/* style.css — Grohl Machine — Dark Industrial Theme */

/* =============================================
   DESIGN TOKENS
   ============================================= */
:root {
  /* Type scale — fluid */
  --text-xs:   clamp(0.65rem,  0.6rem  + 0.25vw, 0.75rem);
  --text-sm:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-base: clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-lg:   clamp(1rem,     0.9rem  + 0.5vw,  1.25rem);
  --text-xl:   clamp(1.25rem,  1rem    + 1vw,    1.75rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-hero: clamp(3rem,     1rem    + 6vw,    7rem);

  /* Spacing — 4px grid */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;

  /* App-specific color palette — dark industrial */
  --color-bg:          #0d0d0d;
  --color-surface:     #161616;
  --color-surface-2:   #1e1e1e;
  --color-surface-3:   #252525;
  --color-surface-raised: #2a2a2a;
  --color-border:      #333333;
  --color-border-dim:  #222222;

  /* Text */
  --color-text:        #e8e0d8;
  --color-text-muted:  #888888;
  --color-text-faint:  #555555;

  /* Accent — amber/orange like tube amp glow */
  --color-amber:       #e8a020;
  --color-amber-bright: #ff9500;
  --color-amber-dim:   #7a4d08;
  --color-amber-glow:  rgba(232, 160, 32, 0.15);
  --color-amber-glow-strong: rgba(232, 160, 32, 0.35);

  /* Record red */
  --color-red:         #e03030;
  --color-red-dim:     #7a1010;
  --color-red-glow:    rgba(224, 48, 48, 0.2);

  /* Sequencer lane colors */
  --color-kick:        #e8a020;    /* amber */
  --color-snare:       #e84820;    /* red-orange */
  --color-hihat:       #d4c030;    /* yellow */
  --color-openhat:     #30c060;    /* green */
  --color-crash:       #20c8d4;    /* cyan */
  --color-tom:         #c030c0;    /* magenta */

  /* Typography */
  --font-display: 'Oswald', 'Bebas Neue', 'Impact', sans-serif;
  --font-mono:    'JetBrains Mono', 'IBM Plex Mono', 'Courier New', monospace;

  /* Transitions */
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-quick:  cubic-bezier(0.4, 0, 0.2, 1);

  /* Pad dimensions */
  --pad-size: clamp(100px, 12vw, 140px);
}

/* =============================================
   GLOBAL LAYOUT
   ============================================= */
body {
  background: var(--color-bg);
  /* Subtle noise texture via repeating gradient */
  background-image:
    radial-gradient(ellipse at 50% 0%, rgba(232,160,32,0.03) 0%, transparent 60%),
    url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  font-family: var(--font-mono);
  color: var(--color-text);
  min-height: 100dvh;
  padding-bottom: var(--space-16);
}

.app-wrapper {
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-6) var(--space-6) var(--space-12);
}

/* =============================================
   HEADER
   ============================================= */
.app-header {
  text-align: center;
  padding: var(--space-8) 0 var(--space-6);
  border-bottom: 1px solid var(--color-border-dim);
  margin-bottom: var(--space-8);
  position: relative;
}

.app-title {
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text);
  line-height: 1;
  /* Subtle amber text glow */
  text-shadow:
    0 0 40px rgba(232, 160, 32, 0.12),
    0 0 80px rgba(232, 160, 32, 0.06);
}

.app-title .grohl {
  color: var(--color-amber);
  text-shadow:
    0 0 20px rgba(232, 160, 32, 0.4),
    0 0 50px rgba(232, 160, 32, 0.15);
}

.app-subtitle {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: var(--space-2);
}

.app-tagline {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-amber);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-top: var(--space-1);
  opacity: 0.85;
}

/* Decorative horizontal rule */
.header-rule {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-5);
}
.header-rule::before,
.header-rule::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--color-amber-dim), transparent);
  opacity: 0.6;
}
.header-rule-text {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.2em;
}

/* =============================================
   MAIN SECTIONS
   ============================================= */
.section-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border-dim);
}

/* =============================================
   DRUM PADS
   ============================================= */
.pads-section {
  margin-bottom: var(--space-8);
}

