:root {
  --primary: #1769e0;
  --primary-dark: #0d4fae;
  --primary-light: #eaf3ff;
  --accent: #20a4f3;
  --bg: #f5f8fc;
  --white: #ffffff;
  --text: #172033;
  --muted: #718096;
  --border: #e5eaf1;
  --success: #159957;
  --danger: #dc3545;
  --warning: #f59e0b;
  --shadow: 0 8px 25px rgba(25, 55, 100, .08);
  --radius: 16px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Inter", sans-serif;
  background: var(--bg);
  color: var(--text);
}

button,
input,
select,
textarea {
  font-family: inherit;
}

button {
  cursor: pointer;
  border: 0;
}

.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.muted {
  color: var(--muted);
  line-height: 1.6;
}

.full {
  width: 100%;
}

/* AUTH */

.auth-screen {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 30px;
  background:
    radial-gradient(circle at top left, #dcecff, transparent 35%),
    linear-gradient(135deg, #f7fbff, #edf5ff);
}

.auth-card {
  width: min(470px, 100%);
  background: var(--white);
  padding: 38px;
  border-radius: 25px;
  box-shadow: 0 20px 60px rgba(20, 60, 110, .12);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.auth-brand {
  justify-content: center;
  margin-bottom: 30px;
}

.brand-icon {
  width: 45px;
  height: 45px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  display: grid;
  place-items: center;
  border-radius: 13px;
  font-weight: 800;
  font-size: 23px;
  box-shadow: 0 8px 18px rgba(23, 105, 224, .25);
}

.brand h1 {
  color: var(--primary);
}

.brand span {
  color: var(--muted);
  font-size: 12px;
}

.auth-form h2 {
  margin-bottom: 7px;
}

.auth-form > label,
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin: 18px 0 7px;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 12px 14px;
  outline: none;
  background: white;
  color: var(--text);
  transition: .2s;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(23, 105, 224, .1);
}

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

.primary-btn {
  background: var(--primary);
  color: white;
  padding: 13px 18px;
  border-radius: 11px;
  font-weight: 700;
  transition: .2s;
}

.primary-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.secondary-btn {
  background: var(--primary-light);
  color: var(--primary);
  padding: 11px 16px;
  border-radius: 10px;
  font-weight: 700;
}

.danger-btn {
  background: #fff0f1;
  color: var(--danger);
  padding: 11px 16px;
  border-radius: 10px;
  font-weight: 700;
}

.text-btn {
  background: transparent;
  color: var(--primary);
  padding: 12px;
  font-weight: 600;
}

.auth-links {
  display: flex;
  justify-content: space-between;
  margin-top: 16px;
}

.auth-links button {
  background: transparent;
  color: var(--primary);
  font-size: 13px;
}

.error-message {
  color: var(--danger);
  font-size: 13px;
  margin-top: 12px;
}

.success-message {
  color: var(--success);
  font-size: 13px;
  margin-top: 12px;
}

.demo-box {
  margin-top: 25px;
  padding: 14px;
  border-radius: 12px;
  background: #f5f8fc;
  font-size: 12px;
  line-height: 1.8;
}

.demo-code {
  margin: 18px 0;
  padding: 12px;
  text-align: center;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 10px;
  font-size: 13px;
}

.verification-code {
  display: flex;
  gap: 8px;
  margin-top: 22px;
}

.verification-code input {
  text-align: center;
  font-size: 22px;
  font-weight: 700;
}

.verify-icon,
.success-circle {
  margin: 0 auto 18px;
  width: 70px;
  height: 70px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: #e7f8ef;
  color: var(--success);
  font-size: 35px;
  font-weight: 800;
}

/* APP */

.app {
  min-height: 100vh;
  display: flex;
}

.sidebar {
  width: 260px;
  background: white;
  border-right: 1px solid var(--border);
  padding: 22px 15px;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 50;
  overflow-y: auto;
}

.sidebar-brand {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 5px 8px 24px;
}

.sidebar-brand strong {
  display: block;
  color: var(--primary);
  font-size: 18px;
}

