/* ========================================
   HeadSet Studio — Premium CSS
   Design: Clean Industrial + Tech Aesthetic
   ======================================== */

:root {
  --color-bg: #0f1117;
  --color-surface: #181b24;
  --color-surface-2: #1e2130;
  --color-border: rgba(255,255,255,0.08);
  --color-border-hover: rgba(255,255,255,0.18);
  --color-accent: #4f8ef7;
  --color-accent-dim: rgba(79,142,247,0.15);
  --color-accent-glow: rgba(79,142,247,0.35);
  --color-green: #22c55e;
  --color-yellow: #f59e0b;
  --color-red: #ef4444;
  --color-text: #e8eaf0;
  --color-text-2: #8b92a5;
  --color-text-3: #545b6e;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --font: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --topbar-h: 60px;
  --transition: 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html { font-size: 15px; }

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 99px; }

/* ========================================
   Browser Warning
   ======================================== */
.browser-warning {
  position: fixed; inset: 0; z-index: 9999;
  background: var(--color-bg);
  display: flex; align-items: center; justify-content: center;
}
.browser-warning.hidden { display: none; }

.browser-warning__inner {
  text-align: center;
  max-width: 420px;
  padding: 48px 40px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
}
.browser-warning__inner svg {
  color: var(--color-yellow);
  margin-bottom: 20px;
}
.browser-warning__inner h2 { font-size: 1.5rem; font-weight: 600; margin-bottom: 12px; }
.browser-warning__inner p { color: var(--color-text-2); line-height: 1.7; margin-bottom: 28px; }
.browser-links { display: flex; gap: 12px; justify-content: center; }

/* ========================================
   Topbar
   ======================================== */
.topbar {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--topbar-h);
  background: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(20px) saturate(160%);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 0;
  padding: 0 28px;
  z-index: 100;
}

.topbar__brand {
  display: flex; align-items: center; gap: 10px;
  margin-right: 32px;
}
.brand-icon {
  width: 36px; height: 36px;
  background: var(--color-accent-dim);
  border: 1px solid var(--color-accent-glow);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  color: var(--color-accent);
}
.brand-name {
  font-size: 1rem; font-weight: 600;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, #e8eaf0 0%, var(--color-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.topbar__nav {
  display: flex; align-items: center; gap: 4px;
  flex: 1;
}

.nav-tab {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem; font-weight: 500;
  font-family: var(--font);
  border: none; cursor: pointer;
  color: var(--color-text-2);
  background: transparent;
  transition: var(--transition);
  letter-spacing: 0.01em;
}
.nav-tab:hover:not(:disabled) {
  color: var(--color-text);
  background: rgba(255,255,255,0.06);
}
.nav-tab.active {
  color: var(--color-accent);
  background: var(--color-accent-dim);
}
.nav-tab:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.topbar__status {
  display: flex; align-items: center; gap: 8px;
  margin-left: auto;
  padding: 6px 14px;
  border-radius: 99px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}
.status-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--color-text-3);
  transition: background 0.4s;
}
.status-dot.connected { background: var(--color-green); box-shadow: 0 0 8px var(--color-green); }
.status-dot.connecting { background: var(--color-yellow); animation: pulse-dot 1s infinite; }
.status-dot.error { background: var(--color-red); }

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.status-text { font-size: 0.82rem; color: var(--color-text-2); font-weight: 500; }

/* ========================================
   Main Content
   ======================================== */
.main-content {
  padding-top: var(--topbar-h);
  min-height: 100vh;
}

.tab-panel {
  display: none;
  padding: 36px 40px;
  animation: fade-in 0.28s ease;
}
.tab-panel.active { display: block; }

@keyframes fade-in {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ========================================
   Connect Page
   ======================================== */
.connect-layout {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 40px;
  max-width: 1100px;
  margin: 40px auto 0;
  align-items: start;
}

.connect-hero {
  display: flex; flex-direction: column; align-items: center;
  text-align: center;
  padding: 56px 40px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
}

.connect-animation {
  position: relative;
  width: 140px; height: 140px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 32px;
}

.ring {
  position: absolute;
  border-radius: 50%;
  border: 1.5px solid var(--color-accent);
  opacity: 0;
  animation: ring-expand 3s infinite;
}
.ring-1 { width: 80px; height: 80px; animation-delay: 0s; }
.ring-2 { width: 110px; height: 110px; animation-delay: 0.8s; }
.ring-3 { width: 140px; height: 140px; animation-delay: 1.6s; }

@keyframes ring-expand {
  0%   { transform: scale(0.6); opacity: 0.7; }
  100% { transform: scale(1);   opacity: 0; }
}

.headphone-icon {
  width: 68px; height: 68px;
  background: linear-gradient(135deg, var(--color-accent-dim), rgba(79,142,247,0.08));
  border: 1.5px solid var(--color-accent-glow);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: var(--color-accent);
  z-index: 1;
}

.connect-title {
  font-size: 1.75rem; font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}
.connect-desc {
  color: var(--color-text-2);
  line-height: 1.7;
  max-width: 360px;
  margin-bottom: 32px;
}
.connect-hint {
  margin-top: 14px;
  font-size: 0.82rem;
  color: var(--color-text-3);
}

