/*
 * SPDX-License-Identifier: Apache-2.0
 * Copyright 2026 CLSOFTLAB (씨엘소프트랩), Dr. Lee Il-guk (이일국)
 *
 * High-contrast light and dark themes, 48 px minimum targets, works at 320 px width.
 * Colour is never the only signal: every state also has text and/or a shape.
 */

:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #000000;
  --muted: #2b2b2b;
  --card: #f2f2f2;
  --border: #000000;
  --accent: #0a3a8c;
  --accent-fg: #ffffff;
  --focus: #0a3a8c;
  --focus-halo: #ffd400;
  --danger: #a3001b;
  --danger-fg: #ffffff;
  --warn-bg: #fff3b0;
  --warn-fg: #000000;
  --ok: #0b6b2b;
  --radius: 0.5rem;
  --gap: 1rem;
  --target: 48px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --fg: #ffffff;
    --muted: #dcdcdc;
    --card: #141414;
    --border: #ffffff;
    --accent: #ffd400;
    --accent-fg: #000000;
    --focus: #ffd400;
    --focus-halo: #000000;
    --warn-bg: #3a3000;
    --warn-fg: #ffffff;
    --ok: #7ee2a0;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  font-size: 1.0625rem;
  line-height: 1.55;
  padding-inline: max(16px, env(safe-area-inset-left)) max(16px, env(safe-area-inset-right));
  overflow-wrap: anywhere;
}

img { max-width: 100%; height: auto; }

h1, h2, h3 { line-height: 1.25; margin: 0.5em 0 0.4em; }
h1 { font-size: 1.75rem; }
h2 { font-size: 1.3rem; }
p { margin: 0.5em 0; }

a { color: var(--accent); text-underline-offset: 0.15em; text-decoration-thickness: 0.1em; }
@media (prefers-color-scheme: dark) { a { color: var(--accent); } }

:focus-visible {
  outline: 4px solid var(--focus);
  outline-offset: 3px;
  box-shadow: 0 0 0 8px var(--focus-halo);
}
[tabindex="-1"]:focus { outline: none; box-shadow: none; }
[tabindex="-1"]:focus-visible { outline: 3px dashed var(--focus); outline-offset: 4px; box-shadow: none; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0; border: 0;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute; left: 16px; top: -100px; z-index: 10;
  background: var(--accent); color: var(--accent-fg);
  padding: 0.75rem 1rem; border-radius: var(--radius); font-weight: 700;
}
.skip-link:focus { top: 8px; }

/* ----- layout ------------------------------------------------------------------------------- */

.app-header, main, .app-footer { max-width: 42rem; margin-inline: auto; }

.app-header {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem 1rem;
  padding-block: 0.75rem;
  border-bottom: 2px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 0.5rem; font-weight: 800; font-size: 1.2rem; margin: 0; flex: 1 1 auto; }
.brand img { border-radius: 6px; }

.nav-list { display: flex; flex-wrap: wrap; gap: 0.5rem; list-style: none; margin: 0; padding: 0; }
.nav-btn {
  min-height: var(--target); min-width: var(--target);
  padding: 0.5rem 1rem; font: inherit; font-weight: 700;
  color: var(--fg); background: transparent;
  border: 2px solid var(--border); border-radius: var(--radius); cursor: pointer;
}
.nav-btn[aria-current="page"] { background: var(--fg); color: var(--bg); text-decoration: underline; text-underline-offset: 0.2em; }

.conn-pill {
  display: inline-flex; align-items: center; gap: 0.5rem; margin: 0;
  padding: 0.25rem 0.75rem; min-height: 36px;
  border: 2px solid var(--border); border-radius: 999px; font-weight: 700; font-size: 0.95rem;
}
.conn-dot { width: 0.9rem; height: 0.9rem; border-radius: 50%; border: 3px solid currentColor; flex: none; }
.conn-pill[data-state="connected"] .conn-dot { background: var(--ok); border-color: var(--ok); }
.conn-pill[data-state="connecting"] .conn-dot,
.conn-pill[data-state="reconnecting"] .conn-dot { border-style: dashed; border-radius: 2px; animation: spin 2s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

main { padding-block: 0.5rem 2rem; }
main:focus { outline: none; }

.app-footer {
  border-top: 2px solid var(--border);
  padding-block: 1rem 2rem;
  font-size: 0.95rem; color: var(--muted);
}
.app-footer a { display: inline-block; min-height: var(--target); padding-block: 0.6rem; }

.card {
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem 1rem;
  margin: 0 0 var(--gap);
}
.card > h2:first-child { margin-top: 0.1em; }

.stack { display: flex; flex-direction: column; gap: 0.75rem; margin: 1rem 0; }
.button-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr)); gap: 0.75rem; }

