:root {
  --sapp-bg: #eef3f6;
  --sapp-surface: #ffffff;
  --sapp-ink: #0f2a37;
  --sapp-muted: #5b6e7c;
  --sapp-line: #dbe5ec;
  --sapp-brand: #0f3b4f;
  --sapp-brand-2: #1f6390;
  --sapp-accent: #ffb947;
  --sapp-danger: #b91c1c;
  --sapp-topbar: 58px;
  --sapp-sidenav: 232px;
  --sapp-tabbar: 64px;
}

body.student-app {
  background: var(--sapp-bg);
  min-height: 100vh;
  min-height: 100dvh;
}

body.student-app-auth {
  background:
    linear-gradient(160deg, rgba(7, 24, 35, 0.72) 0%, rgba(15, 59, 79, 0.78) 55%, rgba(31, 99, 144, 0.7) 100%),
    #0f3b4f;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: max(16px, env(safe-area-inset-top)) 16px max(16px, env(safe-area-inset-bottom));
}

body.student-app-auth .login-shell,
body.student-app-auth main {
  width: 100%;
  max-width: 430px;
  margin: 0 auto;
  padding: 0;
}

.sapp-topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  min-height: var(--sapp-topbar);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: calc(8px + env(safe-area-inset-top)) 16px 8px;
  background: linear-gradient(95deg, var(--sapp-brand) 0%, var(--sapp-brand-2) 100%);
  color: #fff;
  box-shadow: 0 6px 18px rgba(15, 59, 79, 0.18);
}

.sapp-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.sapp-brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: #fff;
  color: var(--sapp-brand);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  flex-shrink: 0;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.18);
}

.sapp-brand-mark img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.sapp-brand-text {
  min-width: 0;
}

.sapp-brand-text strong {
  display: block;
  font-size: 0.95rem;
  line-height: 1.15;
}

.sapp-brand-text span {
  display: block;
  font-size: 0.72rem;
  opacity: 0.82;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 46vw;
}

.sapp-install-btn {
  border: 0;
  border-radius: 999px;
  background: var(--sapp-accent);
  color: #0f2a37;
  font-weight: 700;
  font-size: 0.78rem;
  padding: 0.42rem 0.85rem;
  display: none;
}

.sapp-install-btn.is-visible {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

body.sapp-installed .sapp-install-btn,
body.sapp-installed .sapp-install-banner {
  display: none !important;
}

.sapp-install-banner {
  display: none;
  margin: 0 0 1rem;
  border: 1px solid #dbe7df;
  background: #fff;
  border-radius: 14px;
  padding: 12px 14px;
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.04);
}

.sapp-install-banner.is-visible {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.sapp-install-banner p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--sapp-muted);
}

.sapp-install-banner strong {
  display: block;
  color: var(--sapp-ink);
  margin-bottom: 2px;
}

.sapp-layout {
  display: block;
}

.sapp-sidenav {
  display: none;
}

.sapp-main {
  padding-bottom: calc(var(--sapp-tabbar) + env(safe-area-inset-bottom) + 16px);
}

.sapp-tabbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 50;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  padding: 6px 10px calc(6px + env(safe-area-inset-bottom));
  background: rgba(255, 255, 255, 0.96);
  border-top: 1px solid var(--sapp-line);
  backdrop-filter: blur(10px);
}

.sapp-tab {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  min-height: 48px;
  text-decoration: none;
  color: #64748b;
  font-size: 0.68rem;
  font-weight: 600;
  border-radius: 12px;
  position: relative;
}

.sapp-tab i {
  font-size: 1.05rem;
}

.sapp-tab.is-active,
.sapp-tab:hover {
  color: var(--sapp-brand);
  background: #eef6fb;
}

.sapp-tab .sapp-badge {
  position: absolute;
  top: 4px;
  right: calc(50% - 18px);
  min-width: 16px;
  height: 16px;
  border-radius: 999px;
  background: #dc2626;
  color: #fff;
  font-size: 0.62rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 4px;
}

.sapp-login {
  background: #fff;
  border-radius: 1.6rem;
  padding: 1.4rem 1.25rem 1.2rem;
  box-shadow: 0 24px 50px rgba(0, 0, 0, 0.22);
}

.sapp-login .input-group {
  display: block;
  width: 100%;
}

.sapp-login .sapp-install-banner {
  margin-top: 1.15rem;
}

.sapp-login-hero {
  text-align: center;
  margin-bottom: 1.15rem;
}

.sapp-login-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 0.35rem;
}

.sapp-login-hero .sapp-brand-mark {
  width: 48px;
  height: 48px;
  margin: 0;
  border-radius: 50%;
}

.sapp-login-hero h1 {
  font-size: 1.45rem;
  font-weight: 800;
  color: #0a2b3e;
  margin: 0;
}

.sapp-login-hero p {
  margin: 0;
  color: #5a6e7c;
  font-size: 0.9rem;
}

.sapp-only-note {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #fff8eb;
  border: 1px solid #f3e0b8;
  color: #8a5a12;
  border-radius: 12px;
  padding: 0.7rem 0.8rem;
  font-size: 0.8rem;
  margin-bottom: 1rem;
}

.sapp-staff-link {
  display: block;
  text-align: center;
  margin-top: 1rem;
  font-size: 0.8rem;
  color: #1f6390;
  font-weight: 600;
  text-decoration: none;
}

.sapp-ios-help ol {
  margin: 0.4rem 0 0;
  padding-left: 1.1rem;
  font-size: 0.82rem;
  color: var(--sapp-muted);
}

@media (min-width: 992px) {
  body.student-app {
    overflow: hidden;
    height: 100vh;
  }

  .sapp-layout {
    display: flex;
    height: calc(100vh - var(--sapp-topbar) - env(safe-area-inset-top));
  }

  .sapp-sidenav {
    display: flex;
    flex-direction: column;
    width: var(--sapp-sidenav);
    flex-shrink: 0;
    background: #fff;
    border-right: 1px solid var(--sapp-line);
    padding: 18px 12px;
    gap: 6px;
    height: 100%;
  }

  .sapp-sidenav .sapp-tab {
    flex-direction: row;
    justify-content: flex-start;
    gap: 10px;
    padding: 10px 12px;
    font-size: 0.9rem;
    min-height: 44px;
  }

  .sapp-sidenav .sapp-tab .sapp-badge {
    position: static;
    margin-left: auto;
  }

  .sapp-tabbar {
    display: none;
  }

  .sapp-main {
    flex: 1;
    min-width: 0;
    height: 100%;
    overflow-y: auto;
    padding: 24px 28px 40px;
  }

  body.student-app .page-wrap {
    max-width: 1080px;
    padding-top: 0 !important;
  }
}

@media (display-mode: standalone), (display-mode: minimal-ui) {
  body.student-app .sapp-install-banner,
  body.student-app-auth .sapp-install-banner {
    display: none !important;
  }
}