/* ===== CSS VARIABLES ===== */
:root {
  --bg: #f0f4f8;
  --bg2: #ffffff;
  --bg3: #e8eef5;
  --text: #1a2332;
  --text2: #4a5568;
  --text3: #718096;
  --accent-green: #48bb78;
  --accent-green-light: #c6f6d5;
  --accent-blue: #4299e1;
  --accent-blue-light: #bee3f8;
  --accent-orange: #ed8936;
  --accent-red: #fc8181;
  --border: #d1dce8;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
  --radius: 14px;
  --radius-sm: 8px;
  --header-h: 64px;
  --footer-h: 48px;
  --transition: 0.25s ease;
  --crown: #f6c90e;
}

[data-theme="dark"] {
  --bg: #0f1923;
  --bg2: #1a2840;
  --bg3: #243550;
  --text: #e8f0fe;
  --text2: #a0b4cc;
  --text3: #6b8aaa;
  --border: #2d4060;
  --shadow: 0 2px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.4);
  --accent-green-light: #1a3a2a;
  --accent-blue-light: #1a2e42;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Quicksand', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background var(--transition), color var(--transition);
  padding-top: var(--header-h);
  padding-bottom: var(--footer-h);
}

/* ===== HEADER ===== */
.app-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  z-index: 100;
  transition: background var(--transition);
}
.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
}
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { font-size: 1.6rem; }
.logo-text {
  font-family: 'Nunito', sans-serif;
  font-weight: 900;
  font-size: 1.2rem;
  color: var(--text);
  letter-spacing: -0.3px;
}
.theme-toggle {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 40px; height: 40px;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
}
.theme-toggle:hover { transform: rotate(20deg) scale(1.1); }

/* ===== FOOTER ===== */
.app-footer {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  height: var(--footer-h);
  background: var(--bg2);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: var(--text3);
  transition: background var(--transition);
}
.app-footer strong { color: var(--accent-blue); }

/* ===== PAGES ===== */
.page { display: none; flex: 1; }
.page.active { display: block; }

/* ===== LANDING ===== */
.landing-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 60px 24px 40px;
}
.landing-hero { text-align: center; margin-bottom: 50px; }
.landing-title {
  font-family: 'Nunito', sans-serif;
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 14px;
}
.accent { color: var(--accent-green); }
.landing-sub { color: var(--text2); font-size: 1.1rem; }

.mode-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}
.mode-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: var(--shadow);
}
.mode-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent-blue);
}
.mode-card-icon { font-size: 2.8rem; margin-bottom: 16px; }
.mode-card h2 {
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1.4rem;
  margin-bottom: 10px;
}
.mode-card p { color: var(--text2); font-size: 0.95rem; margin-bottom: 24px; line-height: 1.5; }

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 22px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: 'Quicksand', sans-serif;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--accent-green); color: white; }
.btn-primary:hover { background: #38a169; box-shadow: 0 4px 12px rgba(72,187,120,0.4); }
.btn-secondary { background: var(--accent-blue); color: white; }
.btn-secondary:hover { background: #3182ce; box-shadow: 0 4px 12px rgba(66,153,225,0.4); }
.btn-outline {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text2);
}
.btn-outline:hover { border-color: var(--accent-blue); color: var(--accent-blue); }
.btn-green { background: var(--accent-green-light); color: #276749; border: 1px solid var(--accent-green); }
.btn-green:hover { background: var(--accent-green); color: white; }
.btn-blue { background: var(--accent-blue-light); color: #1a4a7a; border: 1px solid var(--accent-blue); }
.btn-blue:hover { background: var(--accent-blue); color: white; }
.btn-danger { background: #fff5f5; color: #c53030; border: 1px solid #fc8181; }
.btn-danger:hover { background: #fc8181; color: white; }
.btn-sm { padding: 7px 14px; font-size: 0.85rem; }
.btn-spin {
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  font-size: 1.1rem;
  padding: 14px 36px;
  border-radius: 50px;
  box-shadow: 0 4px 20px rgba(102,126,234,0.4);
  margin: 12px auto;
  display: block;
}
.btn-spin:hover { transform: scale(1.05); box-shadow: 0 6px 28px rgba(102,126,234,0.6); }
.btn-spin:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }

