:root {
  color-scheme: light;
  --bg: #fbfbfa;
  --panel: #ffffff;
  --panel-soft: #f4f4f2;
  --text: #171717;
  --muted: #70706c;
  --border: #e4e2de;
  --accent: #0f766e;
  --accent-soft: #e0f2ef;
  --code-bg: #f2f5f6;
  --shadow: 0 16px 36px rgba(23, 23, 23, 0.08);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

body {
  margin: 0;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
}

button,
textarea,
select,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

.app-shell {
  display: flex;
  width: 100%;
  height: 100%;
  min-height: 0;
  flex-direction: column;
  background: var(--bg);
  overflow: hidden;
}

.topbar {
  position: relative;
  flex: 0 0 auto;
  z-index: 30;
  display: grid;
  min-height: calc(58px + var(--safe-top));
  grid-template-columns: minmax(44px, 1fr) auto auto;
  align-items: center;
  gap: 8px;
  padding:
    calc(8px + var(--safe-top))
    max(12px, var(--safe-right))
    8px
    max(12px, var(--safe-left));
  border-bottom: 1px solid var(--border);
  background: rgba(251, 251, 250, 0.96);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  min-width: 0;
  flex-direction: column;
  justify-content: center;
  line-height: 1.05;
}

.brand-title {
  overflow: hidden;
  color: var(--text);
  font-size: 17px;
  font-weight: 720;
  letter-spacing: 0;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: color 140ms ease, transform 140ms ease;
  user-select: none;
}

.brand-title.is-secret-tapped {
  color: #be123c;
  transform: translateY(-1px) scale(1.04);
}

.save-state {
  margin-top: 4px;
  overflow: hidden;
  color: var(--muted);
  font-size: 11px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.segmented {
  display: flex;
  flex: 0 0 auto;
  gap: 2px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel-soft);
}

.segment {
  display: inline-grid;
  place-items: center;
  height: 34px;
  min-width: 48px;
  padding: 0 10px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 14px;
  font-weight: 620;
}

.segment.is-active {
  background: var(--panel);
  box-shadow: 0 1px 3px rgba(23, 23, 23, 0.08);
  color: var(--text);
}

.top-actions {
  display: flex;
  flex: 0 0 auto;
  gap: 6px;
}

.icon-button,
.tool-button {
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
  line-height: 1;
}

.icon-button {
  width: 36px;
  height: 36px;
  font-size: 20px;
  font-weight: 520;
}

.button-icon {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.8;
}

.tool-icon {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.65;
}

.table-tool .tool-icon {
  width: 21px;
  height: 21px;
}

.icon-button:active,
.tool-button:active,
.segment:active {
  transform: translateY(1px);
}

.workspace {
  display: grid;
  flex: 1 1 0;
  min-height: 0;
  background: var(--panel);
}

.workspace[data-view="edit"],
.workspace[data-view="preview"] {
  grid-template-rows: minmax(0, 1fr);
}

.workspace[data-view="split"] {
  grid-template-rows: minmax(0, 1fr) minmax(0, 1fr);
}

.workspace[data-view="edit"] .preview-panel,
.workspace[data-view="preview"] .editor-panel {
  display: none;
}

.workspace[data-view="split"] .editor-panel {
  border-bottom: 1px solid var(--border);
}

.editor-panel,
.preview-panel {
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}

.editor {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  resize: none;
  border: 0;
  outline: 0;
  background: var(--panel);
  color: var(--text);
  caret-color: var(--accent);
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
  font-size: 16px;
  line-height: 1.7;
  padding:
    18px
    max(16px, var(--safe-right))
    24px
    max(16px, var(--safe-left));
  tab-size: 2;
}

.editor::placeholder {
  color: #a4a19a;
}

.preview-panel {
  background: var(--panel);
  overflow: hidden;
}

.markdown-body {
  width: 100%;
  height: 100%;
  overflow: auto;
  padding:
    20px
    max(18px, var(--safe-right))
    calc(24px + var(--safe-bottom))
    max(18px, var(--safe-left));
  color: var(--text);
  font-size: 16px;
  line-height: 1.75;
  -webkit-overflow-scrolling: touch;
}

.markdown-body > :first-child {
  margin-top: 0;
}

.markdown-body > :last-child {
  margin-bottom: 0;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  margin: 1.65em 0 0.65em;
  color: var(--text);
  font-weight: 760;
  letter-spacing: 0;
  line-height: 1.24;
}

.markdown-body h1 {
  padding-bottom: 0.32em;
  border-bottom: 1px solid var(--border);
  font-size: 1.7rem;
}

