:root {
  --bg-1: #0b1220;
  --bg-2: #0f172a;
  --text: #e5edf7;
  --muted: #a8bad1;
  --line: rgba(148, 163, 184, 0.35);
  --card: rgba(15, 23, 42, 0.7);
  --brand: #22c55e;
  --brand-2: #0ea5e9;
  --primary: #0ea5e9;
  --text-main: #e5edf7;
  --text-muted: #a8bad1;
  --glass-border: rgba(148, 163, 184, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: "Segoe UI", Tahoma, sans-serif;
  text-align: center;
  color: var(--text);
  background:
    radial-gradient(1200px 500px at 10% -20%, rgba(34, 197, 94, 0.2), transparent),
    radial-gradient(1000px 500px at 100% 0%, rgba(14, 165, 233, 0.18), transparent),
    linear-gradient(160deg, var(--bg-1), var(--bg-2));
  min-height: 100%;
}

.container {
  width: min(1080px, 92%);
  margin: 0 auto;
}

.hero {
  padding: 64px 0 40px;
  border-bottom: 1px solid var(--line);
}

.top-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin: 0 0 14px;
}

.top-nav a {
  color: var(--text);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 12px;
  font-size: 13px;
  background: rgba(2, 6, 23, 0.35);
}

.top-nav a.active {
  color: #081019;
  border-color: transparent;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
}

.index-topbar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 12px auto 0;
  width: min(1080px, 92%);
}

.welcome-container-top {
  text-align: center;
  width: 100%;
}

.moving-text {
  margin: 0;
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.sidebar-toggle {
  position: fixed;
  top: 15px;
  left: 10px;
  z-index: 9999;
  background: rgba(6, 11, 24, 0.2);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.8);
  padding: 10px 15px;
  border-radius: 8px;
  cursor: pointer;
  backdrop-filter: blur(5px);
  transition: all 0.3s ease;
}

.sidebar-toggle:hover {
  background: var(--primary);
  transform: scale(1.1);
  box-shadow: 0 0 15px var(--primary);
}

.sidebar {
  position: fixed;
  top: 0;
  left: -280px;
  width: 280px;
  height: 100vh;
  background: linear-gradient(180deg, rgba(10, 15, 30, 0.95), rgba(15, 20, 40, 0.95));
  backdrop-filter: blur(20px);
  border-right: 1px solid var(--glass-border);
  box-shadow: 5px 0 25px rgba(0, 168, 255, 0.15);
  z-index: 9999;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.sidebar.active {
  left: 0;
  box-shadow: 0 0 35px rgba(0, 168, 255, 0.2);
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 10px;
  border-bottom: 2px solid var(--primary);
  background: linear-gradient(135deg, rgba(0, 168, 255, 0.1), transparent);
}

.brand-flex {
  display: flex;
  align-items: center;
  gap: 10px;
}

.sidebar-logo {
  width: auto;
  height: 80px;
  filter: drop-shadow(0 2px 8px rgba(0, 168, 255, 0.3));
}

.close-sidebar {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: 0.3s;
}

.close-sidebar:hover {
  color: var(--primary);
  transform: rotate(90deg);
}

.sidebar-menu {
  display: block;
}

.sidebar-links {
  list-style: none;
  padding: 10px 0;
  margin: 0;
  flex-grow: 1;
}

.sidebar-links li {
  list-style: none;
}

.sidebar-links li a {
  display: flex;
  align-items: center;
  padding: 12px 15px;
  color: var(--text-main);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  gap: 15px;
  border-left: 4px solid transparent;
  position: relative;
}

.sidebar-links li a:hover {
  background: rgba(0, 168, 255, 0.15);
  color: var(--primary);
  border-left: 4px solid var(--primary);
  padding-left: 20px;
  transform: translateX(3px);
}

.sidebar-links li a i {
  width: 22px;
  text-align: center;
  font-size: 1.1rem;
}

.divider-menu {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--glass-border), transparent);
  margin: 8px 0;
}

.sidebar-footer {
  padding: 20px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-muted);
  border-top: 2px solid var(--glass-border);
  margin-top: auto;
  background: linear-gradient(180deg, transparent, rgba(0, 168, 255, 0.05));
}

.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 9998;
  opacity: 0;
  visibility: hidden;
  transition: 0.3s;
  backdrop-filter: blur(2px);
}

.sidebar-overlay.active {
  opacity: 1;
  visibility: visible;
}

.badge {
  display: inline-block;
  margin: 0 0 12px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1.2;
}

.subtitle {
  margin: 0 auto;
  max-width: 760px;
  color: var(--muted);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 20px;
}

.section {
  padding: 28px 0;
}

h2 {
  margin: 0 0 14px;
  font-size: clamp(20px, 3.2vw, 30px);
}

.section-text {
  margin: 0 0 12px;
  color: var(--muted);
}

.grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
  backdrop-filter: blur(8px);
}

.card h3 {
  margin: 0 0 10px;
}

.card p,
.card li {
  color: var(--muted);
  line-height: 1.5;
}

.card ul {
  margin: 0 0 14px;
  padding-left: 0;
  list-style-position: inside;
}

.card ol {
  margin: 0 0 14px;
  padding-left: 0;
  list-style-position: inside;
}

.card-compact {
  min-height: 180px;
}

.btn {
  display: inline-block;
  text-decoration: none;
  border-radius: 10px;
  padding: 10px 14px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
}

.btn[aria-disabled="true"] {
  pointer-events: none;
  opacity: 0.75;
}

.btn-primary {
  color: #081019;
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
}

.btn-ghost {
  color: var(--text);
  border-color: var(--line);
  background: rgba(2, 6, 23, 0.35);
}

.btn-small {
  color: #081019;
  background: linear-gradient(90deg, #38bdf8, #22c55e);
  padding: 8px 12px;
  font-size: 14px;
}

.form-card {
  max-width: 620px;
  margin-inline: auto;
}

form {
  display: grid;
  gap: 10px;
}

label {
  font-size: 14px;
  color: var(--muted);
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 11px 12px;
  text-align: center;
  color: var(--text);
  background: rgba(15, 23, 42, 0.9);
}

textarea {
  min-height: 104px;
  resize: vertical;
}

.btn-block {
  width: 100%;
}

.hint {
  margin: 12px 0 0;
  font-size: 14px;
  color: var(--muted);
}

.hint a {
  color: #8dd6ff;
}

.form-msg {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.45;
}

.form-msg.is-info {
  background: rgba(14, 165, 233, 0.12);
  color: #ccecff;
}

.form-msg.is-success {
  background: rgba(34, 197, 94, 0.15);
  border-color: rgba(34, 197, 94, 0.45);
  color: #d8ffe8;
}

.form-msg.is-error {
  background: rgba(239, 68, 68, 0.16);
  border-color: rgba(239, 68, 68, 0.5);
  color: #ffd9d9;
}

.join-session-bar {
  margin: 10px auto 0;
  width: min(1080px, 92%);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: rgba(2, 6, 23, 0.45);
  color: var(--text);
  flex-wrap: wrap;
}

.btn-session-logout {
  padding: 6px 12px;
  font-size: 13px;
}

.footer {
  padding: 24px 0 34px;
  border-top: 1px solid var(--line);
}

.footer p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 640px) {
  .hero {
    padding-top: 42px;
  }
}