/* =========================
   RESET + BASE (Mobile First)
========================= */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Vazirmatn, Tahoma, sans-serif;
  background: radial-gradient(circle at top, #081b33, #050d1a);
  color: #e8f6ff;
  direction: rtl;
}

/* =========================
   FORM CONTAINER
========================= */
#signup {
  padding: 20px 16px 40px;
}

form {
  background: linear-gradient(
    180deg,
    rgba(0,229,255,0.08),
    rgba(5,13,26,0.95)
  );
  border-radius: 18px;
  padding: 22px 18px 30px;
  border: 1px solid rgba(0,229,255,0.25);
  box-shadow:
    0 0 25px rgba(0,229,255,0.15),
    inset 0 0 20px rgba(245,197,66,0.05);
}

/* =========================
   HEADINGS
========================= */
h3 {
  margin: 28px 0 14px;
  font-size: 1.05rem;
  color: #f5c542;
  border-right: 4px solid #00e5ff;
  padding-right: 10px;
  letter-spacing: 0.3px;
}

/* =========================
   INPUTS
========================= */
input,
select,
textarea {
  width: 100%;
  background: rgba(5,13,26,0.9);
  color: #ffffff;
  border: 1px solid rgba(0,229,255,0.3);
  border-radius: 12px;
  padding: 13px 14px;
  margin-bottom: 14px;
  font-size: 0.95rem;
}

input::placeholder,
textarea::placeholder {
  color: #8fbfd1;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: #f5c542;
  box-shadow:
    0 0 0 2px rgba(245,197,66,0.35),
    0 0 15px rgba(0,229,255,0.3);
}

/* =========================
   CHECKBOX & LABEL
========================= */
label {
  display: block;
  font-size: 0.9rem;
  margin-bottom: 6px;
  color: #d9ecf5;
}

input[type="checkbox"] {
  width: auto;
  margin-left: 6px;
  accent-color: #f5c542;
}

/* =========================
   ERROR
========================= */
.error {
  border-color: #ff5252 !important;
  box-shadow: 0 0 10px rgba(255,82,82,0.4);
}

/* =========================
   BUTTON
========================= */
button {
  width: 100%;
  margin-top: 18px;
  padding: 15px;
  border-radius: 16px;
  border: none;
  font-size: 1.05rem;
  font-weight: bold;
  color: #081b33;
  cursor: pointer;

  background: linear-gradient(
    135deg,
    #f5c542,
    #ffd977
  );

  box-shadow:
    0 0 25px rgba(245,197,66,0.6),
    inset 0 -3px 6px rgba(0,0,0,0.25);
}

button:hover {
  filter: brightness(1.05);
}

/* =========================
   MESSAGES
========================= */
.message {
  margin-top: 18px;
  font-size: 0.95rem;
}

.success {
  color: #7CFFB2;
  text-shadow: 0 0 10px rgba(124,255,178,0.5);
}

.fail {
  color: #ff8a80;
}

/* =========================
   DESKTOP ENHANCEMENT
========================= */
@media (min-width: 768px) {
  #signup {
    max-width: 900px;
    margin: 40px auto;
  }

  form {
    padding: 35px 40px 45px;
  }

  h3 {
    font-size: 1.15rem;
  }
}