.pads-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

.drum-pad {
  width: 100%;
  aspect-ratio: 1;
  min-height: 100px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-top-color: #3a3a3a;
  border-left-color: #333;
  border-bottom-color: #111;
  border-right-color: #111;
  border-radius: 3px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition:
    box-shadow 80ms var(--ease-quick),
    transform 80ms var(--ease-quick),
    background-color 80ms var(--ease-quick),
    border-color 80ms var(--ease-quick);
  /* Bevel effect */
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.05),
    inset 0 -1px 0 rgba(0,0,0,0.4),
    0 2px 4px rgba(0,0,0,0.5);
  user-select: none;
  -webkit-user-select: none;
}

/* Subtle inner texture */
.drum-pad::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    160deg,
    rgba(255,255,255,0.025) 0%,
    transparent 40%,
    rgba(0,0,0,0.1) 100%
  );
  pointer-events: none;
}

/* Active/glow state */
.drum-pad.active {
  background: var(--color-surface-3);
  border-color: var(--color-amber-dim);
  border-top-color: var(--color-amber);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.08),
    inset 0 -1px 0 rgba(0,0,0,0.4),
    0 0 0 1px rgba(232, 160, 32, 0.15),
    0 0 16px rgba(232, 160, 32, 0.35),
    0 0 40px rgba(232, 160, 32, 0.15),
    0 4px 12px rgba(0,0,0,0.6);
  transform: scale(0.97) translateY(1px);
}

.drum-pad:hover:not(.active) {
  background: var(--color-surface-3);
  border-top-color: #444;
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.07),
    inset 0 -1px 0 rgba(0,0,0,0.4),
    0 2px 8px rgba(0,0,0,0.5),
    0 0 12px rgba(232, 160, 32, 0.05);
}

.pad-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text);
  line-height: 1;
  transition: color 80ms;
}

.drum-pad.active .pad-name {
  color: var(--color-amber);
}

.pad-key {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  background: var(--color-surface);
  border: 1px solid var(--color-border-dim);
  border-radius: 2px;
  padding: 1px var(--space-2);
  letter-spacing: 0.1em;
  transition: color 80ms, border-color 80ms;
}

.drum-pad.active .pad-key {
  color: var(--color-amber-dim);
  border-color: var(--color-amber-dim);
}

/* LED indicator on each pad */
.pad-led {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-border);
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  transition: background 80ms, box-shadow 80ms;
}

.drum-pad.active .pad-led {
  background: var(--color-amber);
  box-shadow: 0 0 6px var(--color-amber), 0 0 12px rgba(232,160,32,0.4);
}

/* =============================================
   CONTROLS PANEL
   ============================================= */
.controls-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border-dim);
  border-radius: 3px;
  padding: var(--space-6);
  margin-bottom: var(--space-6);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.03),
    0 4px 16px rgba(0,0,0,0.4);
}

/* BPM Row */
.bpm-row {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
}

.bpm-label {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
  min-width: 3rem;
}

.bpm-value {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-amber);
  letter-spacing: 0.05em;
  min-width: 5rem;
  line-height: 1;
  text-shadow: 0 0 20px rgba(232,160,32,0.3);
  font-variant-numeric: tabular-nums lining-nums;
}

.bpm-slider-wrap {
  flex: 1;
  min-width: 160px;
}

input[type="range"].bpm-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--color-border);
  border-radius: 0;
  outline: none;
  cursor: pointer;
  transition: background 200ms;
}

input[type="range"].bpm-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 24px;
  background: var(--color-amber);
  border-radius: 2px;
  cursor: grab;
  box-shadow: 0 0 8px rgba(232,160,32,0.4);
  transition: box-shadow 180ms;
}

input[type="range"].bpm-slider::-webkit-slider-thumb:active {
  cursor: grabbing;
  box-shadow: 0 0 16px rgba(232,160,32,0.7);
}

input[type="range"].bpm-slider::-moz-range-thumb {
  width: 16px;
  height: 24px;
  background: var(--color-amber);
  border-radius: 2px;
  border: none;
  cursor: grab;
  box-shadow: 0 0 8px rgba(232,160,32,0.4);
}

/* Beat indicator dots */
.beat-indicators {
  display: flex;
  gap: var(--space-3);
  align-items: center;
  margin-left: auto;
}

.beat-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-border);
  transition: background 80ms, box-shadow 80ms;
}