.markdown-body h2 {
  font-size: 1.35rem;
}

.markdown-body h3 {
  font-size: 1.12rem;
}

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body pre,
.markdown-body table,
.markdown-body .katex-display,
.markdown-body .mermaid {
  margin: 0.88em 0;
}

.markdown-body ul,
.markdown-body ol {
  padding-left: 1.35em;
}

.markdown-body .task-list-item {
  list-style: none;
  margin-left: -1.15em;
}

.markdown-body .task-list-checkbox {
  width: 1em;
  height: 1em;
  margin: 0 0.45em 0 0;
  accent-color: var(--accent);
  vertical-align: -0.12em;
}

.markdown-body a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.markdown-body blockquote {
  padding: 0.2em 0 0.2em 0.9em;
  border-left: 3px solid var(--accent);
  color: #42423f;
}

.markdown-body code {
  border: 1px solid #e2e8e8;
  border-radius: 5px;
  background: var(--code-bg);
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
  font-size: 0.92em;
  padding: 0.12em 0.35em;
}

.markdown-body pre {
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--code-bg);
  padding: 14px;
  -webkit-overflow-scrolling: touch;
}

.markdown-body pre code {
  border: 0;
  background: transparent;
  padding: 0;
}

.markdown-body table {
  display: block;
  width: 100%;
  overflow: auto;
  border-collapse: collapse;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
}

.markdown-body th {
  background: var(--panel-soft);
}

.markdown-body img,
.markdown-body svg {
  max-width: 100%;
  height: auto;
}

.markdown-body .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.2em 0;
  -webkit-overflow-scrolling: touch;
}

.markdown-body .mermaid {
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #ffffff;
  padding: 12px;
  text-align: center;
  -webkit-overflow-scrolling: touch;
}

.md-toolbar {
  position: relative;
  flex: 0 0 auto;
  z-index: 40;
  padding:
    8px
    max(10px, var(--safe-right))
    calc(8px + var(--safe-bottom))
    max(10px, var(--safe-left));
  border-top: 1px solid var(--border);
  background: rgba(251, 251, 250, 0.98);
  box-shadow: 0 -10px 24px rgba(23, 23, 23, 0.07);
  backdrop-filter: blur(18px);
}

body[data-mode="preview"] .md-toolbar {
  display: none;
}

.toolbar-scroll {
  display: flex;
  gap: 7px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.toolbar-scroll::-webkit-scrollbar {
  display: none;
}

.tool-button {
  flex: 0 0 42px;
  width: 42px;
  height: 42px;
  color: #252522;
  font-size: 14px;
  font-weight: 680;
  letter-spacing: 0;
  white-space: nowrap;
}

.tool-button.strong {
  font-weight: 860;
}

.tool-button.italic {
  font-family: Georgia, serif;
  font-style: italic;
}

.tool-button.mono {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
}

.tool-button.math {
  color: #8a5a00;
}

.tool-button.table-tool {
  flex-basis: 46px;
  width: 46px;
}

.tool-separator {
  flex: 0 0 1px;
  width: 1px;
  height: 28px;
  margin: 7px 1px;
  background: var(--border);
}

.toast {
  position: fixed;
  top: calc(64px + env(safe-area-inset-top));
  left: 50%;
  z-index: 120;
  max-width: min(320px, calc(100vw - 32px));
  transform: translate(-50%, -10px);
  border: 1px solid rgba(23, 23, 23, 0.08);
  border-radius: 8px;
  background: rgba(23, 23, 23, 0.86);
  color: #ffffff;
  font-size: 13px;
  font-weight: 680;
  opacity: 0;
  padding: 9px 12px;
  pointer-events: none;
  text-align: center;
  transition: opacity 160ms ease, transform 160ms ease;
  white-space: nowrap;
}

.toast.is-visible {
  transform: translate(-50%, 0);
  opacity: 1;
}

.toast.is-success {
  border-color: rgba(15, 118, 110, 0.18);
  background: #0f766e;
  color: #ffffff;
}

.toast.is-error {
  border-color: rgba(185, 28, 28, 0.18);
  background: #b91c1c;
  color: #ffffff;
}

.settings-backdrop {
  position: fixed;
  inset: 0;
  z-index: 70;
  background: rgba(23, 23, 23, 0.18);
}