.sidebar-brand small {
  color: var(--muted);
  font-size: 10px;
}

.user-mini {
  display: flex;
  gap: 10px;
  align-items: center;
  background: var(--primary-light);
  padding: 12px;
  border-radius: 13px;
  margin-bottom: 22px;
}

.user-mini strong {
  display: block;
  font-size: 12px;
}

.user-mini small {
  color: var(--muted);
  font-size: 10px;
}

.avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1b75e5, #42b6f5);
  color: white;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 800;
  flex-shrink: 0;
}

nav {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.nav-item {
  background: transparent;
  color: #596579;
  text-align: left;
  padding: 12px 13px;
  border-radius: 10px;
  font-size: 13px;
  font-weight: 600;
}

.nav-item:hover,
.nav-item.active {
  background: var(--primary-light);
  color: var(--primary);
}

.nav-item.logout {
  margin-top: 15px;
  color: var(--danger);
}

.main-content {
  margin-left: 260px;
  width: calc(100% - 260px);
  min-height: 100vh;
}

.topbar {
  height: 78px;
  background: white;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 30px;
  position: sticky;
  top: 0;
  z-index: 30;
}

.page-heading h2 {
  font-size: 20px;
}

.page-heading span {
  color: var(--muted);
  font-size: 12px;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 20px;
}

.icon-btn {
  width: 40px;
  height: 40px;
  background: #f5f8fc;
  border-radius: 10px;
  position: relative;
}

.notification-dot {
  position: absolute;
  width: 8px;
  height: 8px;
  background: #ff5c5c;
  border-radius: 50%;
  top: 7px;
  right: 8px;
}

.top-user {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 13px;
  font-weight: 600;
}

.menu-btn {
  display: none;
  background: transparent;
  font-size: 22px;
}

/* CONTENT */

#pageContent {
  padding: 30px;
  max-width: 1500px;
  margin: auto;
}

.welcome {
  background: linear-gradient(120deg, #1165db, #2ca8ef);
  color: white;
  padding: 28px;
  border-radius: 20px;
  margin-bottom: 25px;
  position: relative;
  overflow: hidden;
}

.welcome h1 {
  font-size: 25px;
  margin-bottom: 8px;
}

.welcome p {
  opacity: .88;
  font-size: 13px;
}

.grid {
  display: grid;
  gap: 18px;
}

.stats-grid {
  grid-template-columns: repeat(5, 1fr);
}

.two-grid {
  grid-template-columns: 1.3fr .7fr;
}

.three-grid {
  grid-template-columns: repeat(3, 1fr);
}

.card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}

.stat-card {
  min-height: 130px;
}

.stat-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.stat-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--primary-light);
  display: grid;
  place-items: center;
}

.stat-value {
  font-size: 26px;
  font-weight: 800;
  margin-top: 15px;
}

.stat-label {
  color: var(--muted);
  font-size: 12px;
}

.section-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 28px 0 15px;
}

.section-title h3 {
  font-size: 16px;
}

.session-card {
  background: linear-gradient(135deg, #f1f7ff, white);
}

.session-info {
  display: grid;
  gap: 12px;
  margin: 18px 0;
}

.info-line {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 13px;
}

.info-line span:first-child {
  width: 25px;
}

.progress {
  height: 9px;
  background: #e8edf4;
  border-radius: 20px;
  overflow: hidden;
  margin: 12px 0;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: inherit;
}

.quick-actions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.quick-action {
  padding: 15px;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 12px;
  text-align: left;
  font-weight: 600;
  font-size: 12px;
}

.quick-action:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* PAGE */

.page-header {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  align-items: center;
  margin-bottom: 22px;
}

.page-header h1 {
  font-size: 23px;
}

.page-header p {
  color: var(--muted);
  font-size: 13px;
  margin-top: 4px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.form-grid .full-width {
  grid-column: 1 / -1;
}

.form-actions {
  margin-top: 22px;
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
}

