3; --btn: #1565C0; --btn-text: #FFFFFF; --focus: #1565C0;
  --why-bg: #EAF3FE; --code-bg: #F0F4FA;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body { margin: 0; background: var(--bg); color: var(--text); font: 17px/1.6 "IBM Plex Sans", system-ui, sans-serif; -webkit-font-smoothing: antialiased; }
a { color: var(--link); } a:hover { color: var(--link-hover); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.skip { position: absolute; left: -999px; } .skip:focus { left: 12px; top: 12px; background: var(--panel); padding: 8px 12px; z-index: 10; }
h1, h2, h3 { line-height: 1.12; letter-spacing: -0.02em; margin: 0; }
h2 { font-size: clamp(28px, 4vw, 38px); }
.sub { color: var(--muted); margin: 10px 0 22px; max-width: 720px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; }
.cap, .note { color: var(--muted); font-size: 14px; margin: 10px 4px 0; }
.block { padding-top: 88px; }

/* header */
.top { position: sticky; top: 0; z-index: 5; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.top-in { display: flex; align-items: center; gap: 24px; height: 64px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font: 600 20px "IBM Plex Mono", ui-monospace, monospace; color: var(--text); text-decoration: none; }
.logo-bar { width: 10px; height: 22px; border-radius: 2px; background: var(--blue); display: inline-block; }
.nav { display: flex; gap: 26px; margin-left: auto; font: 15px "IBM Plex Mono", ui-monospace, monospace; }
.nav a { color: var(--muted); text-decoration: none; } .nav a:hover { color: var(--text); }
.theme { font: 500 14px "IBM Plex Mono", ui-monospace, monospace; color: var(--text); background: transparent; border: 1px solid var(--line-2); border-radius: 8px; padding: 0 14px; min-height: 40px; cursor: pointer; }
@media (max-width: 640px) { .nav { display: none; } .theme { margin-left: auto; } }

/* hero */
.hero { padding-top: 72px; text-align: center; }
.kicker { font: 14px "IBM Plex Mono", ui-monospace, monospace; letter-spacing: 0.06em; text-transform: uppercase; color: var(--link); margin: 0; }
.hero h1 { font-size: clamp(38px, 6.4vw, 68px); max-width: 920px; margin: 18px auto 0; }
.hl { color: var(--blue); }
.lede { color: var(--muted); font-size: clamp(17px, 2vw, 20px); max-width: 660px; margin: 20px auto 0; }
.ctas { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 30px; }
.btn { display: inline-flex; align-items: center; min-height: 48px; padding: 0 24px; border-radius: 10px; font-weight: 600; text-decoration: none; color: var(--text); border: 1px solid var(--line-2); }
.btn.primary { background: var(--btn); color: var(--btn-text); border-color: var(--btn); }
.btn.primary:hover { color: var(--btn-text); filter: brightness(1.08); }
.hero-chart { margin-top: 52px; padding: 22px; }
#heroChart { width: 100%; height: 240px; display: block; }

/* colours */
.chips { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; margin-bottom: 14px; }
.chip { text-align: left; display: flex; gap: 12px; align-items: flex-start; padding: 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--panel); color: var(--text); font: inherit; cursor: pointer; min-height: 44px; }
.chip[aria-pressed="true"] { border-color: var(--text); background: var(--panel-2); }
.chip .sw { flex: none; width: 12px; height: 34px; border-radius: 3px; margin-top: 2px; }
.chip b { display: block; font-size: 16px; } .chip span.d { display: block; font-size: 13px; line-height: 1.4; color: var(--muted); margin-top: 2px; }
@media (max-width: 860px) { .chips { grid-template-columns: 1fr 1fr; } }
#colours .card { padding: 18px; }
.chart-mid { width: 100%; height: 220px; display: block; }

