:root {
  --bg: #0f172a;
  --surface: rgba(15, 23, 42, 0.75);
  --surface-light: rgba(30, 41, 59, 0.85);
  --accent: #ef7e3b;
  --accent-strong: #ea580c;
  --border: rgba(148, 163, 184, 0.3);
  --shadow: 0 24px 48px rgba(15, 23, 42, 0.5);
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --text-invert: #f8fafc;
  --success: #22c55e;
  --error: #ef4444;
  --font-family: "Outfit", system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  font-family: var(--font-family);
  background: var(--bg);
  color: var(--text-invert);
  line-height: 1.6;
  position: relative;
  overflow-x: hidden;
}

.background {
  position: fixed;
  inset: 0;
  background: radial-gradient(circle at 10% 20%, rgba(59, 130, 246, 0.18), transparent 55%),
    radial-gradient(circle at 80% 0%, rgba(236, 72, 153, 0.15), transparent 40%),
    linear-gradient(180deg, rgba(15, 23, 42, 0.95) 0%, rgba(15, 23, 42, 0.85) 100%);
  pointer-events: none;
  z-index: -1;
}

.hero {
  padding: clamp(2rem, 4vw, 3.5rem) clamp(1.5rem, 3vw, 3rem) 0;
}

.hero__inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  gap: 1.5rem;
}

.hero__title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  margin: 0;
  font-weight: 700;
}

.hero__subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: clamp(1.1rem, 2.6vw, 1.4rem);
  max-width: 680px;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.25rem;
  border-radius: 999px;
  border: 1px solid transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: var(--text-invert);
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  box-shadow: 0 10px 30px rgba(239, 126, 59, 0.35);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 40px rgba(239, 126, 59, 0.45);
}

.btn:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.btn--ghost {
  background: rgba(15, 23, 42, 0.4);
  border-color: rgba(148, 163, 184, 0.3);
  box-shadow: none;
}

.btn--ghost:hover {
  border-color: var(--accent);
}

.btn--small {
  padding: 0.5rem 0.9rem;
  font-size: 0.95rem;
}

.layout {
  display: grid;
  grid-template-columns: minmax(280px, 360px) minmax(320px, 1fr) minmax(340px, 1fr) minmax(260px, 320px);
  gap: clamp(1rem, 2vw, 1.75rem);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  max-width: 1440px;
  margin: 0 auto;
  align-items: start;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: clamp(1.25rem, 2.5vw, 1.75rem);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.panel__header {
  display: grid;
  gap: 0.35rem;
}

.panel__intro {
  color: var(--text-muted);
  margin: 0;
}

.panel--lesson,
.panel--practice {
  grid-column: span 1;
}

.panel--sidebar {
  grid-column: 1 / 2;
}

.panel--lesson {
  grid-column: 2 / 3;
}

.panel--practice {
  grid-column: 3 / 4;
}

.panel--tracker {
  grid-column: 4 / 5;
  background: var(--surface-light);
}

.filters {
  display: grid;
  gap: 0.75rem;
}

.filters__option {
  display: grid;
  gap: 0.35rem;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.filters__option select,
.filters__option input[type="search"] {
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid var(--border);
  color: var(--text-invert);
  padding: 0.55rem 0.75rem;
  border-radius: 12px;
  font: inherit;
}

.filters__option--search input {
  width: 100%;
}

.technique-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

.technique-list__button {
  width: 100%;
  text-align: left;
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid transparent;
  color: inherit;
  padding: 0.85rem 1rem;
  border-radius: 16px;
  display: grid;
  gap: 0.35rem;
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.technique-list__button:hover,
.technique-list__button[aria-pressed="true"] {
  border-color: var(--accent);
  box-shadow: 0 12px 30px rgba(239, 126, 59, 0.2);
  transform: translateY(-2px);
}

.technique-list__button span {
  display: block;
}

.technique-list__difficulty {
  color: var(--accent);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.lesson {
  display: grid;
  gap: 1.5rem;
}

.lesson__header {
  display: grid;
  gap: 0.5rem;
  padding: 1rem;
  background: rgba(15, 23, 42, 0.5);
  border-radius: 18px;
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.lesson__mantra {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
  color: var(--accent);
}

