/* ============================================================
   化学课程招生网站 - 全局样式
   移动优先，桌面端自动扩展布局
   ============================================================ */

:root {
  --color-primary: #0F5C97;
  --color-primary-dark: #0B4570;
  --color-accent: #2FA84F;
  --color-bg: #F5F7F9;
  --color-card: #FFFFFF;
  --color-text: #1B2430;
  --color-text-muted: #667085;
  --color-border: #E3E8EE;
  --color-danger: #D64545;
  --radius: 14px;
  --shadow: 0 2px 10px rgba(16, 24, 40, 0.06);
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px 16px 48px;
}

/* ------------------ 顶部导航 ------------------ */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--color-primary);
  color: #fff;
  padding: 14px 16px;
  padding-top: calc(14px + env(safe-area-inset-top));
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.topbar .brand {
  font-size: 17px;
  font-weight: 700;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
}

.topbar .brand-logo {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: #fff;
  padding: 2px;
  display: block;
  flex-shrink: 0;
}

.topbar .nav-actions {
  display: flex;
  gap: 12px;
  align-items: center;
}

.topbar a, .topbar button.link {
  color: rgba(255, 255, 255, 0.92);
  font-size: 14px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px 4px;
}

/* ------------------ 卡片 ------------------ */
.card {
  background: var(--color-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 16px;
  border: 1px solid var(--color-border);
}

.card h2 {
  margin-top: 0;
  font-size: 18px;
}

.hero {
  text-align: center;
  padding: 32px 16px 8px;
}

.hero h1 {
  font-size: 24px;
  margin-bottom: 8px;
  color: var(--color-primary-dark);
}

.hero p {
  color: var(--color-text-muted);
  font-size: 15px;
  max-width: 480px;
  margin: 0 auto;
}

/* ------------------ 表单 ------------------ */
.form-group {
  margin-bottom: 14px;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="tel"],
textarea,
select {
  width: 100%;
  padding: 12px 14px;
  font-size: 15px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: #fff;
  color: var(--color-text);
  font-family: inherit;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(15, 92, 151, 0.12);
}

textarea {
  resize: vertical;
  min-height: 80px;
}

/* ------------------ 按钮 ------------------ */
.btn {
  display: inline-block;
  width: 100%;
  padding: 13px 18px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  text-align: center;
  transition: opacity 0.15s ease;
}

.btn:active {
  opacity: 0.8;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-secondary {
  background: #fff;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}

.btn-danger {
  background: #fff;
  color: var(--color-danger);
  border: 1px solid var(--color-danger);
}

.btn-sm {
  width: auto;
  padding: 8px 14px;
  font-size: 13px;
}

/* ------------------ 时间段选择卡片 ------------------ */
.slot-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px;
  border: 1.5px solid var(--color-border);
  border-radius: 10px;
  margin-bottom: 10px;
  cursor: pointer;
}

.slot-option input {
  width: auto;
}

.slot-option.selected {
  border-color: var(--color-primary);
  background: rgba(15, 92, 151, 0.05);
}

.slot-option .slot-label {
  font-weight: 600;
  font-size: 15px;
}

.slot-option .slot-meta {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* ------------------ 状态标签 ------------------ */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}

.badge-pending { background: #FFF4E5; color: #B26A00; }
.badge-confirmed { background: #E6F7EC; color: #1D8A3F; }
.badge-cancelled { background: #FBEAEA; color: var(--color-danger); }

/* ------------------ 通知列表 ------------------ */
.notice-item {
  border-bottom: 1px solid var(--color-border);
  padding: 14px 0;
}

.notice-item:last-child {
  border-bottom: none;
}

.notice-title {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 4px;
}

.notice-date {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

/* ------------------ 消息提示 ------------------ */
.msg {
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 14px;
  margin-bottom: 14px;
}

.msg-error {
  background: #FBEAEA;
  color: var(--color-danger);
}

.msg-success {
  background: #E6F7EC;
  color: #1D8A3F;
}

/* ------------------ 管理后台表格 ------------------ */
.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

th, td {
  text-align: left;
  padding: 10px 8px;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

th {
  color: var(--color-text-muted);
  font-size: 12px;
  text-transform: uppercase;
}

/* ------------------ Tabs (登录/注册 切换) ------------------ */
.tabs {
  display: flex;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 18px;
}

.tab {
  flex: 1;
  text-align: center;
  padding: 10px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.hidden {
  display: none !important;
}

/* ------------------ 桌面端加宽 ------------------ */
@media (min-width: 900px) {
  :root {
    --max-width: 860px;
  }
  .hero h1 {
    font-size: 30px;
  }
  .grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }
}

.footer-note {
  text-align: center;
  color: var(--color-text-muted);
  font-size: 12px;
  margin-top: 24px;
}

/* ------------------ 语言切换 ------------------ */
.lang-switch {
  display: flex;
  gap: 2px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  padding: 2px;
}

.lang-btn {
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.75);
  font-size: 12px;
  font-weight: 600;
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
}

.lang-btn.active {
  background: rgba(255, 255, 255, 0.95);
  color: var(--color-primary);
}

/* ------------------ 表单分节标题 ------------------ */
.form-section-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin: 22px 0 10px;
  padding-top: 14px;
  border-top: 1px solid var(--color-border);
}

.form-section-title:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

/* ------------------ 提示横幅 ------------------ */
.banner {
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 13px;
  margin-bottom: 16px;
}

.banner-info {
  background: #E9F2FA;
  color: var(--color-primary-dark);
}

.banner-warning {
  background: #FFF4E5;
  color: #B26A00;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.banner-warning .btn {
  width: auto;
}

/* ------------------ 同意书正文 ------------------ */
.consent-disclaimer {
  background: #FBEAEA;
  color: var(--color-danger);
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 13px;
  margin-bottom: 18px;
}

.consent-section {
  margin-bottom: 16px;
}

.consent-section h3 {
  font-size: 14px;
  margin-bottom: 4px;
  color: var(--color-primary-dark);
}

.consent-section p {
  font-size: 14px;
  color: var(--color-text);
  margin: 0;
}

.checkbox-row {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin: 16px 0;
}

.checkbox-row input {
  width: auto;
  margin-top: 3px;
}

.checkbox-row label {
  font-size: 14px;
  font-weight: 400;
  color: var(--color-text);
  margin: 0;
}