/* ==========================================
   設計系統與變數
   ========================================== */
:root {
    --bg-dark: #07080d;
    --panel-bg: rgba(13, 17, 28, 0.65);
    --panel-border: rgba(255, 255, 255, 0.08);
    --text-primary: #f0f2f5;
    --text-muted: #8a99ad;
    
    /* 霓虹色彩 */
    --color-cyan: #00f2fe;
    --color-blue: #007fff;
    --color-magenta: #f857a6;
    --color-purple: #7f00ff;
    --color-gold: #ffd700;
    --color-green: #39ff14;

    /* 漸變 */
    --gradient-primary: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
    --gradient-accent: linear-gradient(135deg, #f857a6 0%, #ff5858 100%);
    --gradient-dark: linear-gradient(180deg, #0f111a 0%, #07080d 100%);
    
    /* 字型 */
    --font-display: 'Outfit', 'Noto Sans TC', sans-serif;
}

/* ==========================================
   基礎設定與太空背景
   ========================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-dark);
    background-image: var(--gradient-dark);
    color: var(--text-primary);
    font-family: var(--font-display);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* 粒子星空背景 */
.stars-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(white, rgba(255,255,255,.2) 2px, transparent 40px),
        radial-gradient(white, rgba(255,255,255,.15) 1px, transparent 30px),
        radial-gradient(white, rgba(255,255,255,.1) 2px, transparent 40px);
    background-size: 550px 550px, 350px 350px, 250px 250px;
    background-position: 0 0, 40px 60px, 130px 270px;
    opacity: 0.25;
    z-index: 0;
    pointer-events: none;
}

/* 星雲發光效果 */
.nebula-effect {
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(127, 0, 255, 0.15) 0%, rgba(0, 242, 254, 0.05) 50%, transparent 70%);
    z-index: 0;
    pointer-events: none;
    filter: blur(50px);
    animation: rotateNebula 40s linear infinite;
}

@keyframes rotateNebula {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}

/* ==========================================
   共用組件：毛玻璃與按鈕
   ========================================== */
.glass-panel {
    background: var(--panel-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

.btn {
    font-family: var(--font-display);
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.25, 0.8, 0.25, 1);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 25px rgba(0, 242, 254, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.btn-icon-only {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 1.1rem;
}

.btn-icon-only:hover {
    background: var(--gradient-accent);
    color: #fff;
    transform: rotate(15deg) scale(1.05);
}

.btn-block {
    width: 100%;
    padding: 14px;
}

/* ==========================================
   版面架構 (App Container)
   ========================================== */
.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
    min-height: 100vh;
}

/* 頂部標題與數據列 */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 16px;
}

.logo-icon {
    font-size: 2.2rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 10px rgba(0, 242, 254, 0.4));
    animation: pulse 2s infinite ease-in-out;
}

@keyframes pulse {
    0%, 100% { filter: drop-shadow(0 0 5px rgba(0, 242, 254, 0.4)); }
    50% { filter: drop-shadow(0 0 15px rgba(0, 242, 254, 0.8)); }
}

.title-group h1 {
    font-size: 1.5rem;
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: 0.5px;
}

.title-group h1 span {
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--color-cyan);
    margin-left: 10px;
    background: rgba(0, 242, 254, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid rgba(0, 242, 254, 0.2);
}

.subtitle {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.quick-stats {
    display: flex;
    gap: 20px;
}

.stat-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(0, 0, 0, 0.2);
    padding: 8px 16px;
    border-radius: 10px;
    border-left: 3px solid var(--color-cyan);
    min-width: 100px;
}

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

.stat-value {
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--color-cyan);
}

.header-actions {
    display: flex;
    gap: 12px;
}

.header-actions .btn {
    padding: 10px 18px;
    font-size: 0.9rem;
}

/* ==========================================
   主遊戲佈局 (Game Layout)
   ========================================== */
.game-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 20px;
    align-items: start;
    flex-grow: 1;
}

/* 側邊設定面板 */
.settings-sidebar {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.settings-sidebar h2 {
    font-size: 1.2rem;
    font-weight: 700;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 12px;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group label {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
    display: flex;
    justify-content: space-between;
}

.control-group label span {
    color: var(--color-cyan);
    font-weight: 800;
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
    transition: background 0.3s;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-cyan);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(0, 242, 254, 0.5);
    transition: transform 0.1s, background-color 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background-color: #fff;
}

.target-selector {
    background: rgba(255, 255, 255, 0.03);
    padding: 12px;
    border-radius: 8px;
    border: 1px dashed rgba(255, 255, 255, 0.1);
}

.target-info {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.4;
}

.target-info span {
    color: var(--color-gold);
    font-weight: 700;
}

/* ==========================================
   棋盤展示區 (Board Area)
   ========================================== */
.board-area {
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: center;
    width: 100%;
}

