:root {
      --green-dark: #063d35;
      --gold: #f4ce58;
      --gold-light: #fff0ad;
      --white: #fff;
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    html { min-height: 100%; background: var(--green-dark); }

    body {
      position: relative;
      min-height: 100vh;
      min-height: 100svh;
      min-height: 100dvh;
      padding: max(20px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) max(20px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      color: var(--white);
      background: var(--green-dark);
      display: grid;
      place-items: center;
      overflow-x: hidden;
    }

    body::before {
      content: "";
      position: fixed;
      inset: 0;
      z-index: 0;
      background: url("/bg_index.JPG") center / cover no-repeat;
      transform: scale(1.01);
      animation: backgroundZoom 22s ease-in-out infinite alternate;
    }

    body::after {
      content: "";
      position: fixed;
      inset: 0;
      z-index: 0;
      pointer-events: none;
      background:
        linear-gradient(135deg, rgba(2, 27, 24, .38), rgba(5, 73, 59, .18)),
        radial-gradient(circle at 50% 40%, transparent 18%, rgba(0, 18, 16, .15) 100%);
    }

    @keyframes backgroundZoom {
      from { transform: scale(1.01); }
      to { transform: scale(1.055); }
    }

    .admin-lock {
      position: fixed;
      top: max(14px, env(safe-area-inset-top));
      left: max(14px, env(safe-area-inset-left));
      z-index: 20;
      width: 34px;
      height: 34px;
      border: 1px solid rgba(255, 255, 255, .28);
      border-radius: 10px;
      color: rgba(255, 255, 255, .74);
      background: rgba(4, 35, 31, .18);
      -webkit-backdrop-filter: blur(5px);
      backdrop-filter: blur(5px);
      display: grid;
      place-items: center;
      text-decoration: none;
      box-shadow: 0 5px 18px rgba(0, 0, 0, .13);
      transition: 180ms ease;
    }

    .admin-lock:hover,
    .admin-lock:focus-visible {
      color: var(--gold);
      background: rgba(4, 35, 31, .42);
      border-color: rgba(244, 206, 88, .7);
      transform: translateY(-2px);
      outline: none;
    }

    .admin-lock svg { width: 15px; height: 15px; }

    .page-shell {
      position: relative;
      z-index: 2;
      width: min(100%, 420px);
      margin: auto;
    }

    .login-card {
      width: 100%;
      padding: clamp(24px, 4vw, 32px);
      text-align: center;
      border: 1px solid rgba(255, 255, 255, .28);
      border-radius: 25px;
      background: linear-gradient(145deg, rgba(4, 57, 48, .25), rgba(4, 42, 37, .13));
      -webkit-backdrop-filter: blur(7px) saturate(115%);
      backdrop-filter: blur(7px) saturate(115%);
      box-shadow: 0 20px 55px rgba(0, 18, 16, .23), inset 0 1px 0 rgba(255, 255, 255, .16);
      animation: cardEntrance 650ms cubic-bezier(.16, 1, .3, 1) both;
    }

    @keyframes cardEntrance {
      from { opacity: 0; transform: translateY(28px) scale(.98); }
      to { opacity: 1; transform: translateY(0) scale(1); }
    }

    .brand-mark {
      width: 104px;
      height: 104px;
      margin: 0 auto 18px;
      border: 0;
      border-radius: 22px;
      overflow: visible;
      background: transparent;
      box-shadow: 0 9px 25px rgba(0, 24, 20, .16);
      display: grid;
      place-items: center;
    }

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

    .eyebrow {
      margin-bottom: 8px;
      color: rgba(222, 255, 244, .9);
      font-size: clamp(.59rem, 1.5vw, .68rem);
      line-height: 1.45;
      font-weight: 800;
      letter-spacing: .14em;
      text-transform: uppercase;
    }

    h1 {
      max-width: 340px;
      margin-inline: auto;
      font-family: Georgia, "Times New Roman", serif;
      font-size: clamp(1.48rem, 4.2vw, 1.9rem);
      line-height: 1.18;
      letter-spacing: -.02em;
      text-wrap: balance;
      text-shadow: 0 3px 14px rgba(0, 20, 17, .2);
    }

    .subtitle {
      max-width: 325px;
      margin: 13px auto 22px;
      color: rgba(255, 255, 255, .86);
      font-size: clamp(.78rem, 2vw, .88rem);
      line-height: 1.55;
    }

    .teacher-login {
      position: relative;
      overflow: hidden;
      width: 100%;
      min-height: 50px;
      padding: 13px 20px;
      border: 0;
      border-radius: 14px;
      color: #05372f;
      background: linear-gradient(135deg, var(--gold-light), var(--gold));
      box-shadow: 0 10px 24px rgba(73, 54, 0, .2);
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 9px;
      font-size: .92rem;
      font-weight: 800;
      text-decoration: none;
      transition: transform 180ms ease, box-shadow 180ms ease, filter 180ms ease;
    }

    .teacher-login::after {
      content: "";
      position: absolute;
      top: 0;
      left: -110%;
      width: 68%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(255, 255, 255, .55), transparent);
      transform: skewX(-20deg);
      transition: left 520ms ease;
    }

    .teacher-login:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(73, 54, 0, .28); filter: brightness(1.03); }
    .teacher-login:hover::after { left: 135%; }
    .teacher-login:focus-visible { outline: 3px solid var(--white); outline-offset: 3px; }
    .teacher-login svg { width: 18px; height: 18px; flex: 0 0 auto; }

    .helper {
      max-width: 320px;
      margin: 15px auto 0;
      color: rgba(237, 255, 249, .74);
      font-size: clamp(.68rem, 1.8vw, .76rem);
      line-height: 1.5;
    }

    .footer {
      margin-top: 12px;
      color: rgba(255, 255, 255, .72);
      text-align: center;
      font-size: .66rem;
      letter-spacing: .06em;
      text-shadow: 0 2px 8px rgba(0, 0, 0, .35);
    }

    @media (max-width: 520px) {
      .page-shell { width: min(100%, 370px); }
      .login-card { padding: 23px 20px; border-radius: 22px; -webkit-backdrop-filter: blur(6px) saturate(110%); backdrop-filter: blur(6px) saturate(110%); }
      .brand-mark { width: 92px; height: 92px; margin-bottom: 15px; border-radius: 19px; }
      .subtitle { margin-bottom: 19px; }
      .admin-lock { width: 32px; height: 32px; border-radius: 9px; }
    }

    @media (max-height: 610px), (orientation: landscape) and (max-height: 520px) {
      body { overflow-y: auto; place-items: start center; }
      .page-shell { margin-block: auto; }
      .login-card { padding: 18px 22px; }
      .brand-mark { width: 76px; height: 76px; margin-bottom: 10px; border-radius: 16px; }
      .eyebrow { margin-bottom: 5px; font-size: .56rem; }
      h1 { font-size: 1.35rem; }
      .subtitle { margin: 8px auto 13px; font-size: .74rem; }
      .teacher-login { min-height: 44px; padding: 10px 18px; }
      .helper { margin-top: 10px; }
      .footer { margin-top: 7px; }
    }

    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after {
        scroll-behavior: auto !important;
        transition-duration: .01ms !important;
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
      }
    }