.chip {
  padding: 7px 11px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 30px;
  font-size: 11px;
  font-weight: 600;
}

.availability-list {
  display: grid;
  gap: 12px;
}

.availability-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 12px;
}

.day {
  font-weight: 700;
}

.time {
  color: var(--muted);
  font-size: 12px;
}

.badge {
  padding: 6px 10px;
  border-radius: 20px;
  font-size: 10px;
  font-weight: 700;
}

.badge.available {
  background: #e8f8ef;
  color: var(--success);
}

.badge.booked {
  background: #fff0f0;
  color: var(--danger);
}

.announcement {
  border-left: 4px solid var(--primary);
}

.announcement h3 {
  margin-bottom: 8px;
}

.announcement-meta {
  color: var(--muted);
  font-size: 11px;
  margin-bottom: 12px;
}

.announcement p {
  color: #5d6777;
  font-size: 13px;
  line-height: 1.6;
}

.schedule-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr auto;
  gap: 10px;
  align-items: center;
  padding: 15px;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
}

.schedule-row:last-child {
  border-bottom: 0;
}

/* CHAT */

.chat-container {
  height: calc(100vh - 140px);
  min-height: 550px;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: grid;
  grid-template-columns: 280px 1fr;
  overflow: hidden;
}

.chat-sidebar {
  border-right: 1px solid var(--border);
  padding: 15px;
}

.chat-person {
  display: flex;
  gap: 10px;
  padding: 12px;
  background: var(--primary-light);
  border-radius: 12px;
}

.chat-person small {
  color: var(--success);
}

.chat-main {
  display: flex;
  flex-direction: column;
}

.chat-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.chat-header strong {
  display: block;
}

.online {
  color: var(--success);
  font-size: 11px;
}

.messages {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.message {
  max-width: 70%;
  padding: 11px 14px;
  border-radius: 14px;
  font-size: 13px;
  line-height: 1.5;
}

.message.sent {
  align-self: flex-end;
  background: var(--primary);
  color: white;
  border-bottom-right-radius: 4px;
}

.message.received {
  align-self: flex-start;
  background: #f1f4f8;
  border-bottom-left-radius: 4px;
}

.message-time {
  display: block;
  font-size: 9px;
  opacity: .65;
  margin-top: 5px;
}

.chat-input {
  display: flex;
  gap: 10px;
  padding: 15px;
  border-top: 1px solid var(--border);
}

/* VIDEO */

.video-room {
  background: #101827;
  color: white;
  border-radius: 18px;
  min-height: 570px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.video-placeholder {
  text-align: center;
}

.video-avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1f80ed, #53b6f2);
  display: grid;
  place-items: center;
  font-size: 34px;
  font-weight: 800;
  margin: auto;
}

.video-controls {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
}

.video-controls button {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: #293345;
  color: white;
}

.video-controls .leave {
  background: var(--danger);
}

.session-details {
  margin-top: 18px;
}

/* TABLE */

.table-wrapper {
  overflow-x: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th,
.data-table td {
  padding: 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
}

.data-table th {
  color: var(--muted);
}

/* MODAL */

.modal {
  position: fixed;
  inset: 0;
  background: rgba(12, 25, 45, .45);
  display: grid;
  place-items: center;
  z-index: 100;
  padding: 20px;
}

.modal-content {
  background: white;
  width: min(550px, 100%);
  max-height: 90vh;
  overflow-y: auto;
  border-radius: 18px;
  padding: 25px;
  position: relative;
}

.modal-close {
  position: absolute;
  right: 18px;
  top: 15px;
  background: transparent;
  font-size: 25px;
}

/* RESPONSIVE */

@media (max-width: 1100px) {
  .stats-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .two-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 800px) {
  .sidebar {
    transform: translateX(-100%);
    transition: .25s;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main-content {
    margin-left: 0;
    width: 100%;
  }

  .menu-btn {
    display: block;
  }

  .topbar {
    padding: 0 16px;
    gap: 12px;
  }

  .top-user span {
    display: none;
  }

  #pageContent {
    padding: 18px;
  }

  .stats-grid,
  .three-grid {
    grid-template-columns: 1fr 1fr;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .form-grid .full-width {
    grid-column: auto;
  }

