/* ======================================================
   1. RESET + BASE (DÙNG CHUNG)
====================================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    min-height: 100vh;
    background: #436AEC;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 16px;
}

/* ======================================================
   2. LAYOUT CHUNG (KHÔNG ĐƯỢC PHÁ)
====================================================== */
.container {
    width: 100%;
    max-width: 420px;
    margin: 0 auto;
    padding: 12px;
}

.card {
    background: #fff;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

/* ======================================================
   3. COMPONENT DÙNG CHUNG
====================================================== */

/* ----- TITLE ----- */
.title {
    font-size: 24px;
    text-align: center;
    margin-bottom: 16px;
}

/* ----- INPUT ----- */
.input-group {
    margin-bottom: 14px;
}

.input-wrapper {
    position: relative;
}

input {
    width: 100%;
    padding: 12px 40px 12px 12px;
    border-radius: 8px;
    border: 1px solid #ccc;
    font-size: 16px;
}

/* ----- TOGGLE EYE ----- */
.toggle {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
}

/* ----- BUTTON (BTN + SUBJECT BTN) ----- */
.btn,
.subject-btn {
    display: block;
    width: 100%;
    padding: 14px;
    border-radius: 10px;
    border: none;
    background: #5fc462;
    color: #fff;
    font-size: 18px;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    margin-bottom: 10px;

    box-shadow:
        0 4px 0 #24792B,
        0 8px 14px rgba(0,0,0,0.25);

    transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.btn:active,
.subject-btn:active {
    transform: translateY(3px);
    box-shadow:
        0 2px 0 #24792B,
        0 4px 6px rgba(0,0,0,0.2);
}

/* ----- LINK ----- */
.link {
    display: block;
    text-align: center;
    color: #4a90ff;
    text-decoration: none;
    margin-top: 6px;
}

/* ----- FLASH MESSAGE ----- */
.flash {
    text-align: center;
    margin-bottom: 10px;
    font-size: 14px;
}
.flash.error { color: red; }
.flash.success { color: green; }

/* ======================================================
   4. PAGE MODULE – LOGIN (GIỮA TOÀN BỘ)
====================================================== */
.login-card {
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ======================================================
   5. PAGE MODULE – SUBJECT (CHỌN MÔN)
====================================================== */
.subject-page {
    display: block; /* chảy top-down tự nhiên */
}

.subject-footer {
    margin-top: 6px;      /* sát cụm trên */
    padding-bottom: 12px;
}

/* ======================================================
   6. PAGE MODULE – CHOOSE QUIZ (CHỌN ĐỀ)
====================================================== */
.choose-quiz-page {
    display: block;
}

.choose-quiz-footer {
    margin-top: 6px;
    padding-bottom: 12px;
}
/* ============admin page================ */
.admin-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 20px 0;
}

.admin-actions a {
  padding: 14px;
  background: #111;
  color: #fff;
  text-decoration: none;
  border-radius: 8px;
  text-align: center;
  font-weight: 600;
}

#=============GIAO DIỆN TRANG ADMIN===========
/* ================= ADMIN PANEL ================= */

.admin-container {
  max-width: 1100px;
  margin: 30px auto;
  padding: 0 16px;
}

/* ----- CARD ----- */
.admin-card {
  background: #ffffff;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 24px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.06);
  overflow: visible;
}


.admin-card h3 {
  margin-top: 0;
  margin-bottom: 16px;
  font-size: 18px;
  border-bottom: 1px solid #eee;
  padding-bottom: 8px;
}

/* ----- FORM ----- */
.admin-card label {
  display: block;
  margin-top: 12px;
  font-weight: 600;
}

.admin-card input,
.admin-card select,
.admin-card textarea {
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid #ddd;
  font-size: 14px;
}

.admin-card textarea {
  resize: vertical;
  min-height: 120px;
}

/* ----- BUTTON ----- */
.btn {
  display: inline-block;
  margin-top: 14px;
  padding: 10px 16px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-weight: 600;
}

.btn-primary {
  background: #2563eb;
  color: #fff;
}

.btn-primary:hover {
  background: #1d4ed8;
}

.btn-danger {
  background: #dc2626;
  color: #fff;
}

.btn-danger:hover {
  background: #b91c1c;
}

/* ----- TABLE ----- */
.admin-card table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}

.admin-card table th,
.admin-card table td {
  padding: 10px;
  border-bottom: 1px solid #eee;
  text-align: left;
  font-size: 14px;
}

.admin-card table th {
  background: #f9fafb;
  font-weight: 700;
}

/* ----- QUESTION LIST ----- */
.question-item {
  padding: 12px;
  border-radius: 8px;
  background: #f9fafb;
  margin-bottom: 12px;
}

.question-item ul {
  margin: 8px 0 0 16px;
}

/* ----- FLASH MESSAGE ----- */
.flash.success {
  background: #ecfdf5;
  color: #065f46;
  padding: 10px;
  border-radius: 8px;
  margin-bottom: 16px;
}

.flash.error {
  background: #fef2f2;
  color: #991b1b;
  padding: 10px;
  border-radius: 8px;
  margin-bottom: 16px;
}
/* ===== FIX SELECT DROPDOWN BỊ CHE ===== */
.admin-card select {
  position: relative;
  z-index: 10;
}