/* Global reset */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #050816;
  --bg-alt: #0b1020;
  --card-bg: #0f172a;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.15);
  --danger: #f97373;
  --border-soft: rgba(148, 163, 184, 0.25);
  --radius-lg: 18px;
  --shadow-soft: 0 18px 40px rgba(15, 23, 42, 0.8);
  --transition-fast: 0.2s ease;
  --font-main: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

html, body {
  height: 100%;
}

body {
  font-family: var(--font-main);
  background: radial-gradient(circle at top, #1d293b 0, #020617 50%, #000 100%);
  color: var(--text);
}

/* Layout */

.app-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 8%;
  backdrop-filter: blur(18px);
  background: linear-gradient(to right, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.8));
  border-bottom: 1px solid var(--border-soft);
}

.logo {
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: 0.05em;
}

.logo span {
  color: var(--accent);
}

.nav-links a {
  margin-left: 1rem;
  text-decoration: none;
  color: var(--muted);
  font-size: 0.95rem;
  padding: 6px 12px;
  border-radius: 999px;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-links a:hover {
  background: rgba(15, 23, 42, 0.9);
  color: var(--text);
}

.nav-links a.active {
  background: var(--accent-soft);
  color: var(--accent);
}

.container {
  max-width: 1100px;
  margin: 24px auto 40px;
  padding: 0 8%;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1.4fr);
  gap: 32px;
  align-items: center;
  margin-bottom: 32px;
}

.hero h1 {
  font-size: clamp(2.1rem, 3vw, 2.7rem);
  margin-bottom: 8px;
}

.subtitle {
  color: var(--muted);
  margin-bottom: 12px;
}

.hero-actions {
  margin-top: 18px;
  display: flex;
  gap: 12px;
}

.hero-card {
  background: linear-gradient(135deg, #0f172a, #020617);
  border-radius: var(--radius-lg);
  padding: 18px 18px 16px;
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--border-soft);
}

.hero-card h2 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.timeline {
  list-style: none;
}

.timeline li {
  padding: 10px 0;
  border-bottom: 1px solid rgba(30, 64, 175, 0.4);
  font-size: 0.93rem;
}

.timeline li:last-child {
  border-bottom: none;
}

.timeline li span {
  display: block;
  font-size: 0.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

/* Cards & grid */

.card {
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.92));
  border-radius: var(--radius-lg);
  padding: 18px 18px 16px;
  margin-top: 18px;
  border: 1px solid var(--border-soft);
  box-shadow: var(--shadow-soft);
}

.card.soft {
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.7);
}

.card h2, .card h3 {
  font-size: 1.05rem;
  margin-bottom: 10px;
}

.card-header-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 20px;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  padding: 8px 16px;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast), color var(--transition-fast);
}

.btn.primary {
  background: radial-gradient(circle at top left, #38bdf8, #0ea5e9);
  color: #0b1120;
  box-shadow: 0 10px 25px rgba(56, 189, 248, 0.35);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 30px rgba(56, 189, 248, 0.5);
}

.btn.ghost {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent-soft);
}

.btn.ghost:hover {
  background: var(--accent-soft);
}

.btn.danger {
  background: rgba(248, 113, 113, 0.15);
  color: var(--danger);
  border: 1px solid rgba(248, 113, 113, 0.6);
}

.btn.small {
  font-size: 0.8rem;
  padding: 6px 12px;
}

/* Forms */

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 14px;
  margin-top: 8px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

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

label {
  font-size: 0.85rem;
  color: var(--muted);
}

input[type="text"],
input[type="number"] {
  background: rgba(15, 23, 42, 0.9);
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.5);
  padding: 8px 12px;
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  transition: border var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

input[type="text"]:focus,
input[type="number"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.6);
  background: rgba(15, 23, 42, 0.95);
}

/* Tables */

.table-wrapper {
  overflow-x: auto;
  margin-top: 10px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

thead {
  background: rgba(15, 23, 42, 0.9);
}

th, td {
  padding: 8px 10px;
  border-bottom: 1px solid rgba(30, 64, 175, 0.35);
}

th {
  text-align: left;
  color: var(--muted);
  font-weight: 500;
}

tbody tr:nth-child(even) {
  background: rgba(15, 23, 42, 0.6);
}

/* Text helpers */

.muted {
  color: var(--muted);
  font-size: 0.88rem;
  margin-top: 6px;
}

.result-block {
  margin-top: 10px;
  background: rgba(15, 23, 42, 0.9);
  border-radius: 12px;
  padding: 10px 12px;
  border: 1px dashed rgba(148, 163, 184, 0.4);
  font-size: 0.9rem;
}

.tree-view {
  margin-top: 10px;
  background: rgba(15, 23, 42, 0.9);
  border-radius: 12px;
  padding: 10px 12px;
  border: 1px solid rgba(30, 64, 175, 0.6);
  font-size: 0.85rem;
  max-height: 260px;
  overflow: auto;
}

/* Canvas */

.canvas-preview {
  margin-top: 10px;
  border-radius: 14px;
  border: 1px solid rgba(30, 64, 175, 0.7);
  background: radial-gradient(circle at top, #020617, #020617 45%, #000 100%);
}

/* Footer & banners */

.footer {
  text-align: center;
  padding: 16px 0 24px;
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid rgba(15, 23, 42, 0.8);
  margin-top: 20px;
}

.next-module-banner {
  margin-top: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 999px;
  background: radial-gradient(circle at left, rgba(56, 189, 248, 0.2), rgba(15, 23, 42, 0.9));
  border: 1px solid rgba(56, 189, 248, 0.4);
}

.next-module-banner p {
  font-size: 0.9rem;
}

/* Responsive */

@media (max-width: 800px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .container {
    padding: 0 16px;
  }

  .next-module-banner {
    flex-direction: column;
    align-items: flex-start;
  }
}