.connect-tips {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 32px;
}
.connect-tips h3 {
  font-size: 1rem; font-weight: 600;
  margin-bottom: 20px;
  color: var(--color-text-2);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
}
.tips-list { list-style: none; display: flex; flex-direction: column; gap: 18px; }
.tips-list li { display: flex; align-items: flex-start; gap: 14px; }
.tip-num {
  min-width: 28px; height: 28px;
  background: var(--color-accent-dim);
  border: 1px solid var(--color-accent-glow);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  font-size: 0.8rem; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  margin-top: 1px;
}
.tips-list strong { display: block; font-size: 0.9rem; margin-bottom: 2px; }
.tips-list span { color: var(--color-text-2); font-size: 0.85rem; line-height: 1.5; }

.compat-box {
  display: flex; align-items: center; gap: 8px;
  margin-top: 28px;
  padding: 12px 16px;
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.2);
  border-radius: var(--radius-md);
  font-size: 0.83rem;
  color: var(--color-yellow);
  line-height: 1.5;
}

/* ========================================
   EQ Page
   ======================================== */
.eq-layout {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.eq-presets-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}
.presets-label {
  font-size: 0.8rem; font-weight: 600;
  color: var(--color-text-2);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  white-space: nowrap;
}
.presets-list {
  display: flex; flex-wrap: wrap; gap: 6px;
  flex: 1;
}
.preset-btn {
  padding: 5px 14px;
  border-radius: 99px;
  font-size: 0.83rem; font-weight: 500;
  font-family: var(--font);
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-text-2);
  cursor: pointer;
  transition: var(--transition);
}
.preset-btn:hover { border-color: var(--color-accent); color: var(--color-accent); background: var(--color-accent-dim); }
.preset-btn.active { border-color: var(--color-accent); color: var(--color-accent); background: var(--color-accent-dim); }
.preset-actions { display: flex; gap: 8px; }

/* EQ Main */
.eq-main {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 28px 32px;
}

.eq-canvas-wrap {
  width: 100%; overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  margin-bottom: 32px;
}
#eq-canvas { display: block; width: 100%; height: auto; }

.eq-sliders {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 12px;
  padding: 0 8px;
}

.eq-band {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  flex: 1;
}
.eq-band__db {
  font-size: 0.78rem; font-weight: 600;
  color: var(--color-accent);
  min-height: 18px;
  text-align: center;
  font-variant-numeric: tabular-nums;
}
.eq-band__slider-wrap {
  position: relative;
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.eq-band__slider-wrap::before {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 1px; height: 120px;
  background: var(--color-border);
}
.eq-slider {
  -webkit-appearance: none;
  writing-mode: vertical-lr;
  direction: rtl;
  width: 28px;
  height: 120px;
  background: transparent;
  cursor: pointer;
  outline: none;
  position: relative;
  z-index: 1;
}
.eq-slider::-webkit-slider-runnable-track {
  width: 4px;
  background: var(--color-surface-2);
  border-radius: 99px;
  border: 1px solid var(--color-border-hover);
}
.eq-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid #fff;
  box-shadow: 0 0 10px var(--color-accent-glow);
  cursor: grab;
  transition: transform 0.15s, box-shadow 0.15s;
  margin-left: -7px;
}
.eq-slider::-webkit-slider-thumb:active { transform: scale(1.15); cursor: grabbing; }
.eq-band__freq {
  font-size: 0.72rem; color: var(--color-text-3);
  font-weight: 600;
  letter-spacing: 0.03em;
}

/* EQ Save Row */
.eq-save-row {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.save-preset-form { display: flex; gap: 10px; align-items: center; }
.saved-presets-list { display: flex; flex-wrap: wrap; gap: 8px; }
.saved-preset-chip {
  display: flex; align-items: center; gap: 6px;
  padding: 4px 12px 4px 14px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: 99px;
  font-size: 0.82rem; color: var(--color-text-2);
  cursor: pointer;
  transition: var(--transition);
}
.saved-preset-chip:hover { border-color: var(--color-accent); color: var(--color-text); }
.saved-preset-chip button {
  background: none; border: none; cursor: pointer;
  color: var(--color-text-3);
  font-size: 0.9rem; line-height: 1;
  padding: 0 2px;
  display: flex; align-items: center;
}
.saved-preset-chip button:hover { color: var(--color-red); }

.send-status {
  font-size: 0.85rem;
  color: var(--color-green);
  min-height: 20px;
  text-align: center;
  font-weight: 500;
}

/* ========================================
   Device Info Page
   ======================================== */
.info-layout {
  max-width: 900px; margin: 0 auto;
  display: flex; flex-direction: column; gap: 24px;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.info-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 22px 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.info-card:hover { border-color: var(--color-border-hover); box-shadow: 0 4px 24px rgba(0,0,0,0.2); }

.info-card__icon {
  width: 42px; height: 42px;
  background: var(--color-accent-dim);
  border: 1px solid var(--color-accent-glow);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  color: var(--color-accent);
}

