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

html, body { 
  color-scheme: dark;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
  color: #fff;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-weight: 200;
  -webkit-font-smoothing: antialiased;
}

.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: env(safe-area-inset-top, 20px) env(safe-area-inset-right, 20px) env(safe-area-inset-bottom, 20px) env(safe-area-inset-left, 20px);
  opacity: 0;
  pointer-events: none;
  transition: none;
}

.screen.active {
  opacity: 1;
  pointer-events: auto;
}

/* iOS Safari install gate */
#install-screen {
  justify-content: flex-start;
  overflow-y: auto;
  padding-top: max(env(safe-area-inset-top, 20px), 32px);
  text-align: center;
}
.install-icon {
  border-radius: 18px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.45);
  margin-bottom: 16px;
}
.install-title {
  font-size: 1.6rem;
  font-weight: 600;
  margin: 0;
}
.install-sub {
  color: #9a9a9a;
  margin: 2px 0 26px;
  font-size: 1rem;
}
.install-lead {
  font-size: 1.1rem;
  margin: 0 0 20px;
}
.install-steps {
  text-align: left;
  max-width: 330px;
  margin: 0 auto;
  padding-left: 26px;
  line-height: 1.65;
  font-size: 1.08rem;
}
.install-steps li {
  margin-bottom: 12px;
}
.install-icon-inline {
  color: #4da3ff;
  vertical-align: -5px;
  margin: 0 2px;
}
.install-hint {
  color: #9a9a9a;
}
.install-return-note {
  max-width: 340px;
  margin: 0 auto 22px;
  padding: 12px 14px;
  border: 1px solid #34506e;
  background: #14202c;
  border-radius: 10px;
  color: #cfe3ff;
  font-size: 0.98rem;
  line-height: 1.45;
}
.install-return-note[hidden] {
  display: none;
}

.screen.fade-in {
  animation: fadeIn 500ms ease forwards;
}

.screen.fade-out {
  animation: fadeOut 500ms ease forwards;
  pointer-events: none;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeOut {
  from { opacity: 1; }
  to { opacity: 0; }
}

/* Start Screen */
#start-screen {
  background: #000;
  gap: 30px;
}

.settings-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  width: 100%;
  max-width: 280px;
}

.setting {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  width: 100%;
}

.setting label {
  font-size: 14px;
  font-weight: 300;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  opacity: 0.6;
}

.setting input {
  width: 100%;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  color: #fff;
  font-family: inherit;
  font-weight: 200;
  font-size: 32px;
  text-align: center;
  padding: 10px;
  outline: none;
  -moz-appearance: textfield;
}

.setting input::-webkit-outer-spin-button,
.setting input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.setting input:focus {
  border-color: rgba(255, 255, 255, 0.5);
}

.preset-buttons {
  display: flex;
  gap: 6px;
  width: 100%;
  margin-top: 4px;
}

.preset-btn {
  font-size: 15px;
  font-weight: 300;
  padding: 12px 0;
  flex: 1;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  letter-spacing: 0;
  text-transform: none;
  opacity: 0.7;
}

.preset-btn:active {
  opacity: 1;
  border-color: rgba(255, 255, 255, 0.5);
}

button {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 30px;
  color: #fff;
  font-family: inherit;
  font-weight: 300;
  font-size: 18px;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 14px 48px;
  cursor: pointer;
  transition: border-color 0.2s, opacity 0.2s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

button:active {
  border-color: rgba(255, 255, 255, 0.6);
}

button:disabled {
  opacity: 0.25;
  cursor: default;
}

#start-btn {
  margin-top: 10px;
}

#start-update-btn {
  display: none;
  margin-top: 12px;
  padding: 10px 24px;
  font-size: 14px;
  letter-spacing: 0.4px;
  text-transform: none;
  opacity: 0.75;
}

.additional-time {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

#additional-display {
  font-size: 28px;
  font-weight: 200;
  font-variant-numeric: tabular-nums;
  opacity: 0.7;
}

.additional-plus-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
}

/* Timer Screen */
#timer-screen {
  background-color: #000;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

#timer-display {
  font-size: 72px;
  font-weight: 200;
  letter-spacing: 2px;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
  font-variant-numeric: tabular-nums;
}

#timer-display.heartbeat {
  animation: heartbeat 1.5s ease-in-out infinite;
}

@keyframes heartbeat {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.timer-buttons {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  margin-top: 40px;
}

.timer-buttons button {
  min-width: 160px;
}

/* Completion Screen */
#complete-screen {
  background: #000;
  gap: 30px;
}

.stats {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  font-size: 18px;
  font-weight: 200;
  opacity: 0.8;
}

.stats .total-time {
  font-size: 48px;
  font-weight: 200;
  opacity: 1;
  margin-bottom: 8px;
}

.log-prompt {
  font-size: 20px;
  font-weight: 300;
  margin-top: 10px;
}

.log-buttons {
  display: flex;
  gap: 20px;
}

.log-buttons button {
  min-width: 100px;
}

/* Hamburger & Close buttons */
.hamburger, .close-btn {
  position: absolute;
  top: env(safe-area-inset-top, 20px);
  right: env(safe-area-inset-right, 20px);
  background: transparent;
  border: none;
  border-radius: 0;
  color: #fff;
  padding: 10px;
  cursor: pointer;
  opacity: 0.6;
  z-index: 10;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-tap-highlight-color: transparent;
  letter-spacing: 0;
  text-transform: none;
  font-size: 16px;
}