/* playground */
.pickers { display: flex; gap: 12px; flex-wrap: wrap; justify-content: space-between; margin-bottom: 14px; }
.seg { display: inline-flex; flex-wrap: wrap; gap: 6px; }
.seg button { font: 500 14px "IBM Plex Sans", sans-serif; color: var(--muted); background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 0 14px; min-height: 40px; cursor: pointer; }
.seg button[aria-pressed="true"] { color: var(--text); border-color: var(--blue); background: var(--panel-2); }
.seg button:disabled { opacity: 0.4; cursor: default; }
.seg button small { display: block; font-size: 11px; color: var(--muted); font-weight: 400; line-height: 1.2; }
.play { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 18px; align-items: start; }
@media (max-width: 980px) { .play { grid-template-columns: 1fr; } }
.chart-card { position: relative; padding: 10px; overflow: hidden; }
.chart-big { width: 100%; height: clamp(380px, 56vw, 560px); display: block; cursor: crosshair; touch-action: manipulation; }
.legend { position: absolute; left: 18px; top: 12px; font: 12px "IBM Plex Mono", ui-monospace, monospace; color: var(--muted); pointer-events: none; z-index: 1; background: color-mix(in srgb, var(--panel) 70%, transparent); padding: 2px 4px; border-radius: 4px; }
.legend b { color: var(--text); font-weight: 600; }
.svtable { position: absolute; right: 74px; z-index: 1; display: flex; gap: 3px; pointer-events: auto; }
.svtable.vertical { flex-direction: column; }
.svtable .cell { font: 12px "IBM Plex Sans", sans-serif; padding: 3px 8px; white-space: nowrap; cursor: help; }
.svtable.plain { gap: 0; border: 1px solid; }
.svtable.plain .cell { border: 1px solid; }
.why { margin-top: 14px; border: 1px solid var(--blue); background: var(--why-bg); border-radius: 12px; padding: 18px 20px; min-height: 120px; }
.why .meta { font: 12px "IBM Plex Mono", ui-monospace, monospace; color: var(--link); letter-spacing: 0.04em; }
.why h3 { font-size: 22px; margin: 8px 0 0; display: flex; gap: 10px; align-items: center; }
.why h3 .sw { width: 12px; height: 22px; border-radius: 3px; flex: none; }
.why p { margin: 8px 0 0; }
.why .extra { color: var(--muted); font-size: 15px; }

.settings { padding: 18px; max-height: calc(100vh - 100px); overflow: auto; position: sticky; top: 80px; }
@media (max-width: 980px) { .settings { position: static; max-height: none; } }
.settings-head { display: flex; justify-content: space-between; align-items: baseline; }
.settings h3 { font-size: 18px; }
.hint { color: var(--muted); font-size: 13px; margin: 4px 0 10px; }
.link-btn { font: 13px "IBM Plex Sans", sans-serif; background: none; border: none; color: var(--link); cursor: pointer; padding: 8px 0; min-height: 36px; }
fieldset { border: none; border-top: 1px solid var(--line); margin: 0; padding: 12px 0 8px; }
legend { font: 600 12px "IBM Plex Mono", ui-monospace, monospace; letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); padding: 0 6px 0 0; }
.row { display: grid; grid-template-columns: 1fr auto; gap: 4px 10px; align-items: center; padding: 6px 0; }
.row label { font-size: 14px; line-height: 1.35; }
.row .help { grid-column: 1 / -1; font-size: 12.5px; line-height: 1.45; color: var(--muted); }
.row.sub-row { padding-left: 14px; }
.row select, .row input[type="number"] { font: 14px "IBM Plex Sans", sans-serif; color: var(--text); background: var(--panel-2); border: 1px solid var(--line-2); border-radius: 6px; padding: 6px 8px; min-height: 36px; max-width: 170px; }
.row input[type="number"] { width: 84px; }
.row input[type="checkbox"] { width: 20px; height: 20px; accent-color: var(--blue); }
.row.off { opacity: 0.5; }

/* MA note */
.ma-card { padding: 34px 36px; max-width: 860px; }
.ma-card p { color: var(--muted); font-size: 18px; margin: 14px 0 0; }
.ma-card .sig { color: var(--text); font-family: "IBM Plex Mono", monospace; font-size: 15px; }

/* alerts */
.steps { padding-left: 22px; max-width: 820px; margin: 18px 0 0; }
.steps li { margin: 0 0 12px; padding-left: 6px; }
kbd { font: 13px "IBM Plex Mono", monospace; border: 1px solid var(--line-2); border-bottom-width: 2px; border-radius: 4px; padding: 1px 6px; background: var(--panel); }
.msg { background: var(--code-bg); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; font: 14px/1.6 "IBM Plex Mono", ui-monospace, monospace; white-space: pre-wrap; max-width: 820px; overflow-x: auto; }

/* faq */
.faq { max-width: 860px; margin-top: 18px; }
.faq details { border-top: 1px solid var(--line); padding: 4px 0; }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; font-weight: 600; font-size: 18px; padding: 14px 0; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: "IBM Plex Mono", monospace; color: var(--muted); }
.faq details[open] summary::after { content: "−"; }
.faq .ans { color: var(--muted); padding: 0 0 16px; }
.faq .ans p { margin: 0 0 10px; } .faq .ans ul { margin: 0 0 10px; padding-left: 20px; }

/* footer */
.foot { margin-top: 110px; border-top: 1px solid var(--line); padding: 40px 0 30px; }
.foot-in { display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.foot p { color: var(--muted); margin: 10px 0 0; font-size: 15px; }
.links { list-style: none; margin: 0; padding: 0; display: flex; gap: 22px; flex-wrap: wrap; font-family: "IBM Plex Mono", monospace; font-size: 15px; }
.links a { display: inline-block; padding: 8px 0; }
.fine { color: var(--muted); font-size: 13px; margin-top: 26px; }
.show-settings { display: none; }
@media (max-width: 980px) {
  .show-settings { display: inline; margin-left: auto; margin-right: 14px; }
  .settings:not(.open) #settingsBody { display: none; }
}