:root {
  --bg: #16181D; --surface: #22252C; --raised: #2A2E36;
  --text: #E6E6E6; --muted: #8A8F99; --line: #343841;
  --ok: #4CC38A; --high: #F2B33D; --low: #EF5350; --stale: #777B84;
  --blue: #4FA3F7; --accent: #4FA3F7;
  --soft: #c4c7ce; --on-accent: #0d1620; --grid: #2F333B; --page-bg: #101216;
  --big-bg: #000; --overlay-btn: rgba(255,255,255,.16);
  --toast-err: #5a2626;
  --banner-bg: #3a2f17; --banner-bd: #6b5420; --banner-fg: #F2B33D;
  --err-bg: #3a1d1d; --err-bd: #6b2a2a; --err-fg: #f3a3a1;
  color-scheme: dark;
  --tabbar-h: 0px;
  --sat: env(safe-area-inset-top, 0px); --sab: env(safe-area-inset-bottom, 0px);
  --sal: env(safe-area-inset-left, 0px); --sar: env(safe-area-inset-right, 0px);
}
/* Theme: dark is the default; "light" is forced with data-theme, and with no data-theme
   (Auto) the device's own light/dark setting decides. theme.js sets data-theme before first paint. */
:root[data-theme="light"] {
  --bg: #F4F5F7; --surface: #FFFFFF; --raised: #EEF0F3;
  --text: #1B1E24; --muted: #5F6672; --line: #D9DCE2;
  --ok: #17935A; --high: #B86E00; --low: #D6372F; --stale: #8A8F99;
  --blue: #1F6FD6; --accent: #1F6FD6;
  --soft: #3C424D; --on-accent: #FFFFFF; --grid: #E3E5EA; --page-bg: #E9EBEF;
  --big-bg: #FFFFFF; --overlay-btn: rgba(0,0,0,.08);
  --toast-err: #F9D6D3;
  --banner-bg: #FFF4DB; --banner-bd: #E8C777; --banner-fg: #8A5200;
  --err-bg: #FDE3E1; --err-bd: #F0B3AE; --err-fg: #A32B24;
  color-scheme: light;
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #F4F5F7; --surface: #FFFFFF; --raised: #EEF0F3;
    --text: #1B1E24; --muted: #5F6672; --line: #D9DCE2;
    --ok: #17935A; --high: #B86E00; --low: #D6372F; --stale: #8A8F99;
    --blue: #1F6FD6; --accent: #1F6FD6;
    --soft: #3C424D; --on-accent: #FFFFFF; --grid: #E3E5EA; --page-bg: #E9EBEF;
    --big-bg: #FFFFFF; --overlay-btn: rgba(0,0,0,.08);
    --toast-err: #F9D6D3;
    --banner-bg: #FFF4DB; --banner-bd: #E8C777; --banner-fg: #8A5200;
    --err-bg: #FDE3E1; --err-bd: #F0B3AE; --err-fg: #A32B24;
    color-scheme: light;
  }
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
[hidden] { display: none !important; }
html { background: var(--bg); }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.4 -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-text-size-adjust: 100%;
}
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
h1, h2, h3, h4, p { margin: 0; }
a { color: var(--accent); }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.center { text-align: center; }

#app { max-width: 520px; margin: 0 auto; min-height: 100vh; min-height: 100dvh; }
.view {
  padding: calc(var(--sat) + 12px) calc(var(--sar) + 16px)
           calc(var(--tabbar-h) + var(--sab) + 24px) calc(var(--sal) + 16px);
}
.page-title { font-size: 26px; margin: 4px 0 14px; }

/* Cards, fields, buttons */
.card { background: var(--surface); border-radius: 16px; padding: 16px; margin-bottom: 14px; }
.card h3 { font-size: 17px; margin-bottom: 8px; }
.card > p + .field, .card > h3 + .field { margin-top: 10px; }
.field { display: block; font-size: 13px; color: var(--muted); margin-top: 12px; }
.field:first-child { margin-top: 0; }
.two > .field { margin-top: 12px; }
input, select {
  font: inherit; font-size: 16px; color: var(--text);
  background: var(--raised); border: 1px solid transparent; border-radius: 10px;
  padding: 0 12px; min-height: 44px; width: 100%; margin-top: 4px;
  appearance: none; -webkit-appearance: none; outline: none;
}
select {
  padding-right: 32px;
  background-image: linear-gradient(45deg, transparent 50%, var(--muted) 50%), linear-gradient(135deg, var(--muted) 50%, transparent 50%);
  background-position: calc(100% - 18px) 50%, calc(100% - 13px) 50%;
  background-size: 5px 5px; background-repeat: no-repeat;
}
input:focus, select:focus { border-color: var(--accent); }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.check { display: flex; align-items: center; gap: 10px; margin-top: 14px; min-height: 44px; font-size: 15px; }
.check input { width: 22px; height: 22px; min-height: 0; margin: 0; flex: none; appearance: auto; -webkit-appearance: checkbox; accent-color: var(--accent); }
.btn {
  min-height: 46px; padding: 0 18px; border-radius: 12px;
  background: var(--raised); font-weight: 600;
}
.btn.primary { background: var(--accent); color: var(--on-accent); }
.btn.danger { color: var(--low); }
.btn.block { display: block; width: 100%; margin-top: 12px; }
.btn:disabled { opacity: .5; }
.icon-btn { width: 44px; height: 44px; display: grid; place-items: center; color: var(--muted); border-radius: 22px; }
.msg { font-size: 14px; }
.msg.error { color: var(--low); margin-top: 8px; }
.msg:empty { display: none; }

