:root {
  color-scheme: light;
  --ink: #17202b;
  --muted: #465463;
  --blue: #1255b0;
  --blue-dark: #103f85;
  --pale: #eef5ff;
  --line: #dce3eb;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "SamsungOne", "Malgun Gothic", sans-serif;
  font-size: 100%;
}
* { box-sizing: border-box; }
body { margin: 0; background: #f5f7fa; color: var(--ink); }
[hidden] { display: none !important; }
.page { max-width: 600px; min-height: 100vh; min-height: 100svh; margin: 0 auto; padding: 28px 24px 36px; background: #fff; overflow-wrap: anywhere; word-break: keep-all; }
h1, h2, p, figure { margin: 0; }
h1 { font-size: 2rem; line-height: 1.35; letter-spacing: -.035em; font-weight: 750; }
h2 { display: flex; align-items: center; gap: 12px; font-size: 1.75rem; line-height: 1.3; letter-spacing: -.035em; }
p { font-size: 1.375rem; line-height: 1.6; letter-spacing: -.025em; }
p + p { margin-top: 16px; }
b, strong { font-weight: 750; }
strong { color: var(--blue-dark); }
.intro { padding-bottom: 28px; border-bottom: 2px solid var(--ink); }
.intro p { margin-top: 10px; color: var(--muted); font-size: 1.3125rem; line-height: 1.5; }
.step { padding: 36px 0; border-bottom: 1px solid var(--line); }
.first-step { padding-top: 28px; }
.step-number { display: grid; place-items: center; flex: 0 0 38px; height: 38px; border-radius: 50%; font-size: 1.5rem; color: #fff; background: var(--blue); }
.instruction { margin-top: 20px; font-size: 1.5rem; line-height: 1.65; }
.short-press { margin-top: 18px; padding-left: 15px; border-left: 4px solid var(--blue); color: var(--muted); line-height: 1.5; }
.button-diagram { margin-top: 24px; }
svg { display: block; width: 100%; max-width: 360px; height: auto; margin: 0 auto; font-family: inherit; }
figcaption { color: var(--muted); font-size: 1.3125rem; line-height: 1.5; text-align: center; margin-top: 10px; }
.capture-example { margin-top: 22px; }
.capture-example svg { max-width: 328px; }
.gallery-tip { padding: 18px; background: var(--pale); border-left: 4px solid var(--blue); }
.practice-entry { padding: 28px 0 24px; }
button { font-family: inherit; cursor: pointer; -webkit-tap-highlight-color: transparent; overflow-wrap: anywhere; word-break: keep-all; }
.primary-button { display: block; width: 100%; min-height: 72px; border: 0; border-radius: 12px; padding: 18px 14px; background: var(--blue); color: white; font-size: 1.625rem; font-weight: 750; line-height: 1.4; letter-spacing: -.03em; }
.primary-button:active { background: var(--blue-dark); transform: translateY(1px); }
.primary-button:hover { background: var(--blue-dark); }
:focus-visible { outline: 3px solid #111; outline-offset: 5px; }
h1:focus { outline: none; }
.fallback { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
summary { cursor: pointer; min-height: 72px; padding: 21px 0; font-size: 1.375rem; line-height: 1.45; font-weight: 700; }
summary::marker { color: var(--blue); }
.fallback-content { padding: 0 0 24px; }
.fallback-content p { color: var(--muted); }
.practice-view, .complete-view { padding-top: 16px; text-align: center; }
.practice-keys { margin: 30px 0 26px; padding: 22px 12px; border-top: 2px solid var(--blue); border-bottom: 2px solid var(--blue); color: var(--blue-dark); }
.practice-keys p { font-size: 1.75rem; line-height: 1.45; font-weight: 750; }
.practice-keys p span { display: block; }
.practice-keys .plus { display: block; font-size: 2rem; line-height: 1; margin: 13px 0; }
.practice-prompt { font-size: 1.5rem; line-height: 1.55; margin-bottom: 30px; }
.text-button { display: block; background: transparent; color: var(--blue-dark); border: 0; min-height: 64px; padding: 16px 8px; width: 100%; font-size: 1.375rem; line-height: 1.45; text-decoration: underline; text-underline-offset: 5px; margin-top: 12px; }
.complete-mark { width: 64px; height: 64px; margin: 4px auto 24px; display: grid; place-items: center; border-radius: 50%; color: var(--blue); background: var(--pale); font-size: 2.5rem; font-weight: 700; }
.complete-view h1 { margin-bottom: 24px; }
.complete-view p { font-size: 1.5rem; line-height: 1.65; }
.complete-view .gallery-tip { margin-top: 28px; font-size: 1.375rem; }
.thumb { white-space: nowrap; }
@keyframes soft-flash { 0%,100% { opacity: 0; } 40% { opacity: .78; } }
@keyframes show-preview { from { opacity: .2; } to { opacity: 1; } }
@keyframes key-press { 0%,100% { fill: #1255b0; } 50% { fill: #081f45; } }
.demonstrate .screen-flash { animation: soft-flash 300ms ease-out 1; }
.demonstrate .mini-preview { animation: show-preview 400ms ease-out 1; }
.demonstrate .press-key { animation: key-press 400ms ease-out 1; }
@media (max-width: 359px) {
  .page { padding: 24px 16px 28px; }
  h1 { font-size: 1.875rem; }
  .instruction { font-size: 1.5rem; }
  .wide-break { display: none; }
}
@media (max-width: 299px) {
  .page { padding: 20px 10px 24px; }
  h1 { font-size: 1.625rem; }
  h2 { font-size: 1.5rem; }
  p, .intro p, figcaption, summary { font-size: 1.1875rem; }
  .instruction, .practice-prompt, .complete-view p { font-size: 1.3125rem; }
  .primary-button { font-size: 1.375rem; min-height: 68px; }
  .practice-keys p { font-size: 1.5rem; }
  .gallery-tip { padding: 14px 10px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .primary-button:active { transform: none; }
}

/* Official Samsung photographs, with HTML labels kept large and selectable. */
.photo-frame { position: relative; margin: 0 auto; }
.photo-frame img { display: block; width: 100%; height: auto; border-radius: 12px; }
.button-photo { max-width: 420px; }
.result-photo { max-width: 330px; }
.photo-label { position: absolute; right: 32%; max-width: 64%; padding: 5px 8px; color: #103f85; background: #fff; border: 2px solid #1255b0; border-radius: 6px; font-size: 21px; line-height: 1.35; font-weight: 750; transform: translateY(-50%); text-align: center; }
.photo-label::after { content: ""; position: absolute; width: 12%; min-width: 14px; height: 2px; background: #1255b0; top: 50%; left: 100%; }
.volume-label { top: 42%; }
.side-label { top: 75%; }
.photo-flash { position: absolute; inset: 0; background: white; opacity: 0; pointer-events: none; border-radius: 12px; }
.demonstrate .photo-flash { animation: soft-flash 300ms ease-out 1; }
.source-link { color: var(--blue-dark); text-underline-offset: 4px; }
@media (max-width: 299px) { .photo-label { font-size: 17px; padding: 4px 5px; } }