/* 首次启动引导：认识一下 → 测词汇量 */
.ob {
  position: fixed;
  inset: 0;
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background:
    radial-gradient(1100px 620px at 18% -10%, rgba(28, 107, 85, 0.16), transparent 60%),
    radial-gradient(900px 560px at 96% 12%, rgba(122, 156, 214, 0.14), transparent 58%),
    var(--bg, #f6f5f1);
  opacity: 0;
  transition: opacity 0.34s var(--ease-out, ease);
}
.ob[hidden] { display: none; }
.ob.is-open { opacity: 1; }

.ob-card {
  position: relative;
  width: min(560px, 100%);
  padding: 34px 34px 28px;
  border-radius: 26px;
  background: color-mix(in srgb, var(--surface, #fff) 92%, transparent);
  border: 1px solid color-mix(in srgb, var(--line, #e9e6de) 88%, transparent);
  box-shadow: 0 34px 80px -32px rgba(20, 40, 34, 0.42), 0 2px 0 rgba(255, 255, 255, 0.5) inset;
  backdrop-filter: blur(18px) saturate(1.2);
  transform: translateY(22px) scale(0.978);
  transition: transform 0.44s cubic-bezier(0.16, 1, 0.3, 1);
}
.ob.is-open .ob-card { transform: none; }

.ob-badge {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 15px;
  background: linear-gradient(160deg, color-mix(in srgb, var(--accent, #1c6b55) 20%, transparent), color-mix(in srgb, var(--accent, #1c6b55) 8%, transparent));
  color: var(--accent-deep, #14503f);
  margin-bottom: 16px;
}
.ob-badge svg { width: 24px; height: 24px; }

.ob-h { margin: 0 0 6px; font-size: 23px; letter-spacing: -0.01em; }
.ob-p { margin: 0 0 18px; font-size: 13.5px; line-height: 1.75; color: var(--muted, #74777e); }

.ob-field { margin-bottom: 14px; }
.ob-lab { display: block; font-size: 11.5px; letter-spacing: 0.08em; color: var(--faint, #9a9da4); margin-bottom: 7px; }
.ob-input {
  width: 100%;
  height: 48px;
  padding: 0 15px;
  border-radius: 13px;
  border: 1px solid var(--line, #e9e6de);
  background: var(--surface, #fff);
  color: var(--ink, #191b1f);
  font: 15px/1.4 inherit;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}
.ob-input:focus {
  outline: none;
  border-color: color-mix(in srgb, var(--accent, #1c6b55) 55%, transparent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent, #1c6b55) 12%, transparent);
}

.ob-grades { display: grid; grid-template-columns: repeat(6, 1fr); gap: 7px; }
.ob-grade {
  height: 40px;
  border-radius: 11px;
  border: 1px solid var(--line, #e9e6de);
  background: var(--surface, #fff);
  color: var(--ink-2, #3a3e45);
  font: 13px/1 inherit;
  cursor: pointer;
  transition: transform 0.14s ease, border-color 0.16s ease, background 0.16s ease;
}
.ob-grade:hover { transform: translateY(-1px); border-color: color-mix(in srgb, var(--accent, #1c6b55) 34%, transparent); }
.ob-grade.is-on {
  border-color: var(--accent, #1c6b55);
  background: color-mix(in srgb, var(--accent, #1c6b55) 12%, transparent);
  color: var(--accent-deep, #14503f);
  font-weight: 650;
}

.ob-hint {
  margin: 16px 0 0;
  padding: 12px 14px;
  border-radius: 13px;
  background: color-mix(in srgb, var(--accent, #1c6b55) 7%, transparent);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--accent-deep, #14503f);
}
.ob-hint b { font-variant-numeric: tabular-nums; }

.ob-foot { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 22px; }
.ob-step { font-size: 11.5px; letter-spacing: 0.1em; color: var(--faint, #9a9da4); }
.ob-btn {
  height: 44px;
  padding: 0 22px;
  border-radius: 13px;
  border: 1px solid transparent;
  background: var(--accent, #1c6b55);
  color: #fff;
  font: 14px/1 inherit;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.14s ease, filter 0.16s ease;
}
.ob-btn:hover { filter: brightness(1.06); }
.ob-btn:active { transform: translateY(1px) scale(0.99); }
.ob-btn[disabled] { opacity: 0.45; cursor: not-allowed; }

.ob-list { margin: 0 0 4px; padding: 0; list-style: none; }
.ob-list li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-2, #3a3e45);
  padding: 6px 0;
}
.ob-list i {
  flex: 0 0 20px;
  height: 20px;
  border-radius: 7px;
  display: grid;
  place-items: center;
  font-style: normal;
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-deep, #14503f);
  background: color-mix(in srgb, var(--accent, #1c6b55) 13%, transparent);
}

[data-theme='dark'] .ob { background: radial-gradient(1100px 620px at 18% -10%, rgba(46, 139, 111, 0.2), transparent 60%), #0b0d0e; }
[data-theme='dark'] .ob-card { background: rgba(24, 27, 29, 0.92); border-color: rgba(255, 255, 255, 0.08); box-shadow: 0 34px 80px -30px rgba(0, 0, 0, 0.7); }
[data-theme='dark'] .ob-input,
[data-theme='dark'] .ob-grade { background: rgba(255, 255, 255, 0.04); border-color: rgba(255, 255, 255, 0.12); color: #eceef1; }
[data-theme='dark'] .ob-hint { background: rgba(46, 139, 111, 0.16); color: #bfe6d5; }

