:root {
    --primary-bg: #F5A9A9;
    --secondary-bg: #F8C4C4;
    --board-bg: #FFFFFF;
    --text-dark: #2D2D2D;
    --text-light: #FFFFFF;
    --accent-coral: #E88888;
    --accent-dark: #D47070;
    --line-color: #E8A0A0;
    --letter-used: #4CAF50;
    --btn-bg: #FFFFFF;
    --btn-border: #333333;
    --success-green: #4CAF50;
    --error-red: #E57373;
    --shadow: rgba(0, 0, 0, 0.1);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

html,
body {
    min-height: 100vh;
    /* 使用 !important 强制锁定背景，防止插件篡改 */
    background-color: var(--primary-bg) !important;
    background: linear-gradient(135deg, var(--primary-bg) 0%, var(--secondary-bg) 100%) no-repeat fixed !important;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
}

.header {
    text-align: center;
    padding: 2rem 1rem 1rem;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.unlimited-badge {
    display: inline-block;
    background: linear-gradient(135deg, #FFD700, #FFA500);
    color: #333;
    padding: 0.2rem 0.6rem;
    border-radius: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    vertical-align: middle;
    margin-left: 0.3rem;
}

.tagline {
    font-size: 1.1rem;
    color: var(--text-dark);
    opacity: 0.8;
}

.main-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
}

.game-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

/* Current word above the box */
.current-word-container {
    min-height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.5rem;
}

.current-word {
    font-size: 2rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--text-dark);
    text-transform: uppercase;
    min-height: 2.5rem;
}

/* Game board wrapper - provides space for letters outside the box */
.game-board-wrapper {
    padding: 50px;
    margin: 0;
}

.game-board-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.game-board {
    position: relative;
    width: 320px;
    height: 320px;
    background: var(--board-bg);
    border: 3px solid var(--text-dark);
    border-radius: 8px;
}

.lines-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.letter {
    position: absolute;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 2;
    transition: transform 0.15s ease;
}

.letter:hover {
    transform: scale(1.1);
}

.letter-circle {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #FFF;
    border: 2px solid var(--accent-coral);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

/* Active letter (currently being selected) - filled circle */
.letter.active .letter-circle {
    background: #333;
    border-color: #333;
}

/* Used letter (part of completed words) - green circle */
.letter.used .letter-circle {
    background: var(--letter-used);
    border-color: #388E3C;
}

.letter-text {
    position: absolute;
    font-size: 1.4rem;
    font-weight: 700;
    color: #FFF;
    pointer-events: none;
    user-select: none;
    transition: color 0.2s ease;
}

/* Active letter - black text on dark circle visible */
.letter.active .letter-text {
    color: #333;
}

/* Used letter (part of completed words) - black text */
.letter.used .letter-text {
    color: #333;
}

.letter[data-side="top"] {
    top: -20px;
}

.letter[data-side="top"][data-index="0"] {
    left: 60px;
}

.letter[data-side="top"][data-index="1"] {
    left: 140px;
}

.letter[data-side="top"][data-index="2"] {
    left: 220px;
}

.letter[data-side="top"] .letter-text {
    top: -28px;
}

.letter[data-side="right"] {
    right: -20px;
}

.letter[data-side="right"][data-index="0"] {
    top: 60px;
}

.letter[data-side="right"][data-index="1"] {
    top: 140px;
}

.letter[data-side="right"][data-index="2"] {
    top: 220px;
}

.letter[data-side="right"] .letter-text {
    right: -28px;
}

.letter[data-side="bottom"] {
    bottom: -20px;
}

.letter[data-side="bottom"][data-index="0"] {
    left: 60px;
}

.letter[data-side="bottom"][data-index="1"] {
    left: 140px;
}

.letter[data-side="bottom"][data-index="2"] {
    left: 220px;
}

.letter[data-side="bottom"] .letter-text {
    bottom: -28px;
}

.letter[data-side="left"] {
    left: -20px;
}

.letter[data-side="left"][data-index="0"] {
    top: 60px;
}

.letter[data-side="left"][data-index="1"] {
    top: 140px;
}

.letter[data-side="left"][data-index="2"] {
    top: 220px;
}

.letter[data-side="left"] .letter-text {
    left: -28px;
}

/* Stats section below the box */
.game-stats {
    width: 100%;
    max-width: 400px;
    margin-top: 1rem;
}

.stats-row {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
}

.stat-label {
    color: var(--text-dark);
    opacity: 0.8;
}

.stat-value {
    font-weight: 600;
    color: var(--text-dark);
}

.completed-words-container {
    min-height: 2rem;
    text-align: center;
    margin-top: 0.5rem;
}

.completed-words {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    align-items: center;
}

.completed-word {
    background: linear-gradient(to bottom, #43a047, #2E7D32);
    /* 更有质感的渐变绿 */
    color: white;
    padding: 0.5rem 1.4rem;
    border-radius: 20px;
    font-weight: 800;
    font-size: 1.1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.15);
    letter-spacing: 0.08em;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
    animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.word-connector {
    color: #444;
    font-weight: 900;
    font-size: 1.5rem;
    margin: 0 0.4rem;
    filter: drop-shadow(0 1px 1px white);
}

.controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1rem;
}

.btn {
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    padding: 0.8rem 1.8rem;
    border-radius: 2rem;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 2px solid var(--btn-border);
    background: var(--btn-bg);
    color: var(--text-dark);
}

.btn:hover {
    background: #F0F0F0;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.btn:active {
    transform: translateY(0);
}

.btn-enter {
    background: var(--text-dark);
    color: var(--text-light);
}

.btn-enter:hover {
    background: #444;
}

.new-puzzle-container {
    margin-top: 0.5rem;
}

.btn-new-puzzle {
    background: linear-gradient(135deg, #FFD700, #FFA500);
    border-color: #CC8400;
    color: #333;
    font-weight: 600;
}

.btn-new-puzzle:hover {
    background: linear-gradient(135deg, #FFE44D, #FFB833);
}

.message {
    min-height: 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    padding: 0.8rem 1.5rem;
    border-radius: 0.5rem;
    opacity: 0;
    transition: opacity 0.3s ease;
    margin-top: 0.5rem;
}

.message.show {
    opacity: 1;
}

.message.success {
    color: var(--success-green);
    background: rgba(76, 175, 80, 0.15);
    border: 2px solid var(--success-green);
}

.message.info {
    color: #1976D2;
    background: rgba(25, 118, 210, 0.1);
    border: 2px solid #1976D2;
}

.message.error {
    color: #c62828;
    background: rgba(229, 115, 115, 0.2);
    border: 2px solid var(--error-red);
    animation: shake 0.4s ease-in-out;
}

.message.win {
    font-size: 1.5rem;
    color: var(--success-green);
    background: rgba(76, 175, 80, 0.2);
    border: 2px solid var(--success-green);
    animation: pulse 0.5s ease-in-out;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    20%,
    60% {
        transform: translateX(-8px);
    }

    40%,
    80% {
        transform: translateX(8px);
    }
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

.faq-section {
    margin-top: 3rem;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 4px 20px var(--shadow);
}

.faq-section h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
    text-align: center;
}

.faq-item {
    margin-bottom: 1.5rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    padding-bottom: 1.5rem;
}

.faq-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}

.faq-item h3 {
    font-size: 1.2rem;
    color: var(--accent-dark);
    margin-bottom: 0.8rem;
}

.faq-item h4 {
    font-size: 1rem;
    color: var(--text-dark);
    margin: 1rem 0 0.5rem;
}

.faq-answer p {
    margin-bottom: 0.8rem;
}

.faq-answer ul {
    margin-left: 1.5rem;
    margin-bottom: 0.8rem;
}

.faq-answer li {
    margin-bottom: 0.4rem;
}

.footer {
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 2rem;
    color: var(--text-dark);
    opacity: 0.7;
    font-size: 0.9rem;
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.8rem;
    }

    .game-board-wrapper {
        padding: 40px;
    }

    .game-board {
        width: 280px;
        height: 280px;
    }

    .letter[data-side="top"][data-index="0"],
    .letter[data-side="bottom"][data-index="0"] {
        left: 50px;
    }

    .letter[data-side="top"][data-index="1"],
    .letter[data-side="bottom"][data-index="1"] {
        left: 120px;
    }

    .letter[data-side="top"][data-index="2"],
    .letter[data-side="bottom"][data-index="2"] {
        left: 190px;
    }

    .letter[data-side="right"][data-index="0"],
    .letter[data-side="left"][data-index="0"] {
        top: 50px;
    }

    .letter[data-side="right"][data-index="1"],
    .letter[data-side="left"][data-index="1"] {
        top: 120px;
    }

    .letter[data-side="right"][data-index="2"],
    .letter[data-side="left"][data-index="2"] {
        top: 190px;
    }

    .current-word {
        font-size: 1.5rem;
    }

    .controls {
        gap: 0.5rem;
    }

    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }

    .faq-section {
        padding: 1.5rem;
    }

    .stats-row {
        gap: 1rem;
    }
}

/* Lines for connecting letters */
#linesSvg line {
    stroke-linecap: round;
    transition: all 0.3s ease;
}

#linesSvg line.line-completed {
    stroke: var(--primary-bg);
    stroke-width: 3;
    opacity: 0.25;
    /* 历史单词：浅色半透明 */
}

#linesSvg line.line-active {
    stroke: var(--primary-bg);
    stroke-width: 5;
    opacity: 1;
    /* 当前单词：深色实线 */
    filter: drop-shadow(0 0 2px rgba(0, 0, 0, 0.1));
}

/* Current word being typed - dashed coral line */
.word-line.current {
    stroke: var(--accent-coral);
    stroke-width: 4;
    stroke-dasharray: 12, 6;
}

/* Completed word - solid coral line */
.word-line.completed {
    stroke: var(--accent-coral);
    stroke-width: 4;
    stroke-dasharray: none;
}

/* Previous completed words - lighter faded line */
.word-line.previous {
    stroke: var(--line-color);
    stroke-width: 3;
    stroke-dasharray: none;
    opacity: 0.6;
}