/* --- LeetCode Inspired Modern UI --- */
:root {
  --primary: #262626;
  --primary-light: #fff;
  --accent: #ffa116;
  --accent-dark: #ff9800;
  --blue: #3578e5;
  --danger: #e53935;
  --bg: #f7f8fa;
  --card-bg: #fff;
  --text: #23272f;
  --muted: #7a8599;
  --border: #e6eaf1;
  --radius: 16px;
  --shadow: 0 4px 24px rgba(38, 40, 64, 0.08);
  --shadow-hover: 0 8px 32px rgba(38, 40, 64, 0.13);
  --transition: 0.22s cubic-bezier(.4,0,.2,1);
}
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', 'Roboto', 'Inter', Arial, sans-serif;
  margin: 0;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 0 24px;
  box-sizing: border-box;
}
.tasks-list {
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin: 48px -25%;
  align-items: stretch;
}
.task-row {
  display: flex;
  align-items: center;
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow);
  padding: 28px 32px;
  transition: box-shadow var(--transition), background var(--transition), border var(--transition), transform 0.18s;
  cursor: pointer;
  min-height: 64px;
  animation: fadeInUp 0.7s cubic-bezier(.4,0,.2,1);
  margin-bottom: 0;
}
.task-row:hover {
  box-shadow: var(--shadow-hover);
  background: #fffbe6;
  border-color: var(--accent);
  transform: translateY(-2px) scale(1.01);
}
.task-row .task-meta {
  min-width: 140px;
  display: flex;
  gap: 8px;
  align-items: center;
}
.task-row .task-title {
  font-size: 1.13rem;
  font-weight: 600;
  margin: 0 18px 0 0;
  flex: 1;
  color: var(--primary);
  letter-spacing: 0.2px;
}
.task-row .btn {
  margin-left: 18px;
  min-width: 110px;
  border-radius: 10px;
  padding: 10px 28px;
  background: linear-gradient(90deg, var(--accent) 60%, var(--accent-dark) 100%);
  color: #fff;
  border: none;
  font-weight: 600;
  font-size: 1.05rem;
  transition: box-shadow var(--transition), background var(--transition), color var(--transition), transform 0.15s;
  box-shadow: 0 2px 8px rgba(255, 161, 22, 0.10);
}
.task-row .btn:hover, .task-row .btn:focus {
  background: linear-gradient(90deg, var(--accent-dark) 60%, var(--accent) 100%);
  color: #fff;
  box-shadow: 0 4px 16px rgba(255, 161, 22, 0.13);
  transform: scale(1.04);
}
/* --- Карточки и модалки --- */
.task-card, .profile-card, .modal-content {
  background: #fff;
  border-radius: var(--radius);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow);
  padding: 36px 32px 22px 32px;
  display: flex;
  flex-direction: column;
  min-height: 120px;
  margin-bottom: 0;
  animation: fadeInUp 0.7s cubic-bezier(.4,0,.2,1);
}
/* --- Кнопки --- */
.btn, .header-btn {
  background: linear-gradient(90deg, var(--accent) 60%, var(--accent-dark) 100%);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 12px 32px;
  font-size: 1.08rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border var(--transition), transform 0.15s;
  box-shadow: 0 2px 8px rgba(255, 161, 22, 0.10);
}
.btn:hover, .header-btn:hover, .btn:focus, .header-btn:focus {
  background: linear-gradient(90deg, var(--accent-dark) 60%, var(--accent) 100%);
  color: #fff;
  box-shadow: 0 4px 16px rgba(255, 161, 22, 0.13);
  transform: scale(1.04);
}
/* --- Инпуты --- */
input[type="text"], input[type="email"], input[type="password"] {
  background: #fff;
  color: var(--primary);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 1.08em;
  margin-bottom: 14px;
  outline: none;
  transition: border var(--transition), background var(--transition);
  box-shadow: none;
}
input[type="text"]:focus, input[type="email"]:focus, input[type="password"]:focus {
  border: 2px solid var(--accent);
  background: #fffbe6;
}
/* --- Бейджи --- */
.badge {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 8px;
  font-size: 0.98em;
  font-weight: 600;
  color: #fff;