/* Auth */
.auth { min-height: 100vh; min-height: 100dvh; padding: 16px 16px 48px; }
.auth-card { width: 100%; max-width: 380px; margin: 4vh auto 0; }
.nojs { padding: 24px; max-width: 520px; margin: 0 auto; color: var(--text); }

/* What signed-out visitors read under the sign-in form */
.landing { max-width: 520px; margin: 40px auto 0; color: var(--soft); font-size: 15px; line-height: 1.55; }
.landing h2 { font-size: 24px; line-height: 1.2; color: var(--text); margin-bottom: 10px; }
.landing h3 { font-size: 17px; color: var(--text); margin: 24px 0 6px; }
.landing b { color: var(--text); }
.features { margin: 14px 0 0; padding-left: 20px; }
.features li { margin-top: 8px; }
.shots { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: center; gap: 16px; margin: 24px 0 4px; }
.shots figure { margin: 0; text-align: center; max-width: 100%; }
.shots img { max-width: 100%; height: auto; border-radius: 14px; border: 1px solid var(--line); display: block; }
.shots figcaption { font-size: 12px; color: var(--muted); margin-top: 6px; }
.landing .foot { margin-top: 28px; text-align: center; }
.auth-logo { display: block; margin: 0 auto 8px; border-radius: 14px; }
.auth-card h1 { text-align: center; font-size: 24px; }
.auth-card > p.muted { text-align: center; margin: 6px 0 14px; font-size: 14px; }
.auth-card .legal { text-align: center; margin-top: 14px; }

/* Home */
.banner { background: var(--banner-bg); border: 1px solid var(--banner-bd); color: var(--banner-fg); padding: 12px 14px; border-radius: 12px; margin-bottom: 12px; font-size: 14px; display: flex; gap: 10px; align-items: center; justify-content: space-between; }
.banner.err { background: var(--err-bg); border-color: var(--err-bd); color: var(--err-fg); }
.banner button { color: var(--accent); font-weight: 600; min-height: 44px; white-space: nowrap; }
.glucose-card { position: relative; text-align: center; padding: 14px 12px 16px; }
.card-tools { position: absolute; top: 6px; right: 6px; display: flex; }
.refresh.spin svg { animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.big-reading { display: inline-flex; align-items: baseline; justify-content: center; min-height: 44px; max-width: 100%; padding: 0 8px; line-height: 1; }
.gval { font-size: 104px; font-weight: 700; letter-spacing: -2px; font-variant-numeric: tabular-nums; }
.gval.word { font-size: 80px; letter-spacing: 0; }
.garrow { font-size: 56px; margin-left: 6px; font-weight: 600; }
.ok { color: var(--ok); } .high { color: var(--high); } .low { color: var(--low); }
.stale { color: var(--stale); }
.gval.stale { text-decoration: line-through; }
.gmeta { color: var(--muted); font-size: 15px; margin-top: 6px; }
.gmeta b { color: var(--text); font-weight: 600; }
.chart-card { padding: 10px 10px 8px; }
.chart svg { display: block; }
.seg { display: flex; gap: 4px; background: var(--bg); border-radius: 10px; padding: 3px; margin: 0 0 8px; }
.seg button { flex: 1; min-height: 38px; border-radius: 8px; color: var(--muted); font-weight: 600; font-size: 15px; }
.seg button.active { background: var(--raised); color: var(--text); }

/* Settings */
.card .muted.small { margin-top: 8px; }
.about { margin-top: 10px; color: var(--soft); }
.about b { color: var(--text); }
.about-h { font-size: 14px; margin: 16px 0 0; }
.steps { margin: 8px 0 0; padding-left: 20px; }
.steps li { margin-top: 6px; }
.links { margin-top: 14px; }
.stored { margin: 10px 0 0; padding: 12px; background: var(--raised); border-radius: 10px; font: 12px/1.5 ui-monospace, Consolas, monospace; white-space: pre-wrap; overflow-wrap: anywhere; color: var(--soft); }


