:root {
  color-scheme: light;
  --paper: #f4f7f8;
  --card: #ffffff;
  --ink: #172c3c;
  --muted: #506473;
  --green: #096b59;
  --green-dark: #075444;
  --mint: #e7f4ee;
  --line: #dce6e9;
  --focus: #b26b00;
  --shadow-soft: 0 8px 28px #172c3c08;
}

body.plainai-page {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.75 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
}

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

.plainai-page :is(a, button, input, select, textarea, summary):focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 5px;
}

.plainai-shell {
  width: min(1160px, calc(100% - 64px));
  margin-inline: auto;
}

.plainai-page > .plainai-shell:first-child {
  width: 100%;
  border-bottom: 1px solid var(--line);
}

.plainai-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1160px, calc(100% - 64px));
  margin-inline: auto;
  padding: 24px 0;
  border: 0;
  background: transparent;
  box-shadow: none;
  color: var(--ink);
}

.plainai-brand {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  gap: 10px;
  color: var(--green);
  font-size: 30px;
  line-height: 1.2;
  font-weight: 750;
  letter-spacing: -.9px;
  text-decoration: none;
}

.plainai-brand img {
  width: 64px;
  height: 40px;
  object-fit: contain;
}

.plainai-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 28px;
}

.plainai-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.plainai-nav a:hover,
.plainai-nav a[aria-current="page"] {
  color: var(--green);
}

.plainai-nav .nav-start {
  padding: 8px 16px;
  color: var(--green);
  background: var(--mint);
  border-radius: 8px;
  font-weight: 650;
}

.plainai-page .admin-nav {
  display: none;
}

.plainai-page > :is(header:not(.plainai-header), .header) {
  width: min(1160px, calc(100% - 64px));
  margin: 42px auto 22px;
  padding: 0 0 24px;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  box-shadow: none;
  color: var(--ink);
  text-align: left;
}

.plainai-page > :is(header:not(.plainai-header), .header) h1 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: clamp(32px, 3.6vw, 44px);
  font-weight: 750;
  line-height: 1.28;
  letter-spacing: -.045em;
  text-shadow: none;
}

.plainai-page > :is(header:not(.plainai-header), .header) p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
  opacity: 1;
  text-shadow: none;
}

.plainai-page > :is(header:not(.plainai-header), .header) a {
  color: var(--green) !important;
}

.plainai-page :is(.card, .panel, .voice-card, .color-card, .usage-section, .customize-section) {
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: none;
}

.plainai-page :is(.card, .panel, .voice-card, .color-card):hover {
  transform: none;
  box-shadow: var(--shadow-soft);
}

.plainai-page :is(button, .btn, .button, .play-button, .go-agent-btn, .copy-btn, .apply-btn, .reset-btn) {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--card);
  color: var(--ink);
  box-shadow: none;
  text-transform: none;
  letter-spacing: 0;
}

.plainai-page :is(button:hover, .btn:hover, .button:hover, .play-button:hover, .go-agent-btn:hover, .copy-btn:hover, .apply-btn:hover, .reset-btn:hover) {
  background: var(--mint);
  color: var(--green);
  transform: none;
  box-shadow: none;
}

.plainai-page :is(.btn-primary, .btn-success, .button.primary, .play-button, .go-agent-btn, button.primary) {
  border-color: var(--green);
  background: var(--green);
  color: #fff;
}

.plainai-page :is(.btn-primary:hover, .btn-success:hover, .button.primary:hover, .play-button:hover, .go-agent-btn:hover, button.primary:hover) {
  border-color: var(--green-dark);
  background: var(--green-dark);
  color: #fff;
}

.plainai-page :is(input, select, textarea) {
  border: 1px solid #c7d5d8;
  border-radius: 10px;
  background: var(--card);
  color: var(--ink);
}

.plainai-page :is(input, select, textarea):focus {
  border-color: var(--green);
  box-shadow: none;
  outline: 3px solid color-mix(in srgb, var(--focus) 28%, transparent);
}

@media (max-width: 760px) {
  .plainai-shell {
    width: calc(100% - 40px);
  }

  .plainai-page > .plainai-shell:first-child {
    width: 100%;
  }

  .plainai-header {
    width: calc(100% - 40px);
    flex-wrap: wrap;
    gap: 18px;
    padding: 20px 0 14px;
  }

  .plainai-page > :is(header:not(.plainai-header), .header) {
    width: calc(100% - 40px);
    margin-top: 32px;
    padding-bottom: 20px;
  }

  .plainai-brand {
    font-size: 28px;
  }

  .plainai-nav {
    width: 100%;
    justify-content: space-between;
    gap: 4px 12px;
  }

  .plainai-nav a {
    font-size: 12px;
  }
}