@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700&display=swap");

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

:root {
  --bg-main: #121212;
  --bg-card: #1e1e1e;
  --bg-panel: #252525;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0a0;
  --accent-gold: #d4af37;
  --accent-blue: #5c85d6;
  --accent-red: #d65c5c;
  --board-light: #9ca3af;
  --board-dark: #4b5563;
  --square-size: clamp(45px, 16vh, 100px); /* Responsive to height */
  --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.5);
  --border-color: #333;
}

body {
  font-family: "Poppins", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden; /* Prevent scrolling in iframe */
}

/* --- Start Screen --- */
.start-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--bg-main);
  background-image: radial-gradient(circle at center, #1a1a1a 0%, #000 100%);
  z-index: 9999;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.5s ease, visibility 0.5s;
}

.start-screen.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.start-content {
  background: var(--bg-card);
  padding: 40px;
  border-radius: 12px;
  box-shadow: 0 0 50px rgba(0, 0, 0, 0.7);
  border: 1px solid var(--accent-gold);
  text-align: center;
  max-width: 500px;
  width: 90%;
  animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideUp {
  from {
    transform: translateY(50px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.game-title {
  font-size: 2.5rem;
  color: var(--accent-gold);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.subtitle {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-size: 1rem;
}

.control-group {
  margin-bottom: 1.5rem;
  text-align: left;
}

.control-group label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.control-group select {
  width: 100%;
  padding: 12px;
  background: #333;
  border: 1px solid #444;
  color: white;
  border-radius: 6px;
  font-size: 1rem;
}

.btn-start {
  width: 100%;
  padding: 15px;
  background: var(--accent-gold);
  color: #000;
  font-weight: 700;
  font-size: 1.2rem;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.2s, background 0.2s;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.btn-start:hover {
  background: #f1c40f;
  transform: translateY(-2px);
}

.btn-secondary {
  width: 100%;
  padding: 15px;
  background: #444;
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid #555;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
  margin-top: 10px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.btn-secondary:hover {
  background: #555;
  transform: translateY(-2px);
}

.footer-credits {
  margin-top: 2rem;
  font-size: 0.8rem;
  color: #555;
}

/* --- Main Game Container --- */
.container {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
  padding: 20px;
  width: 100%;
  max-width: 1600px;
  margin: 0 auto;
  transition: filter 0.5s ease;
}

.card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--border-color);
}

/* Board Area */
.board-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

.info-bar {
  width: 100%;
  display: flex;
  justify-content: space-between;
  margin-bottom: 15px;
  padding: 10px 15px;
  background: var(--bg-panel);
  border-radius: 8px;
  border-left: 4px solid var(--accent-gold);
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--text-primary);
}

.pulse {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--text-secondary); /* Default inactive */
  box-shadow: 0 0 8px rgba(255, 255, 255, 0.2);
}

#timer {
  font-family: monospace;
  font-size: 1.1rem;
  color: var(--accent-gold);
}

.board {
  display: grid;
  grid-template-columns: repeat(4, var(--square-size));
  grid-template-rows: repeat(5, var(--square-size));
  border: 8px solid #333;
  border-radius: 4px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.square {
  width: var(--square-size);
  height: var(--square-size);
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  cursor: pointer;
}

.light {
  background-color: var(--board-light);
}
.dark {
  background-color: var(--board-dark);
}

.square.selected {
  box-shadow: inset 0 0 0 4px var(--accent-gold);
}

.square.valid::after {
  content: "";
  width: 25%;
  height: 25%;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 50%;
}

.square.last-move {
  background-color: rgba(212, 175, 55, 0.4) !important;
}

.piece {
  font-size: calc(var(--square-size) * 0.7);
  user-select: none;
  filter: drop-shadow(0 4px 2px rgba(0, 0, 0, 0.3));
  cursor: grab;
}

.coord {
  position: absolute;
  bottom: 2px;
  right: 2px;
  font-size: 10px;
  color: rgba(0, 0, 0, 0.3);
  font-weight: bold;
}

/* --- Side Panels (Settings & History) --- */
.side-panel {
  width: 300px;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  transition: width 0.3s ease, transform 0.3s ease;
}

.collapsible-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 10px;
  cursor: pointer;
  color: var(--accent-gold);
  font-weight: 600;
}