/* Big mode */
.big { position: fixed; inset: 0; z-index: 50; background: var(--big-bg); display: flex; flex-direction: column; align-items: center; justify-content: center; padding: var(--sat) var(--sar) var(--sab) var(--sal); text-align: center; cursor: pointer; }
.big-main { --n: 3; display: flex; align-items: baseline; justify-content: center; line-height: 1; font-weight: 700; font-size: min(calc(90vw / (var(--n) * 0.58 + 0.7)), 52vh); white-space: nowrap; }
.big-main.word { font-size: min(calc(90vw / (var(--n) * 0.66 + 0.2)), 52vh); }
#bigArrow { margin-left: .06em; font-weight: 600; }
.big-main.stale #bigVal { text-decoration: line-through; }
.big-info { margin-top: 3vh; font-size: clamp(16px, min(4.2vw, 5vh), 30px); color: var(--muted); padding: 0 12px; }
.big-info b { color: var(--text); font-weight: 600; }

.big-bar { position: absolute; left: 0; right: 0; bottom: calc(var(--sab) + 18px); display: flex; justify-content: center; gap: 12px; cursor: default; }
.big-bar .btn { min-width: 130px; background: var(--overlay-btn); color: var(--text); }
.tips { margin-top: 10px; color: var(--soft); }
.tips summary { cursor: pointer; color: var(--accent); min-height: 32px; }
.tips ul { margin: 8px 0 0; padding-left: 18px; }
.tips li { margin-top: 8px; }
.tips b { color: var(--text); }

/* Landscape: the big number can use far more of the screen. */
@media (orientation: landscape) {
  .big-main { font-size: min(calc(90vw / (var(--n) * 0.58 + 0.7)), 66vh); }
  .big-main.word { font-size: min(calc(90vw / (var(--n) * 0.66 + 0.2)), 66vh); }
  .big-info { margin-top: 2vh; font-size: clamp(14px, 5vh, 28px); }
}

/* A phone on its side: reading on the left, chart on the right. */
@media (orientation: landscape) and (max-height: 600px) {
  #app { max-width: none; }
  .view { padding-top: calc(var(--sat) + 8px); }
  #view-home { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 0 12px; align-content: start; }
  #view-home .banner { grid-column: 1 / -1; }
  #view-home .card { margin-bottom: 0; }
  .glucose-card { display: flex; flex-direction: column; align-items: center; justify-content: center; }
  .gval { font-size: min(104px, 30vh); }
  .gval.word { font-size: min(80px, 24vh); }
  .garrow { font-size: min(56px, 17vh); }
  #view-settings, #view-about { max-width: 640px; margin: 0 auto; }
}

.toast { position: fixed; left: 50%; bottom: calc(var(--tabbar-h) + var(--sab) + 24px); transform: translate(-50%, 20px); background: var(--raised); color: var(--text); padding: 10px 18px; border-radius: 22px; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; z-index: 60; box-shadow: 0 6px 20px rgba(0,0,0,.5); font-weight: 600; max-width: 90vw; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast.error { background: var(--toast-err); }

@media (min-width: 560px) {
  body { background: var(--page-bg); }
  #app { background: var(--bg); box-shadow: 0 0 0 1px var(--line); }
}

/* Chart (classes used by chart.js) */
.c-band { fill: var(--ok); }
.c-grid { stroke: var(--grid); }
.c-lbl { fill: var(--muted); }
.c-low-line { stroke: var(--low); }
.c-high-line { stroke: var(--high); }
.c-ok { fill: var(--ok); } .c-high { fill: var(--high); } .c-low { fill: var(--low); }

/* Desktop and tablet landscape: use the whole window like a desktop app. */
@media (min-width: 900px) and (min-height: 600px) {
  body { background: var(--bg); }
  #app { max-width: none; box-shadow: none; background: transparent; }
  .view { padding: 24px 28px; }


  /* Home: reading on the left, chart filling the rest */
  #view-home {
    height: 100vh; height: 100dvh; box-sizing: border-box;
    display: grid; grid-template-columns: minmax(320px, 2fr) 3fr; grid-template-rows: auto minmax(0, 1fr); gap: 20px;
  }
  #view-home .banner { grid-column: 1 / -1; grid-row: 1; margin: 0; }
  #view-home .glucose-card, #view-home .chart-card { grid-row: 2; margin: 0; min-height: 0; }
  .glucose-card { container-type: inline-size; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 20px 16px; }
  .gval { font-size: 120px; font-size: min(32cqw, 30vh); }
  .gval.word { font-size: 90px; font-size: min(24cqw, 22vh); }
  .garrow { font-size: 64px; font-size: min(18cqw, 17vh); }
  .gmeta { font-size: 18px; margin-top: 14px; }
  .big-reading { padding: 0; }
  .card-tools { top: 12px; right: 12px; }
  .chart-card { display: flex; flex-direction: column; padding: 16px 18px 14px; }
  .chart { position: relative; flex: 1; min-height: 160px; }
  .chart svg { position: absolute; inset: 0; width: 100%; height: 100%; }
  .seg button { font-size: 16px; min-height: 42px; }