.note { font-weight: 600; }
.hint { color: var(--muted); font-size: 0.97rem; }
.big-text { font-size: 1.2rem; font-weight: 700; }
.error-text { color: var(--danger); font-weight: 700; margin: 0.25rem 0; }
.error-text:empty { margin: 0; } /* stays rendered: #connect-error is a role="alert" live region */
@media (prefers-color-scheme: dark) { .error-text { color: #ff8a8a; } }
.status-text { font-weight: 700; min-height: 1.5em; }

.notice {
  border: 3px solid var(--border); border-radius: var(--radius);
  padding: 0.75rem 1rem; margin: 0.75rem 0;
}
.notice-warn { background: var(--warn-bg); color: var(--warn-fg); border-left-width: 10px; }
.notice-title { font-size: 1.1rem; margin: 0 0 0.25rem; }

.badge-demo {
  display: inline-block; font-weight: 800; padding: 0.2rem 0.6rem;
  border: 2px dashed var(--border); border-radius: var(--radius);
}
.card-demo { border-style: dashed; }

/* ----- controls ----------------------------------------------------------------------------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  min-height: var(--target); min-width: var(--target);
  padding: 0.6rem 1.1rem;
  font: inherit; font-size: 1.1rem; font-weight: 700; line-height: 1.25; text-align: center;
  color: var(--fg); background: var(--bg);
  border: 2px solid var(--border); border-radius: var(--radius);
  cursor: pointer; text-decoration: none;
}
.btn:hover { text-decoration: underline; text-underline-offset: 0.2em; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.btn-big { width: 100%; min-height: 64px; font-size: 1.3rem; }
.btn-huge { width: 100%; min-height: 88px; font-size: 1.5rem; }
.btn-link { background: transparent; border-color: transparent; color: var(--accent); text-decoration: underline; padding-inline: 0; }
.btn[aria-disabled="true"] { border-style: dashed; opacity: 0.8; }
.btn[aria-pressed="true"] { background: var(--fg); color: var(--bg); }
.btn[aria-pressed="true"]::before { content: "✓ "; }
.btn[hidden] { display: none; }

label { display: block; font-weight: 700; margin: 0.9rem 0 0.3rem; }

select, input[type="tel"], input[type="text"] {
  display: block; width: 100%;
  min-height: var(--target);
  padding: 0.5rem 0.75rem;
  font: inherit; font-size: 1.1rem; /* >= 16px so iOS does not zoom */
  color: var(--fg); background: var(--bg);
  border: 2px solid var(--border); border-radius: var(--radius);
}
input[aria-invalid="true"] { border-width: 4px; border-color: var(--danger); }

.check {
  display: flex; align-items: center; gap: 0.75rem;
  min-height: var(--target); margin: 0.5rem 0; cursor: pointer; font-weight: 600;
}
.check input { width: 1.6rem; height: 1.6rem; flex: none; margin: 0; accent-color: var(--accent); }

.range-row { display: flex; align-items: center; gap: 1rem; }
.range-row input[type="range"] { flex: 1; min-width: 0; height: var(--target); accent-color: var(--accent); }
.range-row output { font-weight: 800; min-width: 3.5em; text-align: end; }

fieldset.card { min-width: 0; }
legend { font-size: 1.25rem; font-weight: 800; padding: 0 0.35rem; }
.radio-group { border: 0; padding: 0; margin: 1rem 0 0.5rem; min-width: 0; }
.radio-group legend { font-size: 1.05rem; padding: 0; }

.tips { margin: 1rem 0; border: 2px solid var(--border); border-radius: var(--radius); padding: 0 1rem; }
.tips summary { min-height: var(--target); display: flex; align-items: center; font-weight: 700; cursor: pointer; }
.tips summary::before { content: "▸"; margin-inline-end: 0.5rem; }
.tips[open] summary::before { content: "▾"; }
.tips summary::-webkit-details-marker { display: none; }

/* ----- status ------------------------------------------------------------------------------- */

.kv { margin: 0; }
.kv > div {
  display: grid; grid-template-columns: minmax(8rem, 40%) 1fr; gap: 0.25rem 1rem;
  padding: 0.45rem 0; border-top: 1px solid var(--muted);
}
.kv > div:first-child { border-top: 0; }
.kv dt { font-weight: 700; }
.kv dd { margin: 0; }
.fault-list { margin: 0; padding-inline-start: 1.2rem; font-weight: 700; }
.fault-list li::marker { content: "⚠ "; }
@media (max-width: 26rem) { .kv > div { grid-template-columns: 1fr; } }

/* ----- log ---------------------------------------------------------------------------------- */

