/* ============ English Flow — Design Moderno ============ */
:root {
  --bg-0: #070b18;
  --bg-1: #0d1326;
  --surface: rgba(255, 255, 255, 0.06);
  --surface-2: rgba(255, 255, 255, 0.09);
  --border: rgba(255, 255, 255, 0.12);
  --text: #eef2ff;
  --muted: #9aa6c4;
  --accent: #7c5cff;
  --accent-2: #2dd4ff;
  --ok: #34d399;
  --err: #fb7185;
  --warn: #fbbf24;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.6);
  --grad: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 12% -10%, rgba(124, 92, 255, 0.25), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(45, 212, 255, 0.18), transparent 55%),
    radial-gradient(700px 700px at 50% 120%, rgba(124, 92, 255, 0.15), transparent 60%),
    linear-gradient(180deg, var(--bg-1), var(--bg-0));
  background-attachment: fixed;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Layout ---------- */
.app {
  max-width: 960px;
  margin: 0 auto;
  padding: 28px clamp(16px, 4vw, 32px) 56px;
}

/* ---------- Header ---------- */
.topbar {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 22px clamp(18px, 3vw, 28px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--shadow);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.brand .logo {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: var(--grad);
  box-shadow: 0 8px 24px -6px rgba(124, 92, 255, 0.6);
  font-size: 22px;
  flex-shrink: 0;
}

.brand h1 {
  margin: 0;
  font-size: clamp(1.4rem, 3.5vw, 1.9rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.brand .tag {
  margin-left: auto;
  font-size: 0.78rem;
  color: var(--muted);
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  white-space: nowrap;
}

/* ---------- Controls ---------- */
.controls {
  display: flex;
  gap: 14px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.controls label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  flex: 1 1 130px;
}

.field {
  position: relative;
}

select, input, textarea {
  width: 100%;
  background: rgba(7, 11, 24, 0.6);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 11px 12px;
  font-size: 0.92rem;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
  appearance: none;
}

select {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%239aa6c4' stroke-width='2.5'><path d='M6 9l6 6 6-6'/></svg>");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 34px;
  cursor: pointer;
}

select:focus, input:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.25);
  background: rgba(7, 11, 24, 0.85);
}

textarea { resize: vertical; line-height: 1.6; }

.status {
  margin-left: auto;
  font-size: 1.4rem;
  line-height: 1;
  align-self: center;
  flex: 0 0 auto;
  filter: drop-shadow(0 0 8px currentColor);
}

/* ---------- Tabs (segmented) ---------- */
nav.tabs {
  display: flex;
  gap: 6px;
  padding: 6px;
  background: rgba(7, 11, 24, 0.5);
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow-x: auto;
  scrollbar-width: none;
}
nav.tabs::-webkit-scrollbar { display: none; }

.tab {
  flex: 1 1 auto;
  white-space: nowrap;
  background: transparent;
  color: var(--muted);
  border: none;
  padding: 10px 16px;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  font-family: inherit;
  transition: color 0.2s, background 0.3s, transform 0.1s;
}
.tab:hover { color: var(--text); }
.tab:active { transform: scale(0.97); }
.tab.active {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 8px 22px -8px rgba(45, 212, 255, 0.6);
}

/* ---------- Panels ---------- */
main { margin-top: 24px; }

.panel { display: none; }
.panel.active {
  display: block;
  animation: fadeUp 0.4s ease both;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--shadow);
  padding: clamp(18px, 3vw, 26px);
}

.panel h2 {
  margin: 0 0 4px;
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.panel .subtitle {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.9rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--grad);
  color: #fff;
  border: none;
  padding: 11px 18px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: 700;
  font-size: 0.9rem;
  font-family: inherit;
  transition: transform 0.12s, box-shadow 0.2s, opacity 0.2s;
  box-shadow: 0 10px 24px -10px rgba(124, 92, 255, 0.7);
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 14px 30px -10px rgba(45, 212, 255, 0.7); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; box-shadow: none; }

.btn.playing {
  animation: pulse 1s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 10px 24px -10px rgba(124, 92, 255, 0.7); }
  50% { box-shadow: 0 0 0 4px rgba(45, 212, 255, 0.35), 0 10px 24px -10px rgba(45, 212, 255, 0.7); }
}

.btn.ghost {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  box-shadow: none;
}
.btn.ghost:hover { background: rgba(255, 255, 255, 0.14); }

.btn-group {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin: 14px 0;
}

/* ---------- Sentence / text blocks ---------- */
.sentence {
  background: rgba(7, 11, 24, 0.55);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent-2);
  padding: 16px 18px;
  margin: 14px 0;
  border-radius: var(--radius-sm);
  font-size: 1.15rem;
  line-height: 1.6;
  letter-spacing: 0.01em;
}

.glossary {
  color: var(--muted);
  font-size: 0.86rem;
  margin-bottom: 14px;
  padding: 12px 14px;
  background: rgba(45, 212, 255, 0.07);
  border: 1px dashed rgba(45, 212, 255, 0.3);
  border-radius: var(--radius-sm);
}

.grammar-topic {
  margin: 16px 0 6px;
  font-size: 1.2rem;
  color: var(--accent-2);
}

.grammar-structure {
  display: inline-block;
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.86rem;
  color: var(--accent);
  background: rgba(45, 212, 255, 0.1);
  border: 1px solid rgba(45, 212, 255, 0.3);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.grammar-explanation {
  background: rgba(56, 189, 248, 0.07);
  border-left: 3px solid var(--accent-2);
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  line-height: 1.6;
  margin-bottom: 14px;
}

