:root {
  --dark: #20332d;
  --dark-light: #365349;
  --paper: #f5f4ef;
  --white: #fffefa;
  --ink: #202724;
  --muted: #6f7973;
  --accent: #dd6a43;
  --green: #6f9b59;
  --green-light: #e9f2e3;
  --line: #d9ddd5;
  --yellow: #fff5d4;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Arial, sans-serif;
}

button,
input,
textarea {
  font: inherit;
}

/* Экран входа */

.login-page {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 48% 52%;
}

.intro {
  min-height: 100vh;
  padding: 42px 72px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--dark);
  color: white;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  color: inherit;
  font-size: 20px;
  font-weight: 700;
  text-decoration: none;
}

.brand-mark {
  width: 29px;
  height: 29px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--accent);
  font-family: Georgia, serif;
}

.intro-text {
  max-width: 510px;
}

.eyebrow {
  margin: 0 0 12px;
  color: #83928a;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1.5px;
}

.intro h1 {
  margin: 0 0 24px;
  font-family: Georgia, serif;
  font-size: clamp(42px, 5vw, 72px);
  line-height: 1.04;
  letter-spacing: -2px;
}

.intro h1 span {
  color: #ef9b78;
}

.intro-text > p:last-child {
  max-width: 410px;
  color: #c7d0ca;
  font-size: 15px;
  line-height: 1.7;
}

.steps {
  display: flex;
  gap: 22px;
  margin: 0;
  padding: 20px 0 0;
  border-top: 1px solid #52645c;
  list-style: none;
  flex-wrap: wrap;
}

.steps li {
  color: #d7ded9;
  font-size: 12px;
}

.steps b {
  margin-right: 6px;
  color: #ed9875;
  font-size: 11px;
}

.login-area {
  display: grid;
  place-items: center;
  padding: 30px;
}

.login-card {
  width: min(410px, 100%);
}

.login-card h2 {
  margin: 0;
  font-family: Georgia, serif;
  font-size: 39px;
  letter-spacing: -1.4px;
}

.login-description {
  margin: 13px 0 30px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

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

label {
  display: grid;
  gap: 8px;
  color: #4c5751;
  font-size: 11px;
  font-weight: 700;
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--white);
  color: var(--ink);
  outline: none;
}

input {
  padding: 13px 14px;
  font-size: 14px;
}

input:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(221, 106, 67, 0.14);
}

form button,
.primary-button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 0;
  border-radius: 4px;
  background: var(--accent);
  color: white;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
}

form button {
  margin-top: 5px;
  padding: 14px 17px;
}

form button:hover,
.primary-button:hover {
  background: #c75835;
}

form button span,
.primary-button span {
  font-size: 20px;
  line-height: 12px;
}

.demo-text {
  margin-top: 20px;
  color: #8a938d;
  font-size: 11px;
  line-height: 1.6;
  text-align: center;
}

/* Рабочая тетрадь */

.notebook {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 275px 1fr;
}

.sidebar {
  min-height: 100vh;
  padding: 30px 19px;
  display: flex;
  flex-direction: column;
  background: var(--dark);
  color: white;
}

.sidebar-label {
  margin: 48px 10px 7px;
  color: #91a399;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1.4px;
}

.sidebar h1 {
  margin: 0 10px 34px;
  font-family: Georgia, serif;
  font-size: 28px;
}

.notebook-navigation {
  display: grid;
  gap: 5px;
}

.navigation-title {
  margin: 0 10px 7px;
  color: #8fa298;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 1.2px;
}

.navigation-title.space-top {
  margin-top: 23px;
}

.task-navigation {
  width: 100%;
  padding: 10px 11px;
  display: flex;
  align-items: center;
  gap: 10px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: #cbd6cf;
  cursor: pointer;
  font-size: 12px;
  text-align: left;
}

.task-navigation.active {
  background: var(--dark-light);
  color: white;
  font-weight: 700;
}

.task-navigation.available {
  color: #f2f6f1;
}

.task-navigation:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.task-status {
  width: 20px;
  height: 20px;
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  border: 1px solid #72857b;
  border-radius: 50%;
  color: #aab8b0;
  font-size: 10px;
}

.task-status.completed {
  border-color: #9ecb80;
  background: #9ecb80;
  color: #294636;
  font-size: 12px;
  font-weight: 700;
}

.student-card {
  margin-top: auto;
  padding: 18px 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  border-top: 1px solid #4b6055;
}

.student-avatar {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: #a3c987;
  color: #294335;
  font-size: 11px;
  font-weight: 700;
}

.student-card strong {
  display: block;
  font-size: 11px;
}

.student-card small {
  display: block;
  margin-top: 3px;
  color: #9eaca5;
  font-size: 10px;
}

.student-card button {
  width: 27px;
  height: 27px;
  margin-left: auto;
  border: 1px solid #64766d;
  border-radius: 50%;
  background: transparent;
  color: white;
  cursor: pointer;
}

.notebook-content {
  width: min(1080px, 100%);
  margin: 0 auto;
  padding: 37px 55px 70px;
}

