:root {
  --bg: #0f172a;
  --bg-gradient: radial-gradient(
    1200px 800px at 20% 10%,
    #1e293b 0%,
    #0f172a 55%,
    #0b1120 100%
  );
  --card-bg: rgba(255, 255, 255, 0.04);
  --card-border: rgba(255, 255, 255, 0.08);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --work-color: #f43f5e;
  --work-color-soft: rgba(244, 63, 94, 0.15);
  --break-color: #34d399;
  --break-color-soft: rgba(52, 211, 153, 0.15);
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --radius-lg: 24px;
  --radius-md: 14px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
}

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

body {
  font-family:
    "Inter",
    system-ui,
    -apple-system,
    sans-serif;
  background: var(--bg-gradient);
  background-color: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
  -webkit-font-smoothing: antialiased;
}

.app {
  width: 100%;
  max-width: 420px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 20px;
}

.app-title {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  background: linear-gradient(135deg, #f1f5f9 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.app-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  text-align: center;
  margin-top: -14px;
}

/* Mode Tabs */
.mode-tabs {
  display: flex;
  width: 100%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 999px;
  padding: 4px;
  gap: 4px;
}

.mode-tab {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.25s ease;
}

.mode-tab:hover {
  color: var(--text-primary);
}

.mode-tab.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.4);
}

/* Timer Card */
.timer-card {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 50%;
  box-shadow: var(--shadow);
}

.progress-ring {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.progress-ring-track {
  stroke: rgba(255, 255, 255, 0.08);
}

.progress-ring-bar {
  stroke: var(--work-color);
  stroke-dasharray: 816.8;
  stroke-dashoffset: 0;
  transition:
    stroke-dashoffset 0.5s linear,
    stroke 0.4s ease;
}

.timer-card.break-mode .progress-ring-bar {
  stroke: var(--break-color);
}

.timer-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  z-index: 1;
}

.timer-status {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 4px 14px;
  border-radius: 999px;
}

.timer-time {
  font-size: 3.6rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}

.timer-session {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Controls */
.controls {
  display: flex;
  gap: 12px;
  width: 100%;
}

.btn {
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  padding: 14px 24px;
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-primary {
  flex: 1;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 12px 28px rgba(99, 102, 241, 0.45);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--card-bg);
  color: var(--text-secondary);
  border: 1px solid var(--card-border);
}

.btn-secondary:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.08);
}

.btn-icon {
  font-size: 0.85rem;
}

/* Settings */
.settings {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
}

.setting {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  flex: 1;
}

.setting-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.setting-control {
  display: flex;
  align-items: center;
  gap: 12px;
}

.step-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--card-border);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.step-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.step-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.step-btn:disabled:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--card-border);
  color: var(--text-primary);
}

.setting-value {
  display: flex;
  align-items: baseline;
  gap: 4px;
  min-width: 56px;
  justify-content: center;
}

.setting-value span {
  font-size: 1.6rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.setting-value small {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

.setting-divider {
  width: 1px;
  height: 48px;
  background: var(--card-border);
}

/* Cycles */
.cycles {
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  text-align: center;
}

/* Footer */
.footer {
  width: 100%;
  max-width: 420px;
  margin-top: 28px;
  text-align: center;
}

.footer a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

.footer a:hover {
  color: var(--text-primary);
}

/* Responsive */
@media (max-width: 420px) {
  .timer-time {
    font-size: 3rem;
  }

  .settings {
    padding: 16px;
  }

  .step-btn {
    width: 32px;
    height: 32px;
  }
}