:root {
  --bg-system: #f2f2f7;
  --card-bg: rgba(255, 255, 255, 0.85);
  --accent: #007aff;
  --accent-hover: #0062cc;
  --text-primary: #000000;
  --text-secondary: #8e8e93;
  --border-color: rgba(60, 60, 67, 0.12);
  --input-bg: rgba(118, 118, 128, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-system: #000000;
    --card-bg: #1c1c1e;
    --accent: #0a84ff;
    --accent-hover: #409cff;
    --text-primary: #ffffff;
    --text-secondary: #8e8e93;
    --border-color: rgba(84, 84, 88, 0.36);
    --input-bg: rgba(118, 118, 128, 0.24);
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-system);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 440px;
}

.header {
  text-align: center;
  margin-bottom: 24px;
}

.logo-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 4px;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 400;
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 20px;
  padding: 20px;
  border: 1px solid var(--border-color);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.tabs {
  display: flex;
  background-color: var(--input-bg);
  padding: 2px;
  border-radius: 10px;
  margin-bottom: 16px;
  gap: 2px;
}

.tab-btn {
  flex: 1;
  background: transparent;
  border: none;
  padding: 8px 4px;
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.tab-btn.active {
  background-color: var(--card-bg);
  color: var(--text-primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
}

textarea {
  width: 100%;
  height: 120px;
  background-color: var(--input-bg);
  border: none;
  border-radius: 12px;
  padding: 14px;
  color: var(--text-primary);
  font-size: 15px;
  resize: none;
  outline: none;
  margin-bottom: 12px;
}

.picker-container {
  background-color: var(--input-bg);
  border-radius: 12px;
  padding: 12px 16px;
  margin-bottom: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.picker-label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.picker-wheels {
  display: flex;
  justify-content: space-around;
  align-items: center;
  gap: 8px;
}

.picker-col {
  display: flex;
  align-items: center;
  gap: 4px;
}

.ios-select {
  background: var(--card-bg);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 16px;
  font-weight: 600;
  outline: none;
  cursor: pointer;
  text-align: center;
  appearance: none;
  -webkit-appearance: none;
}

.unit {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
}

.file-picker {
  margin-bottom: 12px;
}

.file-input-hidden {
  display: none;
}

.file-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 14px;
  background-color: var(--input-bg);
  color: var(--text-secondary);
  border-radius: 12px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border: 1px dashed var(--border-color);
  transition: all 0.2s ease;
  overflow: hidden;
}

.file-box:hover {
  background-color: rgba(118, 118, 128, 0.15);
}

.file-box span {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 85%;
}

.clear-file {
  background: rgba(118, 118, 128, 0.25);
  border: none;
  color: var(--text-primary);
  width: 22px;
  height: 22px;
  border-radius: 50%;
  font-size: 14px;
  line-height: 22px;
  text-align: center;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.clear-file:hover {
  background: rgba(255, 59, 48, 0.8);
  color: #fff;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.btn-primary {
  width: 100%;
  background-color: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: 12px;
  padding: 14px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  display: block;
  transition: opacity 0.2s ease;
}

.btn-primary:active {
  opacity: 0.8;
}

.result-box {
  margin-top: 16px;
  padding: 12px;
  background-color: var(--input-bg);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.result-box input {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
}

.hidden {
  display: none !important;
}