.info-card__body { display: flex; flex-direction: column; gap: 4px; }
.info-label { font-size: 0.78rem; color: var(--color-text-3); font-weight: 500; text-transform: uppercase; letter-spacing: 0.06em; }
.info-value { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; }

.battery-bar-wrap {
  height: 4px;
  background: var(--color-surface-2);
  border-radius: 99px;
  overflow: hidden;
  border: 1px solid var(--color-border);
}
.battery-bar {
  height: 100%;
  border-radius: 99px;
  background: var(--color-green);
  transition: width 0.6s cubic-bezier(0.16,1,0.3,1);
}

.info-actions { display: flex; gap: 12px; }

/* Log Panel */
.log-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.log-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 12px 18px;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.8rem; font-weight: 600;
  color: var(--color-text-2);
  text-transform: uppercase; letter-spacing: 0.07em;
}
.log-body {
  height: 200px;
  overflow-y: auto;
  padding: 10px 18px;
  font-size: 0.78rem;
  font-family: 'SF Mono', 'Fira Code', monospace;
  color: var(--color-text-2);
  line-height: 1.8;
}
.log-entry { display: flex; gap: 10px; }
.log-time { color: var(--color-text-3); min-width: 70px; }
.log-msg.ok   { color: var(--color-green); }
.log-msg.err  { color: var(--color-red); }
.log-msg.info { color: var(--color-accent); }
.log-msg.warn { color: var(--color-yellow); }

/* ========================================
   Buttons
   ======================================== */
.btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 9px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem; font-weight: 600;
  font-family: var(--font);
  border: none; cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  letter-spacing: 0.01em;
  text-decoration: none;
}
.btn:active { transform: scale(0.97); }

.btn--primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 0 0 0 var(--color-accent-glow);
}
.btn--primary:hover { background: #6ba0ff; box-shadow: 0 4px 18px var(--color-accent-glow); }

.btn--outline {
  background: transparent;
  color: var(--color-text-2);
  border: 1px solid var(--color-border);
}
.btn--outline:hover { border-color: var(--color-accent); color: var(--color-accent); background: var(--color-accent-dim); }

.btn--danger-outline {
  background: transparent;
  color: #ef4444;
  border: 1px solid rgba(239,68,68,0.3);
}
.btn--danger-outline:hover { background: rgba(239,68,68,0.1); border-color: #ef4444; }

.btn--ghost {
  background: transparent; color: var(--color-text-3); border: none;
}
.btn--ghost:hover { color: var(--color-text); }

.btn--large { padding: 13px 32px; font-size: 0.95rem; border-radius: var(--radius-md); }
.btn--sm { padding: 6px 14px; font-size: 0.8rem; }
.btn--xs { padding: 3px 10px; font-size: 0.75rem; }

/* ========================================
   Text Input
   ======================================== */
.text-input {
  padding: 8px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-2);
  color: var(--color-text);
  font-size: 0.88rem;
  font-family: var(--font);
  outline: none;
  transition: border-color var(--transition);
  min-width: 200px;
}
.text-input:focus { border-color: var(--color-accent); box-shadow: 0 0 0 2px var(--color-accent-dim); }
.text-input::placeholder { color: var(--color-text-3); }

/* ========================================
   Modal
   ======================================== */
.modal-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
}
.modal-overlay.hidden { display: none; }

.modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 40px 36px;
  text-align: center;
  max-width: 360px;
  width: 90%;
  animation: modal-in 0.28s cubic-bezier(0.16,1,0.3,1);
}
@keyframes modal-in {
  from { opacity:0; transform: scale(0.9) translateY(20px); }
  to   { opacity:1; transform: scale(1) translateY(0); }
}

.modal__icon { margin: 0 auto 20px; }
.modal__icon--warn { color: var(--color-yellow); }
.modal h3 { font-size: 1.2rem; font-weight: 600; margin-bottom: 10px; }
.modal p { color: var(--color-text-2); font-size: 0.88rem; line-height: 1.6; margin-bottom: 24px; }

/* ========================================
   Toast
   ======================================== */
.toast-container {
  position: fixed;
  bottom: 28px; right: 28px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}
.toast {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 18px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.86rem;
  color: var(--color-text);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  pointer-events: auto;
  animation: toast-in 0.3s cubic-bezier(0.16,1,0.3,1);
  max-width: 320px;
}
.toast.success { border-left: 3px solid var(--color-green); }
.toast.error   { border-left: 3px solid var(--color-red); }
.toast.info    { border-left: 3px solid var(--color-accent); }
.toast.warning { border-left: 3px solid var(--color-yellow); }

@keyframes toast-in {
  from { opacity:0; transform: translateX(30px); }
  to   { opacity:1; transform: translateX(0); }
}
@keyframes toast-out {
  from { opacity:1; transform: translateX(0); max-height: 80px; margin-bottom: 0; }
  to   { opacity:0; transform: translateX(30px); max-height: 0; margin-bottom: -10px; }
}
.toast.removing { animation: toast-out 0.3s ease forwards; }