.hamburger:active, .close-btn:active {
  opacity: 1;
}

/* Menu Screen */
#menu-screen {
  background: #000;
}

.menu-items {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 36px;
}

.menu-item {
  font-size: 20px;
  font-weight: 300;
  letter-spacing: 0.5px;
  color: #fff;
  opacity: 0.8;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.menu-item:active {
  opacity: 1;
}

.menu-item.menu-ios {
  font-size: 13px;
  font-weight: 300;
  opacity: 0.4;
  cursor: default;
  text-align: center;
  line-height: 1.6;
}

/* Settings Screen */
#settings-screen {
  background: #000;
}

.settings-items {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
  width: 100%;
  max-width: 300px;
}

.sound-setting {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
}

.sound-setting label {
  font-size: 14px;
  font-weight: 300;
  letter-spacing: 0.5px;
  opacity: 0.6;
}

.sound-row {
  display: flex;
  gap: 8px;
  width: 100%;
}

.sound-preview {
  flex: 0 0 42px;
  width: 42px;
  max-width: 42px;
  height: 42px;
  padding: 0;
  background: transparent;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 8px;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-tap-highlight-color: transparent;
  opacity: 0.8;
}

.sound-preview svg {
  flex-shrink: 0;
}

.sound-preview:active {
  opacity: 1;
}

.sound-setting select {
  flex: 1;
  min-width: 0;
  padding: 10px 12px;
  background: #222;
  color: #fff;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 8px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 300;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  cursor: pointer;
}

.sound-setting select option {
  background: #222;
  color: #fff;
}

.email-dialog-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(0, 0, 0, 0.82);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 200ms ease, visibility 0s linear 200ms;
  z-index: 40;
}

.email-dialog-overlay.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition-delay: 0s;
}

.email-dialog {
  width: min(100%, 420px);
  background: #101010;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 18px;
  padding: 26px 22px 20px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}

.email-dialog h2 {
  font-size: 30px;
  font-weight: 200;
  line-height: 1.15;
  margin-bottom: 14px;
}

.email-dialog p {
  font-size: 15px;
  font-weight: 300;
  line-height: 1.55;
  opacity: 0.72;
  margin-bottom: 18px;
}

.email-dialog input {
  width: 100%;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 10px;
  color: #fff;
  font-family: inherit;
  font-size: 17px;
  font-weight: 300;
  padding: 14px 16px;
  outline: none;
}

.email-dialog input:focus {
  border-color: rgba(255, 255, 255, 0.5);
}

.email-dialog-message {
  min-height: 20px;
  font-size: 13px;
  font-weight: 300;
  color: #ffb3b3;
  margin-top: 10px;
}

.email-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 18px;
}

.email-dialog-actions button {
  min-width: 96px;
  padding: 12px 20px;
  border-radius: 999px;
  text-transform: none;
  letter-spacing: 0.3px;
}

.email-dialog-submit {
  background: #fff;
  color: #000;
  border-color: #fff;
}

/* Stats Screen */
#stats-screen {
  background: #000;
  overflow-y: auto;
  justify-content: flex-start;
  padding-top: calc(env(safe-area-inset-top, 20px) + 50px);
  padding-bottom: 40px;
}

.stats-summary {
  display: flex;
  flex-direction: column;
  gap: 14px;
  width: 100%;
  max-width: 320px;
  margin-bottom: 30px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  width: 100%;
  font-size: 15px;
  font-weight: 200;
}

.stat-label {
  opacity: 0.6;
}

.stat-value {
  font-weight: 300;
  text-align: right;
}

.stats-date-picker {
  width: 100%;
  max-width: 320px;
  margin-bottom: 20px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  color: #fff;
  font-family: inherit;
  font-weight: 200;
  font-size: 16px;
  padding: 10px 14px;
  outline: none;
  color-scheme: dark;
}

.stats-date-picker:focus {
  border-color: rgba(255, 255, 255, 0.5);
}

.session-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  max-width: 320px;
}

.session-entry {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 14px;
}

.session-entry-date {
  font-size: 14px;
  font-weight: 300;
  opacity: 0.9;
  margin-bottom: 4px;
}

.session-entry-details {
  font-size: 13px;
  font-weight: 200;
  opacity: 0.5;
  line-height: 1.5;
}

/* Graphs */
.graph {
  width: 100%;
  max-width: 320px;
  margin-bottom: 24px;
}

.graph-title {
  font-size: 13px;
  text-transform: uppercase;
  opacity: 0.5;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
  text-align: center;
}

.graph-body {
  position: relative;
}

.graph-y-tick {
  position: absolute;
  left: 2px;
  font-size: 9px;
  opacity: 0.4;
  transform: translateY(-50%);
  line-height: 1;
  z-index: 1;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.8);
}

.graph-gridline {
  position: absolute;
  left: 0;
  right: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  pointer-events: none;
}

.graph-bars {
  display: flex;
  flex-direction: row;
  align-items: stretch;
  height: 100px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  gap: 2px;
}

.graph-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
}

.graph-bar {
  width: 100%;
  background: rgba(255, 255, 255, 0.4);
  border-radius: 2px 2px 0 0;
  min-height: 1px;
}

.graph-labels {
  display: flex;
  flex-direction: row;
  gap: 2px;
  margin-top: 4px;
}

.graph-label {
  flex: 1;
  font-size: 9px;
  opacity: 0.4;
  text-align: center;
}

#detail-screen {
  background: #000;
  overflow-y: auto;
  justify-content: flex-start;
  padding-top: calc(env(safe-area-inset-top, 20px) + 50px);
  padding-bottom: 40px;
}

#detail-btn {
  margin-top: 10px;
}