  margin-right: 6px;
  letter-spacing: 0.5px;
  background: var(--blue);
  box-shadow: 0 1px 4px rgba(53, 120, 229, 0.08);
  user-select: none;
}
.badge.math { background: var(--blue); }
.badge.physics { background: #ffb300; color: #23232a; }
.badge.easy { background: #43a047; }
.badge.medium { background: #fbc02d; color: #23232a; }
.badge.hard { background: #d32f2f; }
/* --- Современные модалки входа и регистрации --- */
.modal {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 1000;
  background: rgba(0,0,0,0.18);
  display: none;
  align-items: center;
  justify-content: center;
}
.modal[style*="flex"], .modal[style*="block"] {
  display: flex !important;
}
.modal-content {
  background: #fff;
  border-radius: var(--radius);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow);
  padding: 36px 32px 22px 32px;
  max-width: 360px;
  width: 100%;
  position: relative;
  animation: scaleIn 0.5s cubic-bezier(.4,0,.2,1);
  transition: box-shadow 0.2s;
}
body.dark .modal-content {
  background: #23232a;
  border-color: #333;
}
.close {
  position: absolute;
  right: 18px;
  top: 12px;
  font-size: 1.5em;
  color: #888;
  cursor: pointer;
  transition: color var(--transition), transform 0.15s;
  border-radius: 50%;
  padding: 2px 8px;
  background: #fff;
  border: 1.5px solid #eee;
  box-shadow: none;
}
body.dark .close {
  background: #23232a;
  color: #fff;
  border-color: #555;
}
.close:hover {
  color: var(--danger);
  background: #fffbe6;
  transform: scale(1.15) rotate(8deg);
}
body.dark .close:hover {
  background: #181a1b;
}
/* --- Ошибки и успехи --- */
#loginMessageModal, #registerMessageModal {
  margin-top: 10px;
  min-height: 1.5em;
}
.success-message {
  color: #fff;
  background: var(--accent);
  padding: 10px;
  border-radius: 8px;
  margin-top: 10px;
  text-align: center;
  font-weight: 600;
  font-size: 1.05em;
}
.error-message {
  color: #fff;
  background: var(--danger);
  padding: 10px;
  border-radius: 8px;
  margin-top: 10px;
  text-align: center;
  font-weight: 600;
  font-size: 1.05em;
}
/* --- Темная тема --- */
body.dark {
  background: #181a1b;
  color: #f3f3f3;
}
body.dark .container,
body.dark .task-card,
body.dark .profile-card,
body.dark .modal-content {
  background: #23232a;
  color: #f3f3f3;
  border-color: #333;
}
body.dark .task-row {
  background: #23232a;
  color: #f3f3f3;
  border-color: #333;
}
body.dark .task-row:hover {
  background: #232b3a;
  border-color: var(--accent);
}
body.dark .task-row .task-title {
  color: #fff;
}
body.dark .btn, body.dark .header-btn {
  background: linear-gradient(90deg, #444 60%, #222 100%);
  color: #fff;
  border: none;
}
body.dark .btn:hover, body.dark .header-btn:hover, body.dark .btn:focus, body.dark .header-btn:focus {
  background: linear-gradient(90deg, var(--accent) 60%, var(--accent-dark) 100%);
  color: #fff;
  border: none;
}
body.dark input[type="text"],
body.dark input[type="email"],
body.dark input[type="password"] {
  background: #23232a;
  color: #fff;
  border: 1.5px solid #555;
}
body.dark input[type="text"]:focus,
body.dark input[type="email"]:focus,
body.dark input[type="password"]:focus {
  border: 2px solid var(--accent);
  background: #23232a;
}
body.dark .badge {
  background: var(--blue);
  color: #fff;
}
body.dark .badge.physics { background: #ffb300; color: #23232a; }
body.dark .badge.medium { background: #fbc02d; color: #23232a; }
body.dark .badge.hard { background: #d32f2f; }
body.dark .close {
  background: #23232a;
  color: #fff;
  border-color: #555;
}
body.dark .close:hover {
  background: #181a1b;
  color: var(--danger);
}
body.dark .success-message {
  background: var(--accent);
  color: #fff;
}
body.dark .error-message {
  background: var(--danger);