  /* Settings: cards flow into columns */
  #view-settings { column-width: 380px; column-gap: 20px; max-width: 1240px; margin: 0 auto; }
  #view-settings .page-title { column-span: all; }
  #view-settings .card { break-inside: avoid; }

  /* Signed-out page: explanation on the left, sign-in on the right */
  .auth { display: grid; grid-template-columns: minmax(0, 560px) minmax(340px, 400px); gap: 64px; justify-content: center; align-content: start; padding: 9vh 32px 64px; }
  .auth-card { grid-column: 2; grid-row: 1; margin: 0; align-self: start; position: sticky; top: 6vh; }
  .landing { grid-column: 1; grid-row: 1; margin: 0; max-width: none; }

  .toast { bottom: 28px; }
}

/* Chart view: a small reading in a header, and the graph takes the rest of the screen (like a CGM's own display).
   ID selectors so these win over the desktop and phone-landscape layouts above. */
#view-home.chart-focus {
  display: grid; grid-template-columns: minmax(0, 1fr); grid-template-rows: auto auto minmax(0, 1fr);
  gap: 12px; height: 100vh; height: 100dvh; box-sizing: border-box;
}
#view-home.chart-focus .banner { grid-column: 1; grid-row: 1; margin: 0; }
#view-home.chart-focus .glucose-card {
  grid-column: 1; grid-row: 2; margin: 0; min-height: 0; container-type: normal;
  display: flex; flex-direction: row; align-items: center; justify-content: flex-start; gap: 16px;
  text-align: left; padding: 10px 240px 10px 16px;
}
#view-home.chart-focus .chart-card { grid-column: 1; grid-row: 3; margin: 0; min-height: 0; display: flex; flex-direction: column; }
#view-home.chart-focus .chart { position: relative; flex: 1; min-height: 120px; }
#view-home.chart-focus .chart svg { position: absolute; inset: 0; width: 100%; height: 100%; }
#view-home.chart-focus .big-reading { flex: none; padding: 0; min-height: 0; }
#view-home.chart-focus .gval { font-size: clamp(44px, min(8vh, 13vw), 84px); letter-spacing: -1px; }
#view-home.chart-focus .gval.word { font-size: clamp(34px, min(6.5vh, 10vw), 66px); }
#view-home.chart-focus .garrow { font-size: clamp(26px, min(5vh, 8vw), 48px); margin-left: 4px; }
#view-home.chart-focus .gmeta { margin: 0; font-size: 15px; min-width: 0; overflow-wrap: anywhere; }
#view-home.chart-focus .card-tools { top: 50%; transform: translateY(-50%); }
@media (max-width: 600px) {
  #view-home.chart-focus .glucose-card { padding-right: 150px; gap: 10px; }
  #view-home.chart-focus .gmeta { font-size: 13px; }
}

/* Chart view on a narrow screen: number and buttons share the first row, the details go underneath. */
@media (max-width: 600px) {
  #view-home.chart-focus .glucose-card { flex-wrap: wrap; align-content: center; row-gap: 2px; padding: 8px 12px; }
  #view-home.chart-focus .gmeta { flex-basis: 100%; order: 3; }
  #view-home.chart-focus .card-tools { top: 4px; right: 4px; transform: none; }
}
/* Chart view on a phone on its side: every pixel of height goes to the graph. */
@media (orientation: landscape) and (max-height: 600px) {
  #view-home.chart-focus { gap: 8px; padding-top: calc(var(--sat) + 6px); padding-bottom: calc(var(--tabbar-h) + var(--sab) + 8px); }
  #view-home.chart-focus .glucose-card { padding-top: 4px; padding-bottom: 4px; }
  #view-home.chart-focus .chart-card { padding: 6px 8px 4px; }
  #view-home.chart-focus .seg { margin-bottom: 4px; }
  #view-home.chart-focus .seg button { min-height: 30px; }
}

/* Settings header with a close button; the icon cluster is slimmer on narrow screens (five buttons) */
.settings-head { display: flex; align-items: center; justify-content: space-between; margin: 4px 0 14px; }
.settings-head .page-title { margin: 0; }
@media (max-width: 600px) {
  .card-tools .icon-btn { width: 38px; height: 44px; }
}
@media (min-width: 900px) and (min-height: 600px) {
  .settings-head { column-span: all; }
}