/* ==========================================================================
   CSS Design Tokens & Core Setup
   ========================================================================== */
:root {
  /* Color Palette (Premium Neon Dark Sport Style) */
  --bg-main: #0a0c10;
  --bg-card: rgba(22, 28, 45, 0.45);
  --bg-card-hover: rgba(22, 28, 45, 0.65);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: var(--accent-orange);
  
  /* Text Colors */
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  
  /* Brand Accent Neon Colors */
  --accent-orange: #ff6b00;
  --accent-orange-glow: rgba(255, 107, 0, 0.4);
  --accent-red: #ff2a5f;
  --accent-red-glow: rgba(255, 42, 95, 0.45);
  --accent-green: #00e676;
  --accent-green-glow: rgba(0, 230, 118, 0.4);
  --accent-blue: #00b0ff;
  --accent-blue-glow: rgba(0, 176, 255, 0.4);
  
  /* Typography */
  --font-display: 'Kanit', sans-serif;
  --font-numeric: 'Orbitron', sans-serif;
  --font-body: 'Noto Sans KR', sans-serif;
  
  /* Transitions & Layout */
  --transition-speed: 0.3s;
  --border-radius-lg: 16px;
  --border-radius-md: 10px;
  --border-radius-sm: 6px;
  --max-width: 1200px;
}

/* ==========================================================================
   Global Reset & Base Styles
   ========================================================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-body);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(255, 42, 95, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(255, 107, 0, 0.05) 0%, transparent 40%);
}

.app-container {
  width: 100%;
  max-width: var(--max-width);
  padding: 24px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ==========================================================================
   Header & Footer
   ========================================================================== */
.app-header {
  text-align: center;
  margin-bottom: 24px;
}

.logo-text {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 3rem;
  letter-spacing: 2px;
  line-height: 1.1;
  text-shadow: 0 0 15px rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
}

.logo-text .accent {
  color: var(--accent-orange);
  text-shadow: 0 0 20px var(--accent-orange-glow);
  position: relative;
}

.subtitle {
  font-size: 0.95rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 3px;
  margin-top: 8px;
}

.app-footer {
  text-align: center;
  padding: 32px 0 16px;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
}

/* ==========================================================================
   Layout Main Grid
   ========================================================================== */
.app-main {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 24px;
  align-items: start;
}

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

/* ==========================================================================
   Components: Cards & Badges
   ========================================================================== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 28px;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  transition: border-color var(--transition-speed), transform var(--transition-speed);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.12);
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

/* Status Badge */
.state-badge {
  padding: 6px 14px;
  border-radius: 50px;
  font-weight: 900;
  font-size: 0.8rem;
  font-family: var(--font-display);
  letter-spacing: 1.5px;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
  transition: all var(--transition-speed) ease;
  box-shadow: 0 0 10px transparent;
}

.state-badge.waiting {
  background-color: var(--accent-blue);
  box-shadow: 0 0 12px var(--accent-blue-glow);
  color: #fff;
}

.state-badge.work {
  background-color: var(--accent-red);
  box-shadow: 0 0 15px var(--accent-red-glow);
  color: #fff;
  animation: pulse-red 2s infinite;
}

.state-badge.rest {
  background-color: var(--accent-green);
  box-shadow: 0 0 15px var(--accent-green-glow);
  color: #052e16;
}

@keyframes pulse-red {
  0% { transform: scale(1); box-shadow: 0 0 12px var(--accent-red-glow); }
  50% { transform: scale(1.05); box-shadow: 0 0 20px var(--accent-red-glow); }
  100% { transform: scale(1); box-shadow: 0 0 12px var(--accent-red-glow); }
}

/* ==========================================================================
   Display Section (Workout Panel)
   ========================================================================== */
.display-section {
  display: flex;
  flex-direction: column;
  gap: 24px;
  background: linear-gradient(135deg, rgba(22, 28, 45, 0.6) 0%, rgba(10, 12, 16, 0.8) 100%);
  border-color: rgba(255, 107, 0, 0.15);
  position: sticky;
  top: 24px;
}

.status-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 16px;
}

.round-counter {
  display: flex;
  align-items: baseline;
  font-family: var(--font-numeric);
}

.round-counter .label {
  font-size: 0.75rem;
  font-family: var(--font-display);
  color: var(--text-secondary);
  margin-right: 8px;
  font-weight: 700;
  letter-spacing: 1px;
}

.round-counter .value {
  font-size: 1.8rem;
  font-weight: 900;
  color: #fff;
}

.round-counter .divider {
  font-size: 1.2rem;
  color: var(--text-muted);
  margin: 0 6px;
}

/* Timer Display */
.timer-container {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 16px 0;
}

.timer-text {
  font-family: var(--font-numeric);
  font-size: 5rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -2px;
  text-shadow: 0 0 20px rgba(255, 255, 255, 0.1);
  line-height: 1;
}

.timer-text.rest-time {
  color: var(--accent-green);
  text-shadow: 0 0 25px var(--accent-green-glow);
}

.timer-text.work-time {
  color: var(--accent-red);
  text-shadow: 0 0 25px var(--accent-red-glow);
}

