:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-card-hover: #24344d;
  --bg-input: #0f172a;
  --border-color: #334155;
  --border-focus: #38bdf8;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent-color: #38bdf8;
  --accent-hover: #0ea5e9;
  --accent-gradient: linear-gradient(135deg, #38bdf8 0%, #6366f1 100%);
  --success-color: #10b981;
  --success-bg: rgba(16, 185, 129, 0.15);
  --warning-color: #f59e0b;
  --danger-color: #ef4444;
  --danger-bg: rgba(239, 68, 68, 0.15);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.35);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.5);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Навигационная панель */
.navbar {
  background-color: rgba(30, 41, 59, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 32px;
  height: 32px;
  background: var(--accent-gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-link:hover {
  color: var(--text-main);
  background-color: rgba(255, 255, 255, 0.05);
}

.nav-link.active {
  color: var(--accent-color);
  background-color: rgba(56, 189, 248, 0.12);
  font-weight: 600;
}

.nav-link.btn-logout {
  color: #f87171;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-link.btn-logout:hover {
  background-color: var(--danger-bg);
}

/* Контейнер страницы */
.page-container {
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  flex: 1;
}

/* Кнопки */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  opacity: 0.95;
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(56, 189, 248, 0.4);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-main);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-card-hover);
  border-color: var(--text-muted);
}

.btn-success {
  background-color: var(--success-color);
  color: white;
}

.btn-danger {
  background-color: var(--danger-color);
  color: white;
}

.btn-sm {
  padding: 0.4rem 0.75rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

/* Инпуты */
.input, .textarea, .select {
  width: 100%;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.7rem 1rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  outline: none;
  transition: var(--transition);
  font-family: inherit;
}

.input:focus, .textarea:focus, .select:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.textarea {
  min-height: 80px;
  resize: vertical;
}

/* Карточки */
.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

/* Заголовки и шапки */
.page-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.page-title {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.page-subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 0.2rem;
}

/* Навигатор дат */
.date-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius-md);
}

.date-bar input[type="date"] {
  background: transparent;
  border: none;
  color: var(--text-main);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.3rem 0.5rem;
  outline: none;
  cursor: pointer;
  color-scheme: dark;
}

/* Карточка авторизации */
.login-wrapper {
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.login-card {
  width: 100%;
  max-width: 420px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem;
  box-shadow: var(--shadow-lg);
  text-align: center;
}

.login-logo {
  width: 60px;
  height: 60px;
  background: var(--accent-gradient);
  border-radius: var(--radius-md);
  margin: 0 auto 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  box-shadow: 0 4px 20px rgba(56, 189, 248, 0.4);
}

.login-title {
  font-size: 1.45rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.login-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.75rem;
}

.form-group {
  margin-bottom: 1.2rem;
  text-align: left;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

/* Сетка уроков */
.lessons-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.lesson-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  transition: var(--transition);
  display: flex;
  gap: 1.25rem;
  position: relative;
}

.lesson-card:hover {
  border-color: rgba(56, 189, 248, 0.4);
  background-color: var(--bg-card-hover);
}

.lesson-card.done {
  border-color: rgba(16, 185, 129, 0.3);
  opacity: 0.85;
}

.lesson-card.done .lesson-subject {
  text-decoration: line-through;
  color: var(--text-muted);
}

.lesson-num-badge {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  background-color: var(--bg-input);
  border: 2px solid var(--accent-color);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--accent-color);
}

.lesson-time {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 0.2rem;
}

.lesson-content {
  flex: 1;
  min-width: 0;
}

.lesson-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
}

.lesson-subject {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
}

.lesson-section {
  margin-top: 0.5rem;
  padding: 0.6rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
}

.lesson-topic {
  background-color: rgba(255, 255, 255, 0.03);
  border-left: 3px solid #64748b;
  color: #cbd5e1;
}

.lesson-homework {
  background-color: rgba(56, 189, 248, 0.08);
  border-left: 3px solid var(--accent-color);
  color: #e0f2fe;
}

.lesson-section-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.2rem;
  color: var(--accent-color);
}

.lesson-topic .lesson-section-label {
  color: #94a3b8;
}

.lesson-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.done-checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  user-select: none;
  background-color: rgba(255, 255, 255, 0.05);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.done-checkbox-label:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.done-checkbox-label input {
  cursor: pointer;
}

/* Пустое состояние */
.empty-state {
  text-align: center;
  padding: 3.5rem 1rem;
  background-color: var(--bg-card);
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-lg);
}

.empty-icon {
  font-size: 3rem;
  margin-bottom: 0.8rem;
}

.empty-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.empty-desc {
  color: var(--text-muted);
  max-width: 400px;
  margin: 0 auto 1.5rem;
  font-size: 0.95rem;
}

/* Редактор формы уроков */
.editor-lesson-box {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-bottom: 1rem;
  transition: var(--transition);
}

.editor-lesson-box:focus-within {
  border-color: var(--border-focus);
}

.editor-lesson-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border-color);
}

.editor-num-title {
  font-weight: 700;
  color: var(--accent-color);
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.editor-row {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 1rem;
  margin-bottom: 0.8rem;
}

@media (max-width: 640px) {
  .editor-row {
    grid-template-columns: 1fr;
  }
}

/* Сетка недели */
.week-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.25rem;
}

.day-column {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.day-column-header {
  padding: 1rem 1.25rem;
  background-color: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.day-column-title {
  font-weight: 700;
  font-size: 1.1rem;
}

.day-column-date {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.day-column-body {
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  flex: 1;
}

.day-mini-lesson {
  padding: 0.65rem 0.85rem;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
}

.day-mini-lesson-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.3rem;
}

.day-mini-badge {
  font-weight: 700;
  color: var(--accent-color);
  font-size: 0.8rem;
}

.day-mini-subject {
  font-weight: 600;
  color: var(--text-main);
}

.day-mini-hw {
  color: #93c5fd;
  font-size: 0.82rem;
  margin-top: 0.2rem;
  white-space: pre-line;
}

/* Уведомления (Toast) */
.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  background-color: var(--bg-secondary);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.95rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  animation: slideIn 0.3s ease;
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--danger-color);
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Адаптивность для мобильных */
@media (max-width: 768px) {
  .nav-container {
    padding: 0.6rem 1rem;
    flex-wrap: wrap;
    gap: 0.6rem;
  }
  .nav-links {
    width: 100%;
    justify-content: space-around;
    padding-top: 0.4rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
  }
  .nav-link {
    font-size: 0.85rem;
    padding: 0.4rem 0.6rem;
  }
  .page-container {
    padding: 1rem 0.75rem 2.5rem;
  }
  .lesson-card {
    padding: 1rem;
    gap: 0.75rem;
  }
  .lesson-num-badge {
    width: 36px;
    height: 36px;
    font-size: 1rem;
  }
}