.collapsible-content {
  overflow-y: auto;
  flex: 1;
}

/* Stats Area in History */
.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 15px;
}

.stat-box {
  background: var(--bg-panel);
  padding: 10px;
  border-radius: 6px;
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--text-primary);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.captured {
  margin-bottom: 15px;
}

.captured h3 {
  font-size: 0.9rem;
  margin-bottom: 5px;
  color: var(--text-secondary);
}

.captured-pieces {
  min-height: 30px;
  background: var(--bg-panel);
  border-radius: 4px;
  padding: 5px;
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.move-list {
  max-height: 200px;
  overflow-y: auto;
  background: var(--bg-panel);
  border-radius: 4px;
  padding: 5px;
}

.move-item {
  padding: 4px 8px;
  font-size: 0.9rem;
  border-bottom: 1px solid #333;
  display: flex;
  justify-content: space-between;
}
.move-item:last-child {
  border-bottom: none;
}
.move-number {
  color: var(--accent-gold);
  font-weight: bold;
  margin-right: 5px;
}

/* Buttons in Panel */
.controls button {
  width: 100%;
  margin-bottom: 10px;
  padding: 10px;
  border-radius: 6px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  background: #333;
  color: white;
  transition: background 0.2s;
}

.controls button:hover {
  background: #444;
}
.controls #btnNewGame {
  background: var(--accent-blue);
  color: white;
}
.controls #btnNewGame:hover {
  background: #4a70c0;
}
.controls #btnUndo {
  background: var(--accent-red);
  color: white;
}

/* --- Mobile / Responsive --- */
.mobile-menu-btn {
  position: fixed;
  top: 15px;
  left: 15px;
  z-index: 200;
  background: var(--bg-card);
  border: 1px solid var(--accent-gold);
  color: var(--accent-gold);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-size: 1.2rem;
  cursor: pointer;
  display: none; /* Hidden on large screens */
  justify-content: center;
  align-items: center;
}

.close-settings-btn {
  display: none;
}

/* Footer */
.copyright-footer {
  position: fixed;
  bottom: 0;
  width: 100%;
  background: rgba(18, 18, 18, 0.9);
  padding: 5px 20px;
  border-top: 1px solid #333;
  font-size: 0.8rem;
  display: flex;
  justify-content: center;
  z-index: 100;
}
.footer-content-copy {
  display: flex;
  gap: 20px;
  color: var(--text-secondary);
}
.highlight {
  color: var(--accent-gold);
}
.footer-icons {
  display: none;
} /* Hide icons to save space */

/* --- Media Queries for Layout --- */

/* Tablet / Iframe Mode (< 1200px) */
@media (max-width: 1200px) {
  .container {
    flex-wrap: wrap;
    align-items: flex-start;
    padding-top: 60px; /* Space for mobile menu btn */
  }

  /* Hide panels by default on smaller screens, use toggles */
  #settingsPanel {
    display: none; /* Toggled via JS/CSS class */
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 300;
    margin: 0;
    max-height: none;
    border-radius: 0;
    justify-content: center;
  }

  #settingsPanel.active {
    display: flex;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .close-settings-btn {
    display: block;
    position: absolute;
    top: 20px;
    right: 20px;
    background: transparent;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
  }

  /* Arrange Board and History side-by-side if possible */
  .board-card {
    order: 1;
  }

  #historyPanel {
    order: 2;
    width: 100%;
    max-width: 400px;
    margin-top: 0;
  }
}

/* Small Heights (Landscape Mobile or Small Iframe) */
@media (max-height: 650px) {
  :root {
    --square-size: 15vh; /* Maximize board */
  }
  .container {
    padding: 10px;
    gap: 10px;
    align-items: center;
  }
  .copyright-footer {
    display: none; /* Hide footer to save space */
  }
  .board-card {
    padding: 10px;
  }
  .info-bar {
    padding: 5px 10px;
    margin-bottom: 5px;
  }
  /* Move history to right of board if width allows, else stack */
  @media (min-width: 800px) {
    .container {
      flex-direction: row;
      align-items: center;
    }
    #historyPanel {
      height: 80vh; /* Match board height approx */
      width: 250px;
    }
  }
}