  .chat-container {
    grid-template-columns: 1fr;
  }

  .chat-sidebar {
    display: none;
  }

  .schedule-row {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 550px) {
  .auth-card {
    padding: 25px 20px;
  }

  .stats-grid,
  .three-grid {
    grid-template-columns: 1fr;
  }

  .quick-actions {
    grid-template-columns: 1fr;
  }

  .welcome h1 {
    font-size: 20px;
  }

  .page-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .verification-code {
    gap: 5px;
  }

  .verification-code input {
    padding: 10px 3px;
  }
}
/* Administrator monitoring addition */
.admin-login-link{margin-top:12px}.admin-badge{display:inline-block;background:#e9f7ef;color:#157347;border-radius:999px;padding:6px 10px;font-size:11px;font-weight:800;letter-spacing:.8px}.admin-screen{min-height:100vh;background:#f4f7f8}.admin-header{height:76px;background:#123d2b;color:#fff;display:flex;justify-content:space-between;align-items:center;padding:0 5vw;position:sticky;top:0;z-index:20}.admin-header .brand{display:flex;align-items:center;gap:12px}.admin-header .brand h1{margin:0}.admin-header .brand span{color:#d9eadf}.admin-main{max-width:1250px;margin:auto;padding:32px 5vw 70px}.admin-hero{background:linear-gradient(135deg,#123d2b,#28704e);color:#fff;border-radius:22px;padding:30px;margin-bottom:22px}.admin-hero h1{font-size:36px;margin:9px 0}.admin-hero p{color:#d9eadf}.admin-stat-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;margin-bottom:22px}.admin-users-panel{padding:23px}.admin-tools{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:20px}.admin-filters{display:flex;gap:10px;min-width:430px}.admin-user-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.admin-user-card{border:1px solid #e0e7e3;border-radius:16px;padding:18px;background:white}.admin-user-head{display:flex;align-items:center;gap:12px}.admin-user-head h3,.admin-user-head p{margin:0}.admin-user-head p{font-size:12px;color:#6b7770}.admin-user-head .role-chip{margin-left:auto}.role-chip{padding:5px 9px;border-radius:999px;font-size:10px;font-weight:800;text-transform:uppercase}.role-chip.student{background:#e7f2ff;color:#165d9c}.role-chip.mentor{background:#f1eaff;color:#6e3aa8}.admin-user-meta{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:16px 0}.admin-user-meta span{background:#f6f8f7;padding:9px;border-radius:9px;font-size:11px;color:#68736d}.admin-user-meta b{display:block;color:#223029;margin-bottom:3px}.admin-detail-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:18px 0}.admin-detail-grid>div{background:#f6f8f7;padding:12px;border-radius:10px}.admin-detail-grid p{margin:4px 0 0}.admin-view-bar{position:sticky;top:0;z-index:100;background:#123d2b;color:#fff;display:flex;justify-content:center;align-items:center;gap:24px;padding:11px 18px;box-shadow:0 4px 15px #0003}.admin-view-bar div{display:flex;gap:10px;align-items:center}.admin-view-bar span{font-size:13px;color:#d9eadf}.admin-view-bar button{background:#b8de8b;color:#123d2b;border:0;border-radius:9px;padding:9px 13px;font-weight:800}.admin-readonly input,.admin-readonly textarea,.admin-readonly select{pointer-events:none;opacity:.7}
@media(max-width:850px){.admin-stat-grid{grid-template-columns:repeat(2,1fr)}.admin-user-grid{grid-template-columns:1fr}.admin-tools{display:block}.admin-filters{min-width:0;margin-top:14px;display:grid}.admin-view-bar{display:grid;text-align:center;gap:7px}.admin-view-bar div{display:grid;gap:2px}.admin-hero h1{font-size:28px}.admin-user-meta{grid-template-columns:repeat(2,1fr)}}