.notebook-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 29px;
}

.notebook-header h2 {
  margin: 0;
  font-family: Georgia, serif;
  font-size: 34px;
  letter-spacing: -1.2px;
}

.progress-block {
  min-width: 180px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
}

.progress-block strong {
  float: right;
  color: var(--accent);
}

.progress-track {
  height: 5px;
  margin-top: 9px;
  overflow: hidden;
  border-radius: 8px;
  background: #dfe3dc;
}

.progress-bar {
  height: 100%;
  border-radius: 8px;
  background: var(--accent);
  transition: width 0.25s ease;
}

.lecture-card {
  margin-bottom: 18px;
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 15px;
  border: 1px solid #cfe0c4;
  border-radius: 5px;
  background: var(--green-light);
}

.lecture-icon {
  width: 32px;
  height: 32px;
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: #b9d8a6;
  color: #36553d;
  font-weight: 700;
}

.lecture-card h3,
.task-card h3,
.course-summary h3 {
  margin: 0;
  font-size: 17px;
  letter-spacing: -0.3px;
}

.lecture-card p:last-child {
  margin: 5px 0 0;
  color: #5d7062;
  font-size: 12px;
  line-height: 1.5;
}

.lecture-card a {
  margin-left: auto;
  padding: 10px 12px;
  border-radius: 4px;
  background: #476451;
  color: white;
  font-size: 11px;
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.task-card {
  padding: 25px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--white);
}

.task-top {
  display: flex;
  align-items: flex-start;
  gap: 13px;
}

.task-top > div:nth-child(2) {
  flex: 1;
}

.task-number {
  width: 31px;
  height: 31px;
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: #496858;
  color: white;
  font-size: 12px;
  font-weight: 700;
}

.task-top .eyebrow {
  margin-bottom: 7px;
}

.task-badge {
  padding: 6px 9px;
  border-radius: 20px;
  background: #eceeea;
  color: #7d8782;
  font-size: 10px;
  font-weight: 700;
}

.task-badge.ready {
  background: #dcefd0;
  color: #457239;
}

.task-description {
  margin: 20px 0;
  padding-left: 44px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.task-description p {
  margin: 0 0 9px;
}

.task-label {
  padding-left: 44px;
}

.task-label textarea {
  min-height: 120px;
  margin-top: 2px;
  padding: 13px;
  resize: vertical;
  font-size: 13px;
  line-height: 1.55;
}

.task-footer {
  margin-top: 15px;
  padding-left: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
}

.task-footer > span {
  color: var(--muted);
  font-size: 11px;
}

.primary-button {
  min-width: 172px;
  padding: 12px 15px;
}

.primary-button:disabled {
  cursor: not-allowed;
  background: #b8c1bc;
}

.course-summary {
  margin-top: 23px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--white);
}

.summary-title {
  margin-bottom: 15px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
}

.summary-title .eyebrow {
  margin-bottom: 7px;
}

.summary-title > span {
  color: var(--accent);
  font-size: 10px;
  font-weight: 700;
}

.summary-item {
  min-height: 69px;
  padding: 13px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid #e4e6e1;
  opacity: 0.58;
}

.summary-item.ready {
  opacity: 1;
}

.summary-number {
  width: 27px;
  height: 27px;
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: #ecefe9;
  color: #76827b;
  font-size: 10px;
  font-weight: 700;
}

.summary-item.ready .summary-number {
  background: #dcefd0;
  color: #47733a;
}

.summary-item > div:nth-child(2) {
  flex: 1;
}

.summary-item strong {
  display: block;
  font-size: 12px;
}

.summary-item p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.45;
}

.summary-state {
  color: #85908a;
  font-size: 16px;
}

.summary-item.ready .summary-state {
  color: #5f963f;
  font-weight: 700;
}

/* Версия для телефона */

@media (max-width: 800px) {
  .login-page {
    display: block;
  }

  .intro {
    min-height: auto;
    padding: 28px 24px;
  }

  .intro-text {
    margin: 65px 0 30px;
  }

  .intro h1 {
    font-size: 44px;
  }

  .steps {
    display: none;
  }

  .login-area {
    min-height: 580px;
    padding: 40px 24px;
  }

  .notebook {
    display: block;
  }

  .sidebar {
    min-height: auto;
    padding: 20px;
  }

  .sidebar-label,
  .sidebar h1,
  .student-card,
  .navigation-title {
    display: none;
  }

  .notebook-navigation {
    display: flex;
    overflow-x: auto;
    margin-top: 16px;
  }

  .task-navigation {
    width: auto;
    white-space: nowrap;
  }

  .notebook-content {
    padding: 28px 17px 60px;
  }

  .notebook-header {
    display: block;
    margin-bottom: 25px;
  }

  .notebook-header h2 {
    font-size: 29px;
  }

  .progress-block {
    margin-top: 22px;
  }

  .lecture-card {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .lecture-card a {
    margin-left: 47px;
  }

  .task-card {
    padding: 20px;
  }

  .task-description,
  .task-label,
  .task-footer {
    padding-left: 0;
  }

  .task-footer {
    align-items: stretch;
    flex-direction: column;
  }

  .primary-button {
    width: 100%;
  }
}