@media (max-width: 560px) {
  .ob-card { padding: 26px 22px 22px; border-radius: 22px; }
  .ob-grades { grid-template-columns: repeat(4, 1fr); }
}
@media (prefers-reduced-motion: reduce) {
  .ob, .ob-card { transition: none; }
}

/* ---------- 引导第二步：强制摸底 ---------- */
.ob-quiz { max-width: 620px; }
.ob-qtop { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.ob-qcount { font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; }
.ob-bar { height: 5px; border-radius: 99px; background: color-mix(in srgb, var(--ink) 10%, transparent); overflow: hidden; }
.ob-bar > i { display: block; height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.32s var(--ease-out, ease); }
.ob-qp { margin: 18px 0 4px; font-size: 12.5px; color: var(--muted); }
.ob-qword {
  font-family: var(--font-serif); font-size: clamp(30px, 4vw, 40px); letter-spacing: -0.01em;
  color: var(--ink); text-align: center; padding: 22px 0 26px; word-break: break-word;
}
.ob-opts { display: flex; flex-direction: column; gap: 9px; }
.ob-opt {
  display: flex; align-items: center; gap: 12px; width: 100%; text-align: left;
  padding: 13px 16px; border-radius: 14px; cursor: pointer;
  border: 1px solid color-mix(in srgb, var(--line) 92%, transparent);
  background: color-mix(in srgb, var(--surface) 86%, transparent);
  color: var(--ink); font-size: 14.5px;
  transition: transform 0.14s var(--ease, ease), border-color 0.14s, background 0.14s;
}
.ob-opt:hover { transform: translateY(-1px); border-color: color-mix(in srgb, var(--accent) 42%, var(--line)); }
.ob-opt > i {
  flex: 0 0 24px; height: 24px; border-radius: 8px; display: grid; place-items: center;
  font-style: normal; font-size: 12px; font-weight: 700;
  background: color-mix(in srgb, var(--ink) 7%, transparent); color: var(--muted);
}
.ob-opt.is-right { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 14%, var(--surface)); }
.ob-opt.is-right > i { background: var(--accent); color: #fff; }
.ob-opt.is-wrong { border-color: #c0504d; background: color-mix(in srgb, #c0504d 12%, var(--surface)); }
.ob-opt.is-wrong > i { background: #c0504d; color: #fff; }
.ob-opt.is-dim { opacity: 0.5; }
.ob-opt:disabled { cursor: default; }
.ob-ghost { background: transparent !important; border: 1px solid var(--line) !important; color: var(--muted) !important; }
.ob-kbd { font-size: 11.5px; color: var(--faint); }
.ob-note { font-size: 11.5px; line-height: 1.7; color: var(--faint); margin: 14px 0 0; }
.ob-lock { border-top: 1px dashed color-mix(in srgb, var(--ink) 10%, transparent); padding-top: 10px; }
.ob.is-locked .ob-card { border-color: color-mix(in srgb, var(--accent) 26%, var(--line)); }

/* ---------- 引导第三步：计划 ---------- */
.ob-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.ob-chip {
  padding: 9px 15px; border-radius: 99px; cursor: pointer; font-size: 13px;
  border: 1px solid color-mix(in srgb, var(--line) 92%, transparent);
  background: color-mix(in srgb, var(--surface) 86%, transparent); color: var(--muted);
  transition: all 0.14s var(--ease, ease);
}
.ob-chip:hover { color: var(--ink); }
.ob-chip.is-on { border-color: var(--accent); color: var(--accent-ink); background: var(--accent-soft); font-weight: 600; }
.ob-task {
  margin: 20px 0 4px; padding: 16px 18px; border-radius: 16px;
  background: color-mix(in srgb, var(--accent) 7%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--accent) 20%, transparent);
}
.ob-task-h { font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent-ink); font-weight: 700; margin-bottom: 10px; }
.ob-task-l { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.ob-task-l li { display: flex; flex-direction: column; gap: 2px; font-size: 13px; color: var(--ink); }
.ob-task-l li span { font-size: 11.5px; color: var(--muted); }
:root[data-theme='dark'] .ob-task { background: color-mix(in srgb, var(--accent) 14%, #14181a); }
/* 空值校验：错误文案 + 输入框描红 + 轻微抖动 */
.ob-err {
  margin: 8px 0 8px;
  font-size: 12px;
  color: #b4453c;
  line-height: 1.6;
}
.ob-err[hidden] { display: none; }
.ob-input.is-bad { border-color: #d4918c; box-shadow: 0 0 0 3px rgba(180, 69, 60, 0.08); }
.ob-field--name.is-shake { animation: obShake 0.34s cubic-bezier(0.36, 0.07, 0.19, 0.97); }
@keyframes obShake {
  0%, 100% { transform: translateX(0); }
  22% { transform: translateX(-5px); }
  46% { transform: translateX(4px); }
  70% { transform: translateX(-2px); }
}
@media (prefers-reduced-motion: reduce) {
  .ob-field--name.is-shake { animation: none; }
}