/* 学生端样式 */
.login-card .student-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin: 14px 0; }
.student-btn {
  background: #eef5fd; border: 2px solid #d4e4f7; border-radius: 12px; padding: 14px 6px;
  font-size: 16px; color: var(--ink); transition: all .15s;
}
.student-btn:hover { border-color: var(--blue); background: #e2eefb; transform: translateY(-2px); }
.demo-note { color: var(--muted); font-size: 13px; }

.steps-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-bottom: 18px; }
.step-card {
  background: #fff; border-radius: 14px; padding: 18px 10px; text-align: center; cursor: pointer;
  box-shadow: 0 4px 14px rgba(31,78,121,.08); transition: transform .15s; border-bottom: 4px solid var(--blue);
}
.step-card:hover { transform: translateY(-4px); }
.step-card .icon { font-size: 32px; }
.step-card .name { font-weight: 700; margin: 6px 0 4px; }
.step-card .status { font-size: 13px; color: var(--muted); }
.step-card .status.done { color: var(--green); font-weight: 700; }

.tip-card { text-align: center; }
.tip-card p { margin: 6px 0; color: var(--muted); }
.big-formula { font-size: 30px !important; color: var(--blue-deep) !important; font-weight: 800; letter-spacing: 3px; margin: 10px 0 !important; }

.situation-box { background: #fff8e8; border: 2px dashed #f2d9a0; border-radius: 12px; padding: 14px 18px; font-size: 17px; line-height: 1.8; margin-bottom: 14px; }
.concept-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.concept { background: #f0f7ff; border-radius: 12px; padding: 14px; text-align: center; font-size: 14px; line-height: 1.7; color: var(--muted); }
.concept .c-title { font-size: 17px; font-weight: 800; color: var(--blue-deep); margin-bottom: 4px; }
.key-line { margin-top: 14px; font-size: 17px; text-align: center; background: #e8f8f0; border-radius: 10px; padding: 10px; }

.q-item { margin: 16px 0; padding: 12px; background: #f8fbfe; border-radius: 10px; }
.q-item .q-text { font-weight: 600; margin-bottom: 8px; }
.q-item label { display: inline-flex; align-items: center; gap: 6px; margin-right: 18px; cursor: pointer; padding: 4px 10px; border-radius: 8px; }
.q-item label:hover { background: #e8f1fd; }
.fill-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.fill-row input { width: 72px; padding: 8px; border: 2px solid #d4e4f7; border-radius: 8px; font-size: 16px; text-align: center; }
.fill-row input:focus { border-color: var(--blue); outline: none; }
textarea.say { width: 100%; min-height: 84px; padding: 10px; border: 2px solid #d4e4f7; border-radius: 10px; font-size: 15px; resize: vertical; }
textarea.say:focus { border-color: var(--blue); outline: none; }
.q-result { margin-top: 10px; font-size: 14px; }

/* 聊天区 */
.chat-card { padding: 18px; }
.chat-head { display: flex; justify-content: space-between; align-items: center; }
.stage-bar { display: flex; gap: 4px; margin: 12px 0; flex-wrap: wrap; }
.stage-chip { font-size: 12px; padding: 4px 10px; border-radius: 999px; background: #eef2f7; color: var(--muted); }
.stage-chip.active { background: var(--blue); color: #fff; font-weight: 700; }
.stage-chip.passed { background: #d9f2e6; color: #1d7a53; }
.chat-box {
  height: 380px; overflow-y: auto; background: #f6f9fc; border-radius: 12px; padding: 14px;
  display: flex; flex-direction: column; gap: 10px; border: 1px solid var(--line);
}
.bubble { max-width: 78%; padding: 10px 14px; border-radius: 14px; line-height: 1.7; font-size: 15px; white-space: pre-wrap; word-break: break-word; }
.bubble.ai { background: #fff; border: 1px solid var(--line); border-top-left-radius: 4px; align-self: flex-start; }
.bubble.student { background: var(--blue); color: #fff; border-top-right-radius: 4px; align-self: flex-end; }
.bubble .b-name { font-size: 12px; opacity: .75; display: block; margin-bottom: 2px; }
.chat-input-row { display: flex; gap: 10px; margin-top: 12px; }
.chat-input-row input {
  flex: 1; padding: 12px 14px; border: 2px solid #d4e4f7; border-radius: 10px; font-size: 15px;
}
.chat-input-row input:focus { border-color: var(--blue); outline: none; }
.chat-finished-tip { text-align: center; color: var(--green); font-weight: 700; margin-top: 10px; }
.fallback-note {
  align-self: center; font-size: 12px; color: #9a6b00; background: #fff6dc;
  border: 1px dashed #e8cf90; border-radius: 999px; padding: 3px 12px; margin-top: 2px;
}

/* 成绩面板 */
.score-panel { margin-top: 14px; background: #f0f9ff; border: 2px solid #bfe3ff; border-radius: 14px; padding: 18px; }
.score-panel h4 { font-size: 18px; color: var(--blue-deep); margin-bottom: 10px; }
.dim-row { display: flex; align-items: center; gap: 10px; margin: 8px 0; font-size: 14px; }
.dim-row .d-name { width: 80px; text-align: right; }
.dim-bar { flex: 1; height: 14px; background: #e2edf7; border-radius: 999px; overflow: hidden; }
.dim-bar > div { height: 100%; background: linear-gradient(90deg, var(--blue), var(--green)); border-radius: 999px; }
.dim-row .d-score { width: 64px; font-weight: 700; }
.total-line { font-size: 22px; font-weight: 800; color: var(--orange); margin: 10px 0; }
.fb-text { background: #fff; border-radius: 10px; padding: 12px; line-height: 1.8; font-size: 15px; }

/* 成绩页 */
.score-block { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 14px 0; }
.score-tile { background: #f8fbfe; border-radius: 12px; padding: 16px; text-align: center; }
.score-tile .s-num { font-size: 34px; font-weight: 800; color: var(--blue-deep); }
.score-tile .s-name { color: var(--muted); font-size: 14px; margin-top: 4px; }