.grammar-examples {
  list-style: none;
  padding: 0;
  margin: 0 0 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.grammar-examples li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: rgba(7, 11, 24, 0.45);
  border: 1px solid var(--border);
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
}

.grammar-examples li span { flex: 1; }

.grammar-play {
  flex: 0 0 auto;
  padding: 6px 10px;
  font-size: 0.9rem;
}

.memhack-card {
  margin-top: 8px;
}

.memhack-progress {
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.memhack-phrase {
  font-size: 1.25rem;
  line-height: 1.5;
  padding: 16px 18px;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
}

.memhack-pt {
  font-size: 1rem;
  color: var(--accent-2);
  margin: -6px 0 14px;
  padding-left: 4px;
}

.memhack-rating {
  margin-top: 4px;
}

.memhack-easy { border-color: rgba(52, 211, 153, 0.5); }
.memhack-medium { border-color: rgba(250, 204, 21, 0.5); }
.memhack-hard { border-color: rgba(251, 113, 133, 0.5); }

.memhack-easy:hover { background: rgba(52, 211, 153, 0.15); }
.memhack-medium:hover { background: rgba(250, 204, 21, 0.15); }
.memhack-hard:hover { background: rgba(251, 113, 133, 0.15); }

.hint {
  color: var(--muted);
  font-size: 0.92rem;
  margin: 0 0 14px;
}
.hint em { color: var(--accent-2); font-style: italic; }

.result {
  background: rgba(7, 11, 24, 0.55);
  border: 1px solid var(--border);
  padding: 16px 18px;
  margin: 14px 0;
  border-radius: var(--radius-sm);
  white-space: pre-wrap;
  font-size: 0.94rem;
  animation: fadeUp 0.3s ease both;
}
.result.ok { border-color: rgba(52, 211, 153, 0.5); }
.result.err { border-color: rgba(251, 113, 133, 0.5); }

label.field-label {
  display: block;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 16px 0 6px;
}

/* ---------- Chat ---------- */
.chat {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
  max-height: 50vh;
  min-height: 120px;
  overflow-y: auto;
  padding: 4px;
  scrollbar-width: thin;
}
.msg {
  padding: 12px 15px;
  border-radius: 16px;
  max-width: 82%;
  font-size: 0.94rem;
  line-height: 1.5;
  word-wrap: break-word;
  animation: fadeUp 0.3s ease both;
}
.msg.ai {
  background: linear-gradient(135deg, rgba(124, 92, 255, 0.22), rgba(45, 212, 255, 0.18));
  border: 1px solid rgba(124, 92, 255, 0.35);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}
.msg.user {
  background: linear-gradient(135deg, rgba(52, 211, 153, 0.22), rgba(45, 212, 255, 0.16));
  border: 1px solid rgba(52, 211, 153, 0.35);
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}

.converse-header {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.converse-header h2 { margin: 0; }
.converse-persona-label { margin: 0; }
.converse-persona-label .field { display: inline-block; }
.converse-persona-label select { min-width: 140px; }

.converse-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}
.converse-controls input { flex: 1 1 200px; }

.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 22px 0;
}

.footer {
  margin-top: 36px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
}

.hidden { display: none; }

/* ---------- Login ---------- */
.login-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background:
    radial-gradient(1000px 600px at 20% 0%, rgba(124, 92, 255, 0.25), transparent 60%),
    radial-gradient(900px 500px at 100% 100%, rgba(45, 212, 255, 0.18), transparent 55%),
    linear-gradient(180deg, var(--bg-1), var(--bg-0));
  backdrop-filter: blur(8px);
}
.login-wrap {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  min-height: 100vh;
  background:
    radial-gradient(1000px 600px at 20% 0%, rgba(124, 92, 255, 0.25), transparent 60%),
    radial-gradient(900px 500px at 100% 100%, rgba(45, 212, 255, 0.18), transparent 55%),
    linear-gradient(180deg, var(--bg-1), var(--bg-0));
}
.login-card {
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}
.login-card .logo {
  align-self: center;
  display: grid;
  place-items: center;
  width: 54px;
  height: 54px;
  border-radius: 16px;
  background: var(--grad);
  box-shadow: 0 8px 24px -6px rgba(124, 92, 255, 0.6);
  font-size: 26px;
  margin-bottom: 4px;
}
.login-card h1 {
  margin: 0;
  text-align: center;
  font-size: 1.4rem;
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.login-card .subtitle {
  margin: 0 0 8px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}
.login-card .btn { justify-content: center; width: 100%; }
.login-error { color: var(--err); font-size: 0.85rem; min-height: 1.1em; text-align: center; }

.users-list { list-style: none; padding: 0; margin: 6px 0 12px; color: var(--text); font-size: 0.9rem; }
.users-list li { padding: 6px 10px; background: rgba(7, 11, 24, 0.5); border: 1px solid var(--border); border-radius: 8px; margin-bottom: 6px; }

/* ---------- Responsivo ---------- */
@media (max-width: 640px) {
  .brand .tag { margin-left: 0; width: 100%; text-align: center; }
  .status { margin-left: 0; }
  .controls label { flex: 1 1 100%; }
  .btn { flex: 1 1 auto; justify-content: center; }
  nav.tabs { border-radius: var(--radius-sm); }
  .sentence { font-size: 1.05rem; }
}

@media (min-width: 641px) and (max-width: 900px) {
  .controls label { flex: 1 1 45%; }
}