@import url('https://fonts.googleapis.com/css?family=Noto+Sans:400,700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Oxanium&display=swap');

/* Generic defaults (overridden by theme files) */
:root {
  --background: #f5f5f5;
  --foreground: #333;
  --primary: #1e81b0;
  --primary-hover: #166191;
  --card-bg: #ffffff;
  --card-shadow: 0 4px 16px rgba(0,0,0,0.15);
  --card-border: 1px solid transparent;
  --text-primary: #1e81b0;
  --text-secondary: #ffffff;
  --accent: #ffe082;
  --border-radius: 18px;
  --border-radius-sm: 6px;
  --shadow-sm: 0 4px 16px rgba(0,0,0,0.15);
  --spacing-xs: 5px;
  --spacing-sm: 12px;
  --spacing-md: 24px;
  --spacing-lg: 36px;
  --font-family: 'Noto Sans', Arial, sans-serif;
  --font-weight-normal: 400;
  --font-weight-bold: 700;
  --header-text: #333;
  --header-link: #007bff;
  --header-link-hover: #0056b3;
}

/* Shared styles using variables */
* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  font-family: var(--font-family);
  background: var(--background);
  margin: 0;
  padding: 0;
  color: var(--foreground);
  transition: background 0.3s ease, color 0.3s ease;
}

.main-layout {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

h1 {
  font-size: 0.3em;
  text-align: center;
  margin-top: var(--spacing-lg);
  margin-bottom: 0;
  font-family: var(--font-family);
  font-weight: var(--font-weight-bold);
}

/* Header */
.header {
  padding: 20px;
  max-width: 400px;
  margin: 0 auto;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.header h1 {
  font-size: 18px;
  font-weight: 400;
  color: var(--header-text); 
  font-family: var(--font-family);
}

.app-title {
  font-size: 20px;
  font-weight: 400;
  color: var(--header-text);
  margin: 0;
  font-family: var(--font-family);
}

.header-links {
  display: flex;
  gap: 14px;
}

.header-links a {
  color: var(--header-link);
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: 500;
  font-family: var(--font-family);
}

.header-links a:hover {
  color: var(--header-link-hover);
  text-decoration: underline;
}

#game-container {
  margin-top: var(--spacing-lg);
  margin-bottom: 0;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Flip card */
.flip-card-outer {
  width: 340px;
  max-width: 95vw;
  margin: 0;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 180px;
  transition: min-height 0.3s;
}

/* Container only sets perspective, no border/shadow */
.flip-card {
  width: 100%;
  position: relative;
  min-height: 180px;
  perspective: 1200px;
}

/* Faces: rotate and own border/shadow */
.flip-card-inner {
  width: 100%;
  min-height: 180px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.8,1,.2,1);
}

/* When flipped, rotate the faces wrapper */
.flip-card.flipped .flip-card-inner {
  transform: rotateY(180deg);
}

.flip-card-front,
.flip-card-back {
  position: absolute;
  inset: 0;
  width: 100%;

  border-radius: var(--border-radius);
  border: var(--card-border, 1px solid transparent);
  box-shadow: var(--card-shadow, var(--shadow-sm));
  background: var(--card-bg);

  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 1.4em;
  padding: 32px 24px;
  font-weight: var(--font-weight-normal);
  font-family: var(--font-family);
  box-sizing: border-box;
  word-break: break-word;
  min-height: 180px;
  backface-visibility: hidden;
  transition: background 0.3s;
}

.flip-card-front {
  color: var(--text-primary);
  background: var(--card-bg);
  z-index: 2;
}

.flip-card-back {
  background: var(--primary);
  color: var(--text-secondary);
  transform: rotateY(180deg);
  z-index: 1;
}

.back-english {
  font-size: 0.9em;
  color: var(--accent);
  background: rgba(255,255,255,0.07);
  border-radius: var(--border-radius-sm);
  margin-bottom: 12px;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-weight: var(--font-weight-normal);
  width: 100%;
  text-align: center;
  box-sizing: border-box;
  font-family: var(--font-family);
}

.back-meaning {
  font-size: 0.7em;
  color: var(--text-secondary);
  margin-bottom: 0;
  width: 100%;
  text-align: center;
  box-sizing: border-box;
  font-family: var(--font-family);
  font-weight: var(--font-weight-normal);
}

#next-btn {
  padding: 12px 40px;
  font-size: 1.1em;
  border-radius: var(--button-radius, 10px);
  border: none;
  background: var(--primary);
  color: var(--text-secondary);
  cursor: pointer;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  display: block;
  font-family: var(--font-family);
  font-weight: var(--font-weight-normal);
  transition: background 0.2s;
}

#next-btn:hover {
  background: var(--primary-hover);
}

/* Theme switcher */
.theme-switcher {
  display: flex;
  gap: 0.5rem;
  margin: var(--spacing-lg) 0;
  justify-content: center;
}

.theme-switcher button {
  padding: 0.5rem 1rem;
  border: 1px solid var(--primary);
  background: var(--background);
  color: var(--foreground);
  cursor: pointer;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-family);
}

/* Fixed gray bar for theme buttons */
.theme-bar {
  position: sticky;          /* or fixed if you want it always visible */
  top: 0;
  z-index: 10;
  width: 100%;
  background: #e5e5e5;       /* independent of theme */
  padding: 12px 20px;
  display: flex;
  justify-content: center;
  gap: 12px;
}

/* Base style for theme buttons (not using theme vars) */
.theme-btn {
  min-width: 110px;
  padding: 8px 16px;
  font-family: var(--font-family);
  font-size: 14px;
  border-radius: 4px;
  border: 2px solid #ccc;
  background: #fff;
  color: #333;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

/* Default theme button look */
.theme-btn-default {
  border-radius: 10px;
  border-color: #1e81b0;
  color: #1e81b0;
  font-family: 'Noto Sans', Arial, sans-serif;

}

/* Brutalist theme button look */
.theme-btn-brutalist {
  border-radius: 0;
  border-color: rgb(0, 0, 0);
  color: #d33;
  box-shadow: 2px 2px 0px hsl(0 0% 0% / 1);
  font-family: 'Geo', Courier, monospace;
}

/* Hover states */
.theme-btn-default:hover {
  background: #c3ecff;
}

.theme-btn-brutalist:hover {
  background: #ffe1e1;
}