/* ===== PAGE CONTAINER ===== */
.page-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 28px 24px 40px;
}
.page-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}
.back-btn {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 8px 16px;
  cursor: pointer;
  font-family: 'Quicksand', sans-serif;
  font-weight: 600;
  color: var(--text2);
  transition: all var(--transition);
}
.back-btn:hover { color: var(--accent-blue); border-color: var(--accent-blue); }
.page-title {
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1.5rem;
}

/* ===== INPUT CARD ===== */
.input-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
  transition: background var(--transition);
}
.input-label {
  display: block;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 10px;
  color: var(--text);
}
.hint { font-weight: 500; color: var(--text3); font-size: 0.85rem; }

.student-textarea {
  width: 100%;
  min-height: 140px;
  padding: 12px 14px;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'Quicksand', sans-serif;
  font-size: 0.9rem;
  color: var(--text);
  resize: vertical;
  transition: border-color var(--transition);
  line-height: 1.6;
}
.student-textarea:focus { outline: none; border-color: var(--accent-blue); }

.input-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 10px;
  margin-bottom: 8px;
}
.count-badge {
  background: var(--accent-blue-light);
  color: var(--accent-blue);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 700;
}

.sorted-list {
  background: var(--bg3);
  border-radius: var(--radius-sm);
  max-height: 180px;
  overflow-y: auto;
  font-size: 0.85rem;
  color: var(--text2);
  line-height: 1.7;
  padding: 0;
}
.sorted-list:not(:empty) { padding: 10px 14px; border: 1px solid var(--border); margin-top: 8px; }
.sorted-list-item { display: flex; align-items: center; gap: 8px; }
.sorted-list-item .sid { color: var(--text3); font-size: 0.8rem; min-width: 36px; }

.group-count-row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}
.number-input {
  width: 100px;
  padding: 10px 14px;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'Quicksand', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  transition: border-color var(--transition);
}
.number-input:focus { outline: none; border-color: var(--accent-blue); }

.error-msg {
  color: #c53030;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 6px;
  min-height: 18px;
  transition: all var(--transition);
}

/* ===== RESULTS ===== */
.results-section { margin-top: 10px; }
.results-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  box-shadow: var(--shadow);
}
.results-title {
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1.2rem;
}
.toolbar-btns { display: flex; gap: 8px; flex-wrap: wrap; }

.groups-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}

.group-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition);
  animation: cardIn 0.35s ease forwards;
  opacity: 0;
}
@keyframes cardIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
.group-card:hover { box-shadow: var(--shadow-lg); }

.group-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1.5px solid var(--border);
}
.group-card-title {
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1rem;
}
.group-badge-count {
  background: var(--accent-green-light);
  color: #276749;
  padding: 2px 9px;
  border-radius: 12px;
  font-size: 0.8rem;
  font-weight: 700;
}

.student-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px 0;
  font-size: 0.88rem;
  border-bottom: 1px solid var(--bg3);
  transition: background var(--transition);
}
.student-row:last-of-type { border-bottom: none; }
.student-row .sid { color: var(--text3); font-size: 0.78rem; min-width: 32px; }
.student-row .sname { flex: 1; font-weight: 600; }
.crown-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  opacity: 0.35;
  transition: all var(--transition);
  padding: 2px 4px;
  border-radius: 4px;
}
.crown-btn:hover { opacity: 0.7; transform: scale(1.2); }
.crown-btn.active { opacity: 1; }
.student-row.is-leader {
  background: linear-gradient(90deg, rgba(246,201,14,0.1), transparent);
  border-radius: 6px;
}
.student-row.is-leader .sname { color: #b7791f; }

.topic-input {
  width: 100%;
  margin-top: 12px;
  padding: 7px 10px;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'Quicksand', sans-serif;
  font-size: 0.85rem;
  color: var(--text);
  transition: border-color var(--transition);
}
.topic-input:focus { outline: none; border-color: var(--accent-blue); }

/* ===== SPIN STEPS ===== */
.spin-step { }
.step-header { text-align: center; margin-bottom: 24px; }
.step-header h3 { font-family: 'Nunito', sans-serif; font-weight: 800; font-size: 1.3rem; margin-bottom: 6px; }
.step-sub { color: var(--text2); font-size: 0.95rem; }

