:root {
  color-scheme: light;
  --bg: #eef3f8;
  --panel: #ffffff;
  --text: #172033;
  --muted: #677287;
  --line: #d7deea;
  --track: #e7edf5;
  --track-active: #2f7de1;
  --track-success: #24a667;
  --track-fail: #d94a45;
  --shadow: 0 18px 50px rgba(25, 36, 58, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family:
    Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--text);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(255, 255, 255, 0)),
    var(--bg);
}

button {
  font: inherit;
}

.page-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.captcha-card {
  width: min(100%, 420px);
  padding: 24px;
  border: 1px solid rgba(129, 143, 164, 0.22);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.captcha-card h1 {
  margin: 0;
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.15;
  letter-spacing: 0;
}

.captcha-status {
  min-height: 22px;
  margin: 8px 0 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
}

.captcha-status.is-success {
  color: var(--track-success);
}

.captcha-status.is-fail {
  color: var(--track-fail);
}

.slider-handle:focus-visible {
  outline: 3px solid rgba(47, 125, 225, 0.26);
  outline-offset: 3px;
}

.slider {
  position: relative;
  height: 48px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--track);
  user-select: none;
  touch-action: none;
}

.slider-fill {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  background: rgba(47, 125, 225, 0.16);
}

.slider-label {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 0 64px;
  color: #6b7687;
  font-size: 14px;
  white-space: nowrap;
  pointer-events: none;
}

.slider-handle {
  position: absolute;
  inset: 4px auto 4px 4px;
  width: 40px;
  border: 0;
  border-radius: 8px;
  color: #ffffff;
  background: var(--track-active);
  box-shadow: 0 6px 14px rgba(47, 125, 225, 0.28);
  cursor: grab;
  will-change: transform;
}

.slider-handle:active {
  cursor: grabbing;
}

.captcha-card.is-resetting .slider-handle,
.captcha-card.is-resetting .slider-fill {
  transition:
    transform 260ms ease,
    width 260ms ease;
}

.captcha-card.is-success .slider-fill {
  background: rgba(36, 166, 103, 0.18);
}

.captcha-card.is-success .slider-handle {
  background: var(--track-success);
  box-shadow: 0 6px 14px rgba(36, 166, 103, 0.26);
}

.captcha-card.is-fail .slider-fill {
  background: rgba(217, 74, 69, 0.16);
}

.captcha-card.is-fail .slider-handle {
  background: var(--track-fail);
  box-shadow: 0 6px 14px rgba(217, 74, 69, 0.24);
}

@media (max-width: 440px) {
  .page-shell {
    padding: 14px;
  }

  .captcha-card {
    padding: 18px;
  }
}