/* Combo Card Screen */
.combo-container {
  background: rgba(10, 12, 16, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-md);
  padding: 32px 20px;
  text-align: center;
  min-height: 180px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
}

.combo-container.flash-active {
  animation: border-flash 0.3s ease-out;
}

@keyframes border-flash {
  0% { border-color: var(--accent-orange); box-shadow: inset 0 0 20px rgba(255, 107, 0, 0.3); }
  100% { border-color: rgba(255, 255, 255, 0.05); box-shadow: inset 0 0 0 transparent; }
}

.combo-title {
  font-size: 0.75rem;
  font-family: var(--font-display);
  letter-spacing: 3px;
  color: var(--text-muted);
  margin-bottom: 12px;
  font-weight: 700;
}

.combo-text {
  font-family: var(--font-display);
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--accent-orange);
  text-shadow: 0 0 25px var(--accent-orange-glow);
  word-wrap: break-word;
  max-width: 100%;
  line-height: 1.3;
  transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.combo-text.combo-rest {
  color: var(--accent-green);
  text-shadow: 0 0 25px var(--accent-green-glow);
}

.combo-text.scale-pop {
  transform: scale(1.1);
}

/* Control Buttons */
.controls-container {
  display: flex;
  gap: 12px;
  margin-top: 10px;
}

.btn {
  font-family: var(--font-display);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border: none;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: all var(--transition-speed) cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  justify-content: center;
  align-items: center;
  outline: none;
}

.btn-lg {
  padding: 18px 24px;
  font-size: 1.1rem;
  flex: 1;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-orange) 0%, #e65c00 100%);
  color: #fff;
  box-shadow: 0 4px 15px var(--accent-orange-glow);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 107, 0, 0.6);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-danger {
  background: linear-gradient(135deg, var(--accent-red) 0%, #d81b43 100%);
  color: #fff;
  box-shadow: 0 4px 15px var(--accent-red-glow);
}

.btn-danger:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 42, 95, 0.60);
}

.btn-accent {
  background: rgba(255, 107, 0, 0.15);
  color: var(--accent-orange);
  border: 1px solid rgba(255, 107, 0, 0.3);
  padding: 8px 16px;
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
}

.btn-accent:hover {
  background: var(--accent-orange);
  color: #fff;
  box-shadow: 0 0 10px var(--accent-orange-glow);
}

.btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* ==========================================================================
   Settings Section (Config Panels)
   ========================================================================== */
.settings-section {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.settings-card {
  padding: 24px;
}

/* Skill List Chips style */
.skills-wrapper {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  min-height: 48px;
}

.skill-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 50px;
  padding: 8px 16px;
  cursor: pointer;
  transition: all 0.2s ease;
  user-select: none;
}

.skill-chip:hover {
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08);
}

.skill-chip.active {
  background: rgba(255, 107, 0, 0.1);
  border-color: var(--accent-orange);
  color: var(--accent-orange);
  box-shadow: 0 0 8px rgba(255, 107, 0, 0.15);
}

.skill-chip .skill-name {
  font-size: 0.95rem;
  font-weight: 700;
}

.skill-chip .delete-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1.1rem;
  font-weight: 300;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  transition: all 0.2s ease;
}

.skill-chip .delete-btn:hover {
  color: var(--accent-red);
  background: rgba(255, 42, 95, 0.1);
}

/* Add Skill Form */
.add-skill-form {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}

.add-skill-form input {
  flex: 1;
  background: rgba(10, 12, 16, 0.5);
  border: 1px solid var(--border-color);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--border-radius-sm);
  font-family: inherit;
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--transition-speed);
}

.add-skill-form input:focus {
  border-color: var(--accent-orange);
  box-shadow: 0 0 8px var(--accent-orange-glow);
}

/* Grids & Forms */
.form-group-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 16px;
  margin-top: 12px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 700;
  letter-spacing: 0.5px;
}

.form-group input,
.form-group select {
  background: rgba(10, 12, 16, 0.5);
  border: 1px solid var(--border-color);
  color: #fff;
  padding: 10px 12px;
  border-radius: var(--border-radius-sm);
  font-family: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition-speed);
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--accent-orange);
}

.number-input-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
}

.number-input-wrapper input {
  width: 70px;
  text-align: center;
}

.number-input-wrapper .unit {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Sliders */
.slider-group {
  margin-top: 14px;
}

.slider-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 700;
  margin-bottom: 6px;
}

.slider-label span:last-child {
  color: var(--accent-orange);
  font-family: var(--font-numeric);
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  outline: none;
  transition: background 0.3s;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-orange);
  cursor: pointer;
  box-shadow: 0 0 10px var(--accent-orange-glow);
  transition: transform 0.1s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Mobile Friendly overrides */
@media (max-width: 600px) {
  body {
    padding: 8px;
  }
  .app-container {
    padding: 12px;
  }
  .logo-text {
    font-size: 2.2rem;
  }
  .timer-text {
    font-size: 4rem;
  }
  .combo-text {
    font-size: 2rem;
  }
  .btn-lg {
    padding: 14px 18px;
    font-size: 0.95rem;
  }
}