/* Leader Groups */
.leader-groups {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 14px;
  margin-bottom: 20px;
}
.leader-group-card {
  background: var(--bg2);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  box-shadow: var(--shadow);
}
.leader-group-title {
  font-weight: 800;
  font-size: 0.9rem;
  margin-bottom: 10px;
  color: var(--text2);
  display: flex;
  align-items: center;
  gap: 6px;
}
.leader-select {
  width: 100%;
  padding: 8px 10px;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'Quicksand', sans-serif;
  font-size: 0.88rem;
  color: var(--text);
  cursor: pointer;
  transition: border-color var(--transition);
}
.leader-select:focus { outline: none; border-color: var(--accent-blue); }
.leader-selected-name {
  margin-top: 8px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--crown);
  min-height: 18px;
}

/* ===== SPIN WHEEL ===== */
.spin-layout {
  display: grid;
  grid-template-columns: 400px 1fr;
  gap: 28px;
  align-items: start;
}
@media (max-width: 800px) {
  .spin-layout { grid-template-columns: 1fr; }
}

.wheel-panel {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  text-align: center;
  position: sticky;
  top: calc(var(--header-h) + 16px);
}

.wheel-wrapper {
  position: relative;
  display: inline-block;
  margin-bottom: 16px;
}
.wheel-pointer {
  position: absolute;
  top: -16px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 1.8rem;
  color: #e53e3e;
  z-index: 10;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.3));
  line-height: 1;
}

#spinWheel {
  border-radius: 50%;
  display: block;
  box-shadow: 0 6px 30px rgba(0,0,0,0.2);
}

.spin-result {
  background: linear-gradient(135deg, var(--accent-green-light), var(--accent-blue-light));
  border: 2px solid var(--accent-green);
  border-radius: var(--radius);
  padding: 14px 20px;
  margin: 12px 0;
  animation: popIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
@keyframes popIn {
  from { opacity:0; transform: scale(0.8); }
  to   { opacity:1; transform: scale(1); }
}
.spin-result-label { font-size: 0.8rem; font-weight: 600; color: var(--text3); text-transform: uppercase; letter-spacing: 1px; }
.spin-result-name { font-family: 'Nunito', sans-serif; font-weight: 900; font-size: 1.2rem; color: var(--text); }
.spin-result-group { font-size: 0.85rem; color: var(--accent-blue); font-weight: 700; margin-top: 2px; }

/* Spin Mode Toggle */
.spin-mode-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin: 12px 0;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text2);
}
.toggle-label { min-width: 70px; }
.toggle-label:first-child { text-align: right; }
.toggle-switch { position: relative; display: inline-block; width: 44px; height: 24px; }
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.toggle-slider {
  position: absolute; cursor: pointer;
  top:0; left:0; right:0; bottom:0;
  background: var(--accent-blue);
  border-radius: 24px;
  transition: .3s;
}
.toggle-slider:before {
  position: absolute; content: "";
  height: 18px; width: 18px;
  left: 3px; bottom: 3px;
  background: white;
  border-radius: 50%;
  transition: .3s;
}
input:checked + .toggle-slider { background: var(--accent-orange); }
input:checked + .toggle-slider:before { transform: translateX(20px); }

.spin-status {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 10px;
}
.status-badge {
  background: var(--bg3);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 700;
}
.group-badge { background: var(--accent-blue-light); border-color: var(--accent-blue); color: var(--accent-blue); }

/* Spin Groups Live */
.spin-groups-panel {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
.panel-title {
  font-family: 'Nunito', sans-serif;
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1.5px solid var(--border);
}
.spin-groups-live { display: flex; flex-direction: column; gap: 12px; }

.spin-live-card {
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  transition: all var(--transition);
}
.spin-live-card.active-group {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(66,153,225,0.15);
}
.spin-live-card-title {
  font-weight: 800;
  font-size: 0.88rem;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.spin-live-members { display: flex; flex-direction: column; gap: 3px; margin-top: 2px; }
.member-chip {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 0.8rem;
  font-weight: 500;
  animation: chipIn 0.3s ease;
  display: flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.member-chip strong { color: var(--accent-blue); font-weight: 700; }
@keyframes chipIn {
  from { opacity:0; transform:translateX(-8px); }
  to   { opacity:1; transform:translateX(0); }
}
.member-chip.leader { background: rgba(246,201,14,0.12); border-color: var(--crown); }
.member-chip.leader strong { color: #b7791f; }

/* ===== UTILITY ===== */
.hidden { display: none !important; }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg3); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .landing-container { padding: 30px 16px; }
  .page-container { padding: 18px 16px 40px; }
  .results-toolbar { flex-direction: column; }
  .toolbar-btns { justify-content: flex-start; }
  .header-inner { padding: 0 16px; }
  .logo-text { font-size: 1rem; }
}