.settings-panel,
.picker-panel {
  position: fixed;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 80;
  max-height: min(82dvh, 620px);
  transform: translateY(100%);
  overflow: auto;
  border-top: 1px solid var(--border);
  background: var(--panel);
  box-shadow: var(--shadow);
  padding: 14px max(16px, env(safe-area-inset-right)) calc(18px + env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
  transition: transform 180ms ease;
  -webkit-overflow-scrolling: touch;
}

.settings-panel.is-open {
  transform: translateY(0);
}

.picker-panel.is-open {
  transform: translateY(0);
}

.picker-backdrop {
  position: fixed;
  inset: 0;
  z-index: 90;
  background: rgba(23, 23, 23, 0.2);
}

.picker-panel {
  z-index: 100;
  max-height: min(74dvh, 520px);
}

.settings-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.settings-header h2 {
  margin: 0;
  font-size: 19px;
  font-weight: 760;
  letter-spacing: 0;
}

.panel-close {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
}

.settings-form {
  display: grid;
  gap: 12px;
}

.field-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 10px;
}

.field {
  display: grid;
  min-width: 0;
  gap: 6px;
}

.field span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 680;
}

.field input,
.field select {
  width: 100%;
  min-width: 0;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel-soft);
  color: var(--text);
  font: inherit;
  font-size: 15px;
  outline: 0;
  padding: 0 11px;
}

.field input:focus,
.field select:focus {
  border-color: var(--accent);
  background: #ffffff;
}

.cloud-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.primary-button,
.secondary-button,
.text-button {
  min-height: 40px;
  border-radius: 8px;
  cursor: pointer;
  font: inherit;
  font-weight: 680;
}

.primary-button {
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #ffffff;
}

.cloud-button,
.picker-button {
  display: inline-grid;
  place-items: center;
}

.cloud-button {
  min-height: 44px;
}

.secondary-button,
.text-button {
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
}

.text-button {
  min-height: 34px;
  padding: 0 12px;
}

.settings-note {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.picker-body {
  display: grid;
  gap: 12px;
}

.picker-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 14px;
}

.secret-backdrop {
  position: fixed;
  inset: 0;
  z-index: 140;
  display: grid;
  place-items: center;
  background: rgba(23, 23, 23, 0.28);
  opacity: 0;
  padding: 20px;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.secret-backdrop.is-open {
  opacity: 1;
  pointer-events: auto;
}

.secret-card {
  width: min(320px, calc(100vw - 40px));
  border: 1px solid rgba(190, 18, 60, 0.16);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 18px 46px rgba(23, 23, 23, 0.18);
  padding: 18px;
  text-align: center;
  transform: translateY(8px) scale(0.98);
  transition: transform 180ms ease;
}

.secret-backdrop.is-open .secret-card {
  transform: translateY(0) scale(1);
}

.secret-kicker {
  margin: 0 0 6px;
  color: #be123c;
  font-size: 11px;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.secret-card h2 {
  margin: 0 0 14px;
  font-size: 20px;
  letter-spacing: 0;
}

.secret-input {
  width: 100%;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff7f8;
  color: var(--text);
  font: inherit;
  font-size: 20px;
  font-weight: 760;
  letter-spacing: 0.22em;
  outline: 0;
  padding: 0 13px;
  text-align: center;
}

.secret-input:focus {
  border-color: #be123c;
  background: #ffffff;
}

.secret-input.is-shaking {
  animation: secretShake 260ms ease;
}

.secret-note {
  min-height: 18px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.secret-note.is-error {
  color: #b91c1c;
}

.romance-sky {
  position: fixed;
  inset: 0;
  z-index: 150;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(12, 10, 26, 0.9), rgba(83, 19, 57, 0.78));
  opacity: 0;
  pointer-events: none;
  transition: opacity 600ms ease;
}

.romance-sky.is-active {
  opacity: 1;
  pointer-events: auto;
}

.romance-glow {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 50% 35%, rgba(255, 226, 236, 0.22), transparent 30%),
    linear-gradient(115deg, rgba(244, 114, 182, 0.12), transparent 45%, rgba(45, 212, 191, 0.12));
}

.romance-message {
  position: absolute;
  right: 22px;
  bottom: calc(92px + env(safe-area-inset-bottom));
  left: 22px;
  color: #fff7fb;
  text-align: center;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.28);
}

.romance-names {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(10px, 4vw, 18px);
  margin-bottom: 10px;
  color: #fff1f4;
  font-size: clamp(28px, 10vw, 46px);
  font-weight: 860;
  letter-spacing: 0.03em;
}

