/* Login Page CSS — Dr. Chen's Biology Academy */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root { --green: #1a4731; --green-dark: #0f2d1a; --gold: #c9a84c; --gold-light: #e8c97a; --white: #fff; }
body {
  font-family: 'Inter', sans-serif; background: var(--green-dark);
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  background-image: linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 50px 50px;
}
.login-card { background: #0f2318; border: 1px solid rgba(45,122,82,0.3); border-radius: 16px; padding: 44px 40px; width: 100%; max-width: 400px; box-shadow: 0 24px 80px rgba(0,0,0,0.5); }
.lock-icon { text-align: center; font-size: 1.8rem; margin-bottom: 14px; }
.logo { font-family: 'Playfair Display', serif; font-size: 1.2rem; font-weight: 700; color: var(--gold); text-align: center; margin-bottom: 4px; line-height: 1.3; }
.logo span { color: rgba(255,255,255,0.4); display: block; }
.subtitle { text-align: center; font-size: 0.82rem; color: rgba(255,255,255,0.35); margin-bottom: 32px; }
.flash-msg { padding: 11px 15px; border-radius: 7px; margin-bottom: 18px; font-size: 0.87rem; font-weight: 500; }
.flash-msg.error { background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.3); color: #f87171; }
.form-group { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; }
label { font-size: 0.78rem; font-weight: 600; color: rgba(255,255,255,0.45); }
input { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); color: var(--white); border-radius: 7px; padding: 12px 14px; font-family: 'Inter', sans-serif; font-size: 0.91rem; transition: border-color 0.2s; width: 100%; }
input:focus { outline: none; border-color: rgba(45,122,82,0.8); }
button { width: 100%; background: var(--green); color: var(--white); border: none; cursor: pointer; padding: 13px; border-radius: 7px; font-weight: 700; font-size: 0.93rem; font-family: 'Inter', sans-serif; margin-top: 6px; transition: all 0.2s; }
button:hover { background: #1e5c3a; transform: translateY(-1px); }
.back-link { display: block; text-align: center; margin-top: 18px; font-size: 0.81rem; color: rgba(255,255,255,0.25); text-decoration: none; transition: color 0.2s; }
.back-link:hover { color: var(--gold); }