.lesson__summary {
  margin: 0;
  color: var(--text-muted);
}

.lesson__section h3 {
  margin-top: 0;
}

.lesson__steps,
.lesson__anchors,
.lesson__examples {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

.lesson__steps li {
  padding: 0.75rem 1rem;
  background: rgba(15, 23, 42, 0.45);
  border-radius: 12px;
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.lesson__anchors {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.lesson__anchors li {
  padding: 0.35rem 0.75rem;
  background: rgba(239, 126, 59, 0.2);
  color: var(--accent);
  border-radius: 999px;
  font-size: 0.85rem;
}

.example {
  padding: 1rem;
  border-radius: 16px;
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid rgba(148, 163, 184, 0.2);
  display: grid;
  gap: 0.75rem;
}

.example__title {
  margin: 0;
  font-size: 1.05rem;
}

.example__walkthrough {
  margin: 0;
  padding-left: 1.25rem;
  display: grid;
  gap: 0.35rem;
}

.example__result {
  margin: 0;
  color: var(--accent);
  font-weight: 600;
}

.practice-setup {
  display: grid;
  gap: 1.5rem;
}

.practice-setup fieldset {
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: 16px;
  padding: 1rem;
  display: grid;
  gap: 0.75rem;
}

.practice-setup__grid {
  display: grid;
  gap: 0.75rem;
}

.practice-setup__chip {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.25rem;
  padding: 0.75rem 1rem;
  background: rgba(15, 23, 42, 0.45);
  border-radius: 14px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.practice-setup__chip:hover,
.practice-setup__chip[aria-pressed="true"] {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.practice-setup__chip small {
  color: var(--text-muted);
}

.practice-setup__actions {
  display: flex;
  gap: 0.75rem;
}

.practice-session[hidden] {
  display: none;
}

.practice-session__header {
  display: grid;
  gap: 0.35rem;
}

.practice-session__queue {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.practice-session__item {
  padding: 1rem;
  border-radius: 16px;
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid rgba(148, 163, 184, 0.2);
  display: grid;
  gap: 0.75rem;
}

.practice-session__form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.practice-session__form input {
  flex: 1 1 140px;
  padding: 0.65rem 0.85rem;
  border-radius: 12px;
  border: 1px solid rgba(148, 163, 184, 0.3);
  background: rgba(15, 23, 42, 0.6);
  color: var(--text-invert);
  font: inherit;
}

.practice-session__feedback {
  border-top: 1px solid rgba(148, 163, 184, 0.25);
  padding-top: 0.75rem;
  display: grid;
  gap: 0.5rem;
}

.practice-session__status {
  margin: 0;
  font-weight: 600;
}

.practice-session__status[data-state="correct"] {
  color: var(--success);
}

.practice-session__status[data-state="incorrect"] {
  color: var(--error);
}

.practice-session__steps {
  margin: 0;
  padding-left: 1.25rem;
  display: grid;
  gap: 0.25rem;
}

.practice-session__progress {
  color: var(--text-muted);
}

.tracker {
  display: grid;
  gap: 1.25rem;
}

.tracker__summary {
  display: grid;
  gap: 0.5rem;
}

.tracker__notes textarea {
  width: 100%;
  min-height: 120px;
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: 12px;
  padding: 0.75rem;
  color: var(--text-invert);
  font: inherit;
}

.history {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.65rem;
}

.history li {
  padding: 0.75rem 1rem;
  background: rgba(15, 23, 42, 0.45);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 14px;
  display: grid;
  gap: 0.25rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 1280px) {
  .layout {
    grid-template-columns: minmax(280px, 1fr) minmax(320px, 1fr);
    grid-template-areas:
      "sidebar lesson"
      "practice tracker";
  }

  .panel--sidebar {
    grid-column: auto;
    grid-row: auto;
  }

  .panel--lesson {
    grid-column: auto;
  }

  .panel--practice {
    grid-column: auto;
  }

  .panel--tracker {
    grid-column: auto;
  }
}

@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .panel {
    order: 0;
  }

  .panel--lesson {
    order: 1;
  }

  .panel--practice {
    order: 2;
  }

  .panel--tracker {
    order: 3;
  }
}