.romance-heart {
  display: inline-block;
  color: #f45f78;
  font-size: 1.06em;
  line-height: 1;
  text-shadow:
    0 0 12px rgba(244, 95, 120, 0.44),
    0 4px 18px rgba(244, 95, 120, 0.24);
  transform-origin: center;
  animation: heartPulse 1450ms ease-in-out infinite;
}

.romance-message strong {
  display: block;
  font-size: clamp(18px, 6.4vw, 28px);
  font-weight: 760;
  letter-spacing: 0;
  line-height: 1.28;
}

.firework-particle {
  position: absolute;
  top: var(--top);
  left: var(--left);
  width: 4px;
  height: 4px;
  border-radius: 999px;
  background: hsl(var(--hue), 92%, 70%);
  box-shadow: 0 0 12px hsl(var(--hue), 92%, 70%);
  opacity: 0;
  animation: fireworkBloom 1200ms ease-out var(--delay) forwards;
}

.floating-heart {
  position: absolute;
  top: var(--top);
  left: var(--left);
  width: var(--size);
  height: var(--size);
  background: #fb7185;
  opacity: 0;
  transform: rotate(-45deg) scale(0.4);
  animation: heartFloat var(--duration) ease-in var(--delay) forwards;
  box-shadow: 0 0 18px rgba(251, 113, 133, 0.42);
}

.floating-heart::before,
.floating-heart::after {
  position: absolute;
  width: var(--size);
  height: var(--size);
  border-radius: 50%;
  background: inherit;
  content: "";
}

.floating-heart::before {
  top: calc(var(--size) * -0.5);
  left: 0;
}

.floating-heart::after {
  top: 0;
  left: calc(var(--size) * 0.5);
}

@keyframes secretShake {
  0%,
  100% {
    transform: translateX(0);
  }

  25% {
    transform: translateX(-5px);
  }

  75% {
    transform: translateX(5px);
  }
}

@keyframes heartPulse {
  0%,
  100% {
    transform: scale(1);
  }

  45% {
    transform: scale(1.12);
  }
}

@keyframes fireworkBloom {
  0% {
    opacity: 0;
    transform: rotate(var(--angle)) translateX(0) scale(0.2);
  }

  14% {
    opacity: 1;
  }

  100% {
    opacity: 0;
    transform: rotate(var(--angle)) translateX(var(--distance)) scale(0);
  }
}

@keyframes heartFloat {
  0% {
    opacity: 0;
    transform: translate(0, 0) rotate(-45deg) scale(0.35);
  }

  12% {
    opacity: 0.92;
  }

  100% {
    opacity: 0;
    transform: translate(var(--drift), -52vh) rotate(-45deg) scale(1.08);
  }
}

@media (max-width: 430px) {
  .topbar {
    grid-template-columns: auto 1fr auto;
  }

  .brand {
    width: 42px;
  }

  .save-state {
    display: none;
  }

  .brand-title {
    font-size: 16px;
  }

  .segmented {
    justify-self: center;
  }

  .segment {
    min-width: 44px;
    padding: 0 8px;
  }

  .icon-button {
    width: 34px;
    height: 34px;
  }
}

@media (max-width: 370px) {
  .split-only {
    display: none;
  }

  .top-actions {
    gap: 4px;
  }

  .icon-button {
    width: 31px;
    height: 32px;
    font-size: 15px;
  }

  .field-row {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 900px) {
  .workspace[data-view="split"] {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    grid-template-rows: minmax(0, 1fr);
  }

  .workspace[data-view="split"] .editor-panel {
    display: block;
    border-bottom: 0;
    border-right: 1px solid var(--border);
  }

  .workspace[data-view="split"] .preview-panel {
    display: block;
  }

  .workspace[data-view="edit"] .editor-panel,
  .workspace[data-view="preview"] .preview-panel {
    max-width: 920px;
    width: 100%;
    justify-self: center;
  }

  .md-toolbar {
    padding-right: calc(max(10px, var(--safe-right)) + max(0px, (100vw - 760px) / 2));
    padding-left: calc(max(10px, var(--safe-left)) + max(0px, (100vw - 760px) / 2));
  }

  .settings-panel {
    right: max(20px, env(safe-area-inset-right));
    bottom: 76px;
    left: auto;
    width: min(420px, calc(100vw - 40px));
    border: 1px solid var(--border);
    border-radius: 8px;
    transform: translateY(calc(100% + 96px));
  }

  .picker-panel {
    right: max(20px, env(safe-area-inset-right));
    bottom: 76px;
    left: auto;
    width: min(420px, calc(100vw - 40px));
    border: 1px solid var(--border);
    border-radius: 8px;
    transform: translateY(calc(100% + 96px));
  }
}