/* 科目二 / 科目三 学车教程(/xueche/) */

.st-head { text-align: center; margin-bottom: 18px; }
.st-head h1 { font-size: 26px; margin-bottom: 6px; }
.st-sub { color: var(--text-sub); font-size: 14px; }

.st-tabs { display: inline-flex; gap: 6px; margin-top: 14px; background: var(--card);
  padding: 5px; border-radius: 999px; box-shadow: var(--shadow); }
.st-tab { padding: 7px 18px; border-radius: 999px; font-size: 14px; color: var(--text-sub);
  text-decoration: none; transition: background .15s, color .15s; }
.st-tab:hover { color: var(--blue); }
.st-tab.active { background: var(--blue); color: #fff; }

.st-note { background: #fffbeb; border: 1px solid #fde68a; color: #92400e;
  border-radius: 10px; padding: 12px 14px; font-size: 13.5px; margin-bottom: 22px; }

.st-sec { margin-bottom: 34px; }
.st-sec-head { margin-bottom: 16px; }
.st-sec-head h2 { font-size: 21px; display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.st-sec-sub { font-size: 13px; font-weight: 400; color: var(--text-sub); }
.st-sec-head p { color: var(--text-sub); font-size: 14px; margin-top: 5px; }

.st-item { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 20px 22px; margin-bottom: 16px; }
.st-item h3 { font-size: 18px; display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.st-no { flex: none; width: 26px; height: 26px; border-radius: 50%; background: var(--blue-light);
  color: var(--blue); font-size: 13px; font-weight: 700;
  display: inline-flex; align-items: center; justify-content: center; }

/* 视频在左、图文在右;窄屏改成上下 */
.st-body { display: flex; gap: 20px; align-items: flex-start; }
.st-media { flex: none; width: 340px; }
.st-text { flex: 1; min-width: 0; }

.st-video { width: 100%; aspect-ratio: 16 / 9; border-radius: 10px;
  background: #1a1d21; border: 1px solid var(--border); display: block; }
.st-vtitle { font-size: 12.5px; color: var(--text-sub); margin-top: 6px; text-align: center; }

/* 没配视频时的占位。不用灰底大方块 —— 那会让人以为页面坏了,
   写清楚"图文已完整"才不会白等。 */
.st-novideo { width: 100%; aspect-ratio: 16 / 9; border-radius: 10px;
  border: 1px dashed var(--border); background: var(--bg);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px;
  color: var(--text-sub); font-size: 14px; }
.st-novideo-ico { font-size: 26px; opacity: .5; }
.st-novideo em { font-size: 12px; font-style: normal; opacity: .75; }

.st-goal { background: var(--blue-light); border-radius: 8px; padding: 10px 12px;
  font-size: 14.5px; color: #1e40af; margin-bottom: 14px; }
.st-goal strong { display: block; font-size: 12.5px; opacity: .8; margin-bottom: 2px; }

.st-text h4 { font-size: 14px; margin: 14px 0 7px; color: var(--text-sub); }
.st-steps { margin-left: 20px; }
.st-steps li { font-size: 14.5px; margin-bottom: 5px; }

.st-deduct { list-style: none; }
.st-deduct li { font-size: 14.5px; margin-bottom: 6px; display: flex; gap: 9px; align-items: flex-start; }
/* 徽标固定宽度,让右侧说明文字对齐成一列,扫读时快得多 */
.st-badge { flex: none; min-width: 56px; text-align: center; font-size: 12px; font-weight: 600;
  padding: 2px 8px; border-radius: 5px; margin-top: 2px;
  background: #fef3c7; color: #92400e; }
.st-badge.st-fail { background: var(--red-light); color: var(--red); }

.st-tip { margin-top: 14px; padding: 11px 13px; border-left: 3px solid var(--green);
  background: var(--green-light); border-radius: 0 8px 8px 0; font-size: 14px; }
.st-tip strong { display: block; margin-bottom: 3px; color: #15803d; font-size: 13px; }

.st-foot { text-align: center; color: var(--text-sub); font-size: 14px; margin-top: 8px; }
.st-foot a { color: var(--blue); text-decoration: none; }
.st-foot a:hover { text-decoration: underline; }

@media (max-width: 760px) {
  .st-body { flex-direction: column; }
  .st-media { width: 100%; }
  .st-item { padding: 16px 14px; }
}