.beat-dot.beat-1 {
  width: 12px;
  height: 12px;
}

.beat-dot.active {
  background: var(--color-amber);
  box-shadow: 0 0 8px rgba(232,160,32,0.6), 0 0 16px rgba(232,160,32,0.3);
}

.beat-dot.beat-1.active {
  background: var(--color-amber-bright);
  box-shadow: 0 0 10px rgba(255,149,0,0.8), 0 0 20px rgba(255,149,0,0.3);
}

/* Transport Controls */
.transport-row {
  display: flex;
  gap: var(--space-3);
  align-items: center;
  flex-wrap: wrap;
}

.transport-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-top-color: #333;
  border-bottom-color: #111;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  cursor: pointer;
  transition:
    color 150ms var(--ease-out),
    background 150ms var(--ease-out),
    box-shadow 150ms var(--ease-out),
    border-color 150ms var(--ease-out),
    transform 80ms var(--ease-quick);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.04),
    0 2px 4px rgba(0,0,0,0.4);
  min-height: 44px;
  user-select: none;
  -webkit-user-select: none;
}

.transport-btn svg {
  flex-shrink: 0;
}

.transport-btn:hover {
  color: var(--color-text);
  background: var(--color-surface-3);
  border-color: #3a3a3a;
}

.transport-btn:active {
  transform: translateY(1px);
  box-shadow:
    inset 0 1px 0 rgba(0,0,0,0.2),
    0 1px 2px rgba(0,0,0,0.4);
}

/* Record button */
.transport-btn.btn-record {
  color: var(--color-red);
  border-color: var(--color-red-dim);
}
.transport-btn.btn-record:hover {
  background: rgba(224,48,48,0.08);
  color: #ff5050;
  border-color: #aa2020;
}
.transport-btn.btn-record.recording {
  background: rgba(224,48,48,0.12);
  color: var(--color-red);
  border-color: var(--color-red);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.04),
    0 0 0 1px rgba(224,48,48,0.2),
    0 0 12px rgba(224,48,48,0.25),
    0 2px 4px rgba(0,0,0,0.4);
  animation: rec-pulse 1.2s ease-in-out infinite;
}

@keyframes rec-pulse {
  0%, 100% { box-shadow: inset 0 1px 0 rgba(255,255,255,0.04), 0 0 0 1px rgba(224,48,48,0.2), 0 0 12px rgba(224,48,48,0.25), 0 2px 4px rgba(0,0,0,0.4); }
  50% { box-shadow: inset 0 1px 0 rgba(255,255,255,0.04), 0 0 0 1px rgba(224,48,48,0.5), 0 0 24px rgba(224,48,48,0.5), 0 2px 4px rgba(0,0,0,0.4); }
}

/* Play button */
.transport-btn.btn-play.playing {
  color: var(--color-amber);
  border-color: var(--color-amber-dim);
  background: rgba(232,160,32,0.06);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.04),
    0 0 0 1px rgba(232,160,32,0.15),
    0 0 12px rgba(232,160,32,0.2),
    0 2px 4px rgba(0,0,0,0.4);
}

/* Loop button */
.transport-btn.btn-loop.looping {
  color: var(--color-amber);
  border-color: var(--color-amber-dim);
  background: rgba(232,160,32,0.06);
}

/* Metronome button */
.transport-btn.btn-metro.active {
  color: var(--color-amber);
  border-color: var(--color-amber-dim);
  background: rgba(232,160,32,0.06);
}

/* Stop */
.transport-btn.btn-stop { }

/* Clear */
.transport-btn.btn-clear {
  color: var(--color-text-faint);
}
.transport-btn.btn-clear:hover {
  color: var(--color-text-muted);
}

/* Export */
.transport-btn.btn-export {
  color: var(--color-text-muted);
  margin-left: auto;
}
.transport-btn.btn-export:hover {
  color: var(--color-amber);
  border-color: var(--color-amber-dim);
}

/* Recording status */
.rec-status {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-4);
  background: rgba(224,48,48,0.06);
  border: 1px solid var(--color-red-dim);
  border-radius: 2px;
  opacity: 0;
  transition: opacity 200ms;
  pointer-events: none;
}

.rec-status.visible {
  opacity: 1;
}

.rec-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-red);
  animation: blink 0.8s ease-in-out infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.2; }
}

.rec-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-red);
  letter-spacing: 0.2em;
}

.rec-timer {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-red);
  letter-spacing: 0.1em;
  font-variant-numeric: tabular-nums;
}