.target-notification {
    background: rgba(255, 215, 0, 0.08);
    border: 1px solid rgba(255, 215, 0, 0.25);
    color: #ffe066;
    padding: 10px 24px;
    border-radius: 30px;
    font-size: 0.9rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    animation: floatTip 3s infinite ease-in-out;
}

@keyframes floatTip {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-4px); }
}

.board-wrapper {
    width: 100%;
    background: rgba(5, 7, 12, 0.6);
    border: 1px solid var(--panel-border);
    border-radius: 20px;
    padding: 25px;
    box-shadow: inset 0 4px 20px rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
    position: relative;
    overflow: auto;
}

/* 動態網格棋盤 */
.game-board {
    display: grid;
    gap: 12px;
    background: rgba(255,255,255,0.02);
    padding: 12px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.05);
    user-select: none;
}

/* 棋盤格 */
.board-cell {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    position: relative;
    aspect-ratio: 1 / 1;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: center;
    padding-bottom: 10px;
    cursor: pointer;
    box-shadow: inset 0 2px 8px rgba(0,0,0,0.4);
    transition: all 0.25s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* 二分圖棋盤格：黑白相間樣式 */
.board-cell.cell-dark {
    background: rgba(0, 0, 0, 0.25);
}
.board-cell.cell-light {
    background: rgba(255, 255, 255, 0.05);
}

.board-cell:hover {
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.1);
}

/* 目標格多色樣式 */
.board-cell.cell-target-g1 {
    border: 2px solid var(--color-magenta);
    background: radial-gradient(circle, rgba(248, 87, 166, 0.12) 0%, rgba(248, 87, 166, 0.02) 80%);
    box-shadow: 0 0 20px rgba(248, 87, 166, 0.2);
}
.board-cell.cell-target-g1::before {
    content: '▲ 紅塔目標';
    position: absolute;
    top: 4px;
    font-size: 0.65rem;
    font-weight: 800;
    color: var(--color-magenta);
    letter-spacing: 0.5px;
    opacity: 0.8;
}

.board-cell.cell-target-g2 {
    border: 2px solid var(--color-cyan);
    background: radial-gradient(circle, rgba(0, 242, 254, 0.12) 0%, rgba(0, 242, 254, 0.02) 80%);
    box-shadow: 0 0 20px rgba(0, 242, 254, 0.2);
}
.board-cell.cell-target-g2::before {
    content: '▲ 藍塔目標';
    position: absolute;
    top: 4px;
    font-size: 0.65rem;
    font-weight: 800;
    color: var(--color-cyan);
    letter-spacing: 0.5px;
    opacity: 0.8;
}

.board-cell.cell-target-g3 {
    border: 2px solid var(--color-green);
    background: radial-gradient(circle, rgba(57, 255, 20, 0.12) 0%, rgba(57, 255, 20, 0.02) 80%);
    box-shadow: 0 0 20px rgba(57, 255, 20, 0.2);
}
.board-cell.cell-target-g3::before {
    content: '▲ 綠塔目標';
    position: absolute;
    top: 4px;
    font-size: 0.65rem;
    font-weight: 800;
    color: var(--color-green);
    letter-spacing: 0.5px;
    opacity: 0.8;
}

/* 被選取的格/盤子 */
.board-cell.selected {
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.4);
    border-color: var(--color-cyan);
    background: rgba(0, 242, 254, 0.05) !important;
}

/* 可行目標格 */
.board-cell.highlight-valid {
    border: 2px dashed var(--color-green);
    background: rgba(57, 255, 20, 0.04) !important;
    animation: borderPulse 1.5s infinite alternate;
}

@keyframes borderPulse {
    from { box-shadow: 0 0 4px rgba(57, 255, 20, 0.2); }
    to { box-shadow: 0 0 15px rgba(57, 255, 20, 0.5); }
}

/* 棋盤格座標標籤 */
.cell-coord {
    position: absolute;
    top: 4px;
    left: 6px;
    font-size: 0.65rem;
    color: var(--text-muted);
    opacity: 0.4;
    font-weight: 600;
}

/* ==========================================
   河內塔圓盤 (Hanoi Disks)
   ========================================== */
.disk-peg-visual {
    position: absolute;
    bottom: 0;
    width: 6px;
    height: 70%;
    background: rgba(255,255,255,0.08);
    border-radius: 3px 3px 0 0;
    z-index: 1;
    pointer-events: none;
}

.disk {
    height: 14px;
    border-radius: 7px;
    z-index: 2;
    position: absolute;
    bottom: calc(var(--stack-index) * 16px + 8px);
    transition: all 0.3s cubic-bezier(0.25, 1, 0.5, 1);
    box-shadow: 0 3px 6px rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.65rem;
    font-weight: 800;
    color: #fff;
    text-shadow: 0 1px 2px rgba(0,0,0,0.8);
    pointer-events: none;
    border: 1px solid rgba(255, 255, 255, 0.15);
}