.log { list-style: none; margin: 0.5rem 0 1rem; padding: 0; display: flex; flex-direction: column; gap: 0.5rem; }
.log-item {
  background: var(--bg); border: 2px solid var(--border); border-inline-start-width: 10px;
  border-radius: var(--radius); padding: 0.5rem 0.75rem;
}
.log-item p { margin: 0.1rem 0; }
.log-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.25rem 0.6rem; }
.log-text { font-size: 1.15rem; font-weight: 700; }
.log-meta { color: var(--muted); font-size: 0.95rem; }
.level-badge {
  display: inline-block; padding: 0.05rem 0.5rem; border-radius: 0.3rem;
  font-weight: 800; font-size: 0.95rem; border: 1px solid transparent;
  background: #4a4a4a; color: #ffffff;
}
.log-item[data-level="0"], .log-item[data-level="1"] { border-inline-start-color: var(--danger); }
.log-item[data-level="0"] .level-badge, .log-item[data-level="1"] .level-badge { background: var(--danger); color: var(--danger-fg); }
.log-item[data-level="2"] { border-inline-start-color: #b58900; }
.log-item[data-level="2"] .level-badge { background: #ffd400; color: #000000; }
.log-item[data-level="3"] .level-badge { background: #0a3a8c; color: #ffffff; }
.log-item[data-level="0"] { border-style: double; border-width: 4px; border-inline-start-width: 10px; }
@media (prefers-color-scheme: dark) {
  .log-item[data-level="0"], .log-item[data-level="1"] { border-inline-start-color: #ff5a5a; }
  .log-item[data-level="3"] .level-badge { background: #9cc3ff; color: #000000; }
  .level-badge { background: #d0d0d0; color: #000000; }
}

/* ----- SOS full-screen alert ---------------------------------------------------------------- */

dialog.sos {
  position: fixed; inset: 0;
  width: 100%; height: 100%; max-width: 100%; max-height: 100%;
  margin: 0; padding: 0; border: 0;
  overflow-y: auto;
  background: #8f0016; color: #ffffff;
}
dialog.sos::backdrop { background: #000000; }
dialog.sos[data-state="countdown"] { background: #ffd400; color: #000000; }
.sos-inner {
  max-width: 42rem; margin-inline: auto;
  padding: max(16px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) 2rem max(16px, env(safe-area-inset-left));
}
.sos h1 { font-size: 2.1rem; margin-top: 0.25rem; }
.sos h2 { font-size: 1.4rem; margin-top: 1.5rem; }
.sos-icon {
  display: inline-block; margin: 0.5rem 0 0; padding: 0.2rem 0.8rem;
  font-size: 1.5rem; font-weight: 900; letter-spacing: 0.1em;
  border: 4px solid currentColor; border-radius: var(--radius);
}
.sos-reason, .sos-strong { font-size: 1.25rem; font-weight: 800; }
.sos-count { font-size: clamp(4rem, 30vw, 9rem); font-weight: 900; line-height: 1; margin: 0.5rem 0; font-variant-numeric: tabular-nums; }
.sos-count-text { font-size: 1.3rem; font-weight: 800; }
.sos-small { font-size: 1rem; margin: 0; }
.sos-honest { font-size: 1.05rem; border: 3px solid currentColor; border-radius: var(--radius); padding: 0.75rem; margin-top: 1.25rem; }
.sos a:not(.btn) { color: inherit; font-weight: 800; display: inline-block; min-height: var(--target); padding-block: 0.6rem; }
.sos .btn { border-width: 4px; }
.btn-sos-call { background: #ffffff; color: #000000; border-color: #ffffff; }
.btn-sos-sms { background: #000000; color: #ffffff; border-color: #ffffff; }
.btn-sos-secondary { width: 100%; background: transparent; color: inherit; border-color: currentColor; min-height: 56px; }
.sos :focus-visible { outline: 5px solid currentColor; outline-offset: 4px; box-shadow: 0 0 0 10px #000000; }
dialog.sos[data-state="countdown"] :focus-visible { box-shadow: 0 0 0 10px #ffffff; }
dialog.sos[data-state="sent"] .sos-icon { animation: pulse 1s ease-in-out infinite alternate; }
@keyframes pulse { from { transform: scale(1); } to { transform: scale(1.12); } }

/* ----- preferences ------------------------------------------------------------------------ */

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

@media (forced-colors: active) {
  .level-badge, .conn-dot, .sos-icon { border: 2px solid CanvasText; forced-color-adjust: none; }
  :focus-visible { outline: 4px solid Highlight; box-shadow: none; }
  dialog.sos { border: 6px solid CanvasText; }
}

[hidden] { display: none !important; }