  color: #fff;
}
/* --- LeetCode Inspired Layout --- */
.leetcode-header {
  position: sticky;
  top: 0;
  width: 100%;
  background: #fff;
  box-shadow: 0 2px 12px rgba(38,40,64,0.07);
  z-index: 100;
  border-bottom: 1.5px solid var(--border);
}
body.dark .leetcode-header {
  background: #23232a;
  box-shadow: 0 2px 12px rgba(0,0,0,0.22);
  border-bottom: 1.5px solid #333;
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 32px;
}
.header-left {
  display: flex;
  align-items: center;
  gap: 18px;
}
.logo {
  font-family: 'Montserrat', 'Segoe UI', Arial, sans-serif;
  font-weight: 900;
  font-size: 2rem;
  letter-spacing: 2px;
  color: var(--accent);
  user-select: none;
  text-shadow: 0 2px 8px rgba(255,161,22,0.08);
}
.header-nav {
  display: flex;
  align-items: center;
  gap: 18px;
}
.leetcode-main {
  min-height: 80vh;
  padding-top: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
}
.leetcode-footer {
  width: 100%;
  background: #fff;
  border-top: 1.5px solid var(--border);
  padding: 18px 0 12px 0;
  margin-top: 48px;
}
body.dark .leetcode-footer {
  background: #23232a;
  border-top: 1.5px solid #333;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  font-size: 1.05em;
  color: var(--muted);
  padding: 0 32px;
}
/* --- Адаптивность --- */
@media (max-width: 700px) {
  .container { max-width: 98vw; padding: 0 4vw; }
  .task-card, .profile-card, .modal-content { padding: 14px 6px 10px 6px; }
  .task-row { padding: 12px 4px; }
  .header-inner, .footer-inner { padding: 0 8px; }
  .leetcode-main { padding-top: 16px; }
}
/* --- Анимации --- */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.85); }
  to { opacity: 1; transform: scale(1); }
}
/* --- LeetCode Registration Form --- */
.register-form-leetcode {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 8px;
  margin-top: 4px;
}
.register-title {
  font-size: 1.45em;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
  text-align: center;
  letter-spacing: 0.5px;
}
.input-group {
  display: flex;
  align-items: center;
  background: #f7f8fa;
  border-radius: 8px;
  border: 1.5px solid var(--border);
  padding: 0 10px;
  margin-bottom: 0;
  transition: border var(--transition), background var(--transition);
}
.input-group:focus-within {
  border: 2px solid var(--accent);
  background: #fffbe6;
}
.input-icon {
  font-size: 1.18em;
  margin-right: 8px;
  color: var(--muted);
  user-select: none;
}
.register-form-leetcode input[type="text"],
.register-form-leetcode input[type="email"],
.register-form-leetcode input[type="password"] {
  border: none;
  background: transparent;
  outline: none;
  font-size: 1.08em;
  padding: 12px 0;
  flex: 1;
  color: var(--primary);
  margin-bottom: 0;
}
body.dark .register-form-leetcode .input-group {
  background: #23232a;
  border-color: #333;
}
body.dark .register-form-leetcode input[type="text"],
body.dark .register-form-leetcode input[type="email"],
body.dark .register-form-leetcode input[type="password"] {
  color: #fff;
}
.btn-lg {
  font-size: 1.13em;
  padding: 14px 0;
  border-radius: 12px;
  margin-top: 8px;
  font-weight: 700;
}
.register-hint {
  text-align: center;
  color: var(--muted);
  font-size: 1em;
  margin-top: 2px;
}
.register-hint a {
  color: var(--accent);
  text-decoration: underline;
  cursor: pointer;
  font-weight: 600;
  transition: color var(--transition);
}
.register-hint a:hover {
  color: var(--blue);
}
.solved-link {
  color: var(--blue);
  text-decoration: underline;
  cursor: pointer;
  font-weight: 600;
  transition: color var(--transition);
}
.solved-link:hover {
  color: var(--accent);
}
body.dark .solved-link {
  color: #8ab4f8;
}
body.dark .solved-link:hover {
  color: var(--accent);
}