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

[hidden] { display: none !important; }

:root {
  --bg: #f2f2f7;
  --surface: #ffffff;
  --primary: #007aff;
  --primary-dim: rgba(0, 122, 255, 0.12);
  --green: #34c759;
  --green-dim: rgba(52, 199, 89, 0.12);
  --text: #1c1c1e;
  --text-secondary: #8e8e93;
  --separator: rgba(60, 60, 67, 0.13);
  --radius-card: 20px;
  --radius-btn: 14px;
}

html {
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100%;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.app {
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
  padding-bottom: env(safe-area-inset-bottom, 0px);
}

/* ── Header ─────────────────────────────────────────── */

.app-header {
  padding: 16px 20px 14px;
  padding-top: calc(16px + env(safe-area-inset-top, 0px));
  background: rgba(242, 242, 247, 0.85);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--separator);
  text-align: center;
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header h1 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.3px;
  color: var(--text);
}

/* ── Main layout ────────────────────────────────────── */

.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 28px 20px 24px;
}

/* ── Upload section ─────────────────────────────────── */

.upload-section {
  flex: 1;
  display: flex;
}

.upload-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: var(--surface);
  border: 2px dashed var(--separator);
  border-radius: var(--radius-card);
  padding: 48px 24px;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: border-color 0.15s ease, background 0.15s ease;
  min-height: 300px;
  user-select: none;
}

.upload-area:active {
  background: var(--primary-dim);
  border-color: var(--primary);
  border-style: solid;
}

.upload-icon-wrap {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--primary-dim);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 6px;
}

.upload-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--primary);
  letter-spacing: -0.3px;
}

.upload-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.4;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ── Editor section ─────────────────────────────────── */

.editor-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.editor-canvas-wrap {
  border-radius: var(--radius-card);
  overflow: hidden;
  background: #000;
  line-height: 0;
  width: 100%;
}

#editorCanvas {
  display: block;
  width: 100%;
  touch-action: none;
  cursor: grab;
  user-select: none;
  -webkit-user-select: none;
}

#editorCanvas:active {
  cursor: grabbing;
}

.editor-actions {
  display: flex;
  gap: 12px;
  width: 100%;
  max-width: 340px;
}

.editor-actions .btn {
  flex: 1;
}

/* ── Result section ─────────────────────────────────── */

.result-section {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 28px;
}

.result-wrapper {
  width: min(300px, 80vw);
  height: min(300px, 80vw);
  border-radius: 50%;
  overflow: hidden;
  box-shadow:
    0 2px 8px rgba(0, 0, 0, 0.08),
    0 12px 40px rgba(0, 0, 0, 0.16);
  flex-shrink: 0;
}

.result-wrapper img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

/* ── Action bar ─────────────────────────────────────── */

.action-bar {
  display: flex;
  gap: 12px;
  width: 100%;
  max-width: 340px;
}

.action-bar .btn {
  flex: 1;
}

/* ── Buttons ────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 0 20px;
  height: 52px;
  border-radius: var(--radius-btn);
  font-size: 16px;
  font-weight: 600;
  font-family: inherit;
  letter-spacing: -0.2px;
  border: none;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: opacity 0.12s ease, transform 0.1s ease;
  white-space: nowrap;
}

.btn:active {
  opacity: 0.72;
  transform: scale(0.97);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-secondary {
  background: var(--green-dim);
  color: var(--green);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
  height: 44px;
}

/* ── Loading overlay ────────────────────────────────── */

.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(242, 242, 247, 0.75);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
}

.spinner {
  width: 44px;
  height: 44px;
  border: 3.5px solid rgba(0, 122, 255, 0.2);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ── Toast ──────────────────────────────────────────── */

.toast {
  position: fixed;
  bottom: calc(32px + env(safe-area-inset-bottom, 0px));
  left: 50%;
  transform: translateX(-50%) translateY(0);
  background: rgba(28, 28, 30, 0.88);
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  padding: 10px 18px;
  border-radius: 20px;
  white-space: nowrap;
  pointer-events: none;
  animation: toast-in 0.2s ease, toast-out 0.2s ease 1.8s forwards;
  z-index: 100;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(-50%) translateY(8px); }
  to   { opacity: 1; transform: translateX(-50%) translateY(0); }
}

@keyframes toast-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

/* ── Responsive tweaks ──────────────────────────────── */

@media (min-width: 480px) {
  .app-main {
    max-width: 420px;
    margin: 0 auto;
    width: 100%;
  }
}