@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap");

/* --- CSS VARIABLES FOR THEMES --- */
:root {
  --bg-url: url("/res/image/cover-light.jfif");
  --card-bg-color: rgba(255, 255, 255, 0.75);
  --card-border-color: rgba(0, 0, 0, 0.1);
  --text-color: #111111;
  --text-muted-color: #555555;
  --wrapper-bg-color: rgba(255, 255, 255, 0.4);
  --select-option-bg: #f0f0f0;
  --btn-check-bg: rgba(0, 0, 0, 0.05);
  --dropdown-arrow-color: "%23000000";
}

[data-bs-theme="dark"] {
  --bg-url: url("/res/image/cover-dark.jfif");
  --card-bg-color: rgba(30, 30, 30, 0.8);
  --card-border-color: rgba(255, 255, 255, 0.1);
  --text-color: #f1f1f1;
  --text-muted-color: #aaaaaa;
  --wrapper-bg-color: rgba(0, 0, 0, 0.6);
  --select-option-bg: #333333;
  --btn-check-bg: rgba(255, 255, 255, 0.05);
  --dropdown-arrow-color: "%23ffffff"; /* white encoded */
}

body {
  font-family: "Poppins", sans-serif;
  background-image: var(--bg-url);
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
  color: var(--text-color);
  transition: background-image 0.5s ease-in-out;
}

.main-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.glass-card {
  background: var(--card-bg-color);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border: 1px solid var(--card-border-color);
  border-radius: 20px;
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
  transition: background-color 0.5s ease, border-color 0.5s ease;
}

h1 {
  font-weight: 600;
}

.btn-check:checked + .btn-outline-primary {
  background-color: var(--btn-check-bg) !important;
  border-color: var(--card-border-color) !important;
  color: var(--text-color) !important;
  box-shadow: none;
}
.btn-outline-primary {
  border-color: var(--card-border-color);
  color: var(--text-muted-color);
}
.btn-outline-primary:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: var(--card-border-color);
  color: var(--text-color);
}
.btn-group .btn {
  transition: all 0.2s ease-in-out;
}

.conversion-wrapper {
  background: var(--wrapper-bg-color);
  border-radius: 15px;
  padding: 1rem;
  transition: background-color 0.5s ease;
}
.conversion-area {
  display: flex;
  gap: 10px;
}

.form-control,
.form-select {
  background-color: transparent;
  color: var(--text-color);
  font-size: 1.5rem !important;
  font-weight: 600;
}
.form-control:focus,
.form-select:focus {
  background-color: transparent;
  color: var(--text-color);
  box-shadow: none;
}
.form-select {
  width: 160px;
  font-size: 1rem !important;
  font-weight: 400;
}
.form-select option {
  background-color: var(--select-option-bg);
  color: var(--text-color);
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] {
  -moz-appearance: textfield;
  appearance: textfield;
}

.result-text {
  color: var(--text-muted-color);
  padding-top: 0.6rem;
  background-color: var(--card-bg-color);
  border: none;
}

.btn-icon {
  color: var(--text-color);
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--card-border-color);
  transition: all 0.2s ease;
}
.btn-icon:hover {
  background: rgba(255, 255, 255, 0.2);
  color: var(--text-color);
}
.btn-icon:active {
  transform: scale(0.95);
}

.formula-text {
  font-size: 0.85rem;
  color: var(--text-muted-color);
  min-height: 20px;
}

.theme-toggle-button {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1050;
  color: var(--text-color);
  background: var(--card-bg-color);
  backdrop-filter: blur(10px);
  border-color: var(--card-border-color);
}