/* 用於棋盤的圓盤寬度自適應 (支援 3~6 層塔) */
.disk-size-1 { width: 35%; }
.disk-size-2 { width: 47%; }
.disk-size-3 { width: 59%; }
.disk-size-4 { width: 71%; }
.disk-size-5 { width: 83%; }
.disk-size-6 { width: 95%; }

/* 圓盤多塔顏色樣式 */
.disk.disk-g1 {
    background: linear-gradient(90deg, #ff0844 0%, #ffb199 100%);
    box-shadow: 0 0 10px rgba(255,8,68,0.4);
}
.disk.disk-g2 {
    background: linear-gradient(90deg, #00c6ff 0%, #0072ff 100%);
    box-shadow: 0 0 10px rgba(0,198,255,0.4);
}
.disk.disk-g3 {
    background: linear-gradient(90deg, #11998e 0%, #38ef7d 100%);
    box-shadow: 0 0 10px rgba(56,239,125,0.4);
}

/* 目標通知欄多塔標籤樣式 */
.targets-container {
    display: inline-flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 5px;
    vertical-align: middle;
}
.target-badge {
    padding: 3px 12px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.8rem;
    display: inline-flex;
    align-items: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}
.target-badge-g1 {
    background: rgba(248, 87, 166, 0.15);
    color: #ff69b4;
    border: 1px solid rgba(248, 87, 166, 0.3);
}
.target-badge-g2 {
    background: rgba(0, 242, 254, 0.15);
    color: var(--color-cyan);
    border: 1px solid rgba(0, 242, 254, 0.3);
}
.target-badge-g3 {
    background: rgba(57, 255, 20, 0.15);
    color: var(--color-green);
    border: 1px solid rgba(57, 255, 20, 0.3);
}

/* 如果被選取，圓盤發光特效 */
.board-cell.selected .disk:last-child {
    transform: scale(1.08) translateY(-4px);
    box-shadow: 0 8px 20px rgba(255,255,255,0.6);
    border-color: #fff;
    filter: brightness(1.2);
    z-index: 10;
}

/* ==========================================
   彈窗 (Modals)
   ========================================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(3, 4, 8, 0.85);
    z-index: 100;
    align-items: center;
    justify-content: center;
    padding: 20px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.show {
    display: flex;
    opacity: 1;
}

.modal-content {
    width: 100%;
    max-width: 550px;
    padding: 32px;
    position: relative;
    transform: translateY(-20px);
    transition: transform 0.3s ease;
}

.modal.show .modal-content {
    transform: translateY(0);
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 24px;
    font-size: 2rem;
    color: var(--text-muted);
    cursor: pointer;
    line-height: 1;
    transition: color 0.2s;
}

.modal-close:hover {
    color: #fff;
}

.modal h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.modal-body {
    font-size: 0.95rem;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.modal-body h3 {
    font-size: 1.1rem;
    color: var(--color-cyan);
    margin-top: 10px;
}

.modal-body ol {
    padding-left: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.rule-visual {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 15px;
}

.visual-example {
    background: rgba(0,0,0,0.3);
    padding: 12px;
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.05);
}

.visual-example p {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 8px;
}

.badge {
    font-size: 0.7rem;
    padding: 3px 8px;
    border-radius: 4px;
    font-weight: 800;
    display: inline-block;
}

.badge-normal {
    background: rgba(0, 127, 255, 0.2);
    color: var(--color-blue);
    border: 1px solid rgba(0, 127, 255, 0.4);
}

.badge-jump {
    background: rgba(57, 255, 20, 0.2);
    color: var(--color-green);
    border: 1px solid rgba(57, 255, 20, 0.4);
}

.modal-footer {
    margin-top: 24px;
    text-align: right;
}

/* 勝利彈窗特化 */
.victory-content {
    text-align: center;
    border-color: rgba(255, 215, 0, 0.3);
    box-shadow: 0 0 40px rgba(255, 215, 0, 0.15);
}

.victory-banner {
    font-size: 4rem;
    line-height: 1;
    margin-bottom: 15px;
    animation: trophyFloat 2s infinite ease-in-out;
}

@keyframes trophyFloat {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-8px) scale(1.05); }
}

.victory-content h2 {
    font-size: 2rem;
    background: linear-gradient(135deg, #ffe066 0%, #f5af19 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.victory-stats {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin: 24px 0;
}

.v-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.v-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.v-value {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--color-gold);
}

/* ==========================================
   響應式設計 (RWD)
   ========================================== */
@media (max-width: 900px) {
    .game-layout {
        grid-template-columns: 1fr;
    }
    .settings-sidebar {
        order: 2;
    }
    .board-area {
        order: 1;
    }
    .quick-stats {
        display: none;
    }
}