/* =============================================
   PROGRESS BAR
   ============================================= */
.progress-section {
  margin-top: var(--space-5);
  display: none;
}

.progress-section.visible {
  display: block;
}

.progress-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-2);
}

.progress-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.progress-time {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
}

.progress-track {
  width: 100%;
  height: 4px;
  background: var(--color-border-dim);
  border-radius: 0;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: var(--color-amber);
  width: 0%;
  transition: width 100ms linear;
  box-shadow: 0 0 8px rgba(232,160,32,0.5);
}

/* =============================================
   SEQUENCER TIMELINE
   ============================================= */
.sequencer-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border-dim);
  border-radius: 3px;
  padding: var(--space-5) var(--space-6);
  margin-bottom: var(--space-6);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.02), 0 4px 16px rgba(0,0,0,0.4);
}

.sequencer-inner {
  position: relative;
  background: var(--color-bg);
  border: 1px solid var(--color-border-dim);
  border-radius: 2px;
  padding: var(--space-4) var(--space-4) var(--space-4) 80px;
  min-height: 160px;
  overflow: hidden;
}

.seq-lanes {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.seq-lane {
  position: relative;
  height: 16px;
  display: flex;
  align-items: center;
}

.seq-lane-label {
  position: absolute;
  left: -76px;
  width: 68px;
  text-align: right;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1;
}

.seq-lane-track {
  flex: 1;
  height: 1px;
  background: var(--color-border-dim);
  position: relative;
}

.seq-hit {
  position: absolute;
  top: -4px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  transform: translateX(-50%);
  transition: opacity 200ms;
}

/* Playhead */
.seq-playhead {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--color-amber);
  left: 80px;
  opacity: 0;
  box-shadow: 0 0 4px var(--color-amber);
  pointer-events: none;
  transition: left 80ms linear;
}

.seq-playhead.visible {
  opacity: 0.8;
}

/* Empty state */
.seq-empty {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.2em;
  pointer-events: none;
}

/* =============================================
   MASTER VOLUME
   ============================================= */
.volume-row {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-5);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border-dim);
}

.volume-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  min-width: 3.5rem;
}

.volume-slider-wrap {
  flex: 1;
  max-width: 200px;
}

input[type="range"].volume-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--color-border);
  border-radius: 0;
  outline: none;
  cursor: pointer;
}

input[type="range"].volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 20px;
  background: var(--color-text-muted);
  border-radius: 2px;
  cursor: grab;
  transition: background 180ms;
}

input[type="range"].volume-slider::-webkit-slider-thumb:hover {
  background: var(--color-text);
}

.vu-meter {
  display: flex;
  gap: 2px;
  align-items: flex-end;
  height: 20px;
}

.vu-bar {
  width: 4px;
  background: var(--color-border);
  border-radius: 0;
  transition: background 80ms, height 80ms;
}

/* =============================================
   KEYBOARD SHORTCUT HINT
   ============================================= */
.keyboard-hint {
  text-align: center;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.12em;
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border-dim);
  border-radius: 2px;
}

.keyboard-hint kbd {
  display: inline-block;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-bottom-color: #111;
  border-radius: 2px;
  padding: 1px 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-amber);
  line-height: 1.4;
  font-variant-numeric: tabular-nums;
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 600px) {
  .app-wrapper {
    padding: var(--space-4) var(--space-4) var(--space-12);
  }

  .pads-grid {
    gap: var(--space-3);
  }

  .pad-name {
    font-size: var(--text-base);
  }

  .transport-row {
    gap: var(--space-2);
  }

  .transport-btn {
    padding: var(--space-3) var(--space-3);
    font-size: 0.65rem;
    gap: var(--space-1);
  }

  .transport-btn .btn-text {
    display: none;
  }

  .bpm-row {
    gap: var(--space-4);
  }

  .beat-indicators {
    margin-left: 0;
  }

  .sequencer-inner {
    padding-left: 60px;
  }

  .seq-lane-label {
    left: -56px;
    width: 50px;
    font-size: 0.6rem;
  }

  .transport-btn.btn-export {
    margin-left: 0;
  }
}

/* =============================================
   FOOTER
   ============================================= */
.app-footer {
  text-align: center;
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border-dim);
  margin-top: var(--space-8);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.15em;
}