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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    text-align: center;
}

h1 {
    color: white;
    margin-bottom: 20px;
    font-size: 2.5em;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.mode-selector {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 15px 30px;
    border-radius: 15px;
    margin-bottom: 15px;
    display: inline-block;
}

.mode-selector label {
    color: white;
    font-size: 1.1em;
    font-weight: bold;
    margin-right: 10px;
}

.mode-selector select {
    padding: 8px 15px;
    font-size: 1em;
    border-radius: 8px;
    border: none;
    background: white;
    color: #667eea;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

.theme-selector {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 15px 30px;
    border-radius: 15px;
    margin-bottom: 15px;
    display: inline-block;
}

.theme-selector label {
    color: white;
    font-size: 1.1em;
    font-weight: bold;
    margin-right: 10px;
}

.theme-selector select {
    padding: 8px 15px;
    font-size: 1em;
    border-radius: 8px;
    border: none;
    background: white;
    color: #667eea;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

.size-selector {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 15px 30px;
    border-radius: 15px;
    margin-bottom: 15px;
    display: inline-block;
    margin-left: 10px;
}

.size-selector label {
    color: white;
    font-size: 1.1em;
    font-weight: bold;
    margin-right: 10px;
}

.size-selector select {
    padding: 8px 15px;
    font-size: 1em;
    border-radius: 8px;
    border: none;
    background: white;
    color: #667eea;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

.stats {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 15px 30px;
    border-radius: 15px;
    margin-bottom: 20px;
    display: inline-block;
}

.stats span {
    color: white;
    font-size: 1.2em;
    font-weight: bold;
    margin: 0 15px;
}

.turn-indicator {
    background: rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    padding: 10px 25px;
    border-radius: 10px;
    margin-bottom: 15px;
    display: inline-block;
    min-width: 180px;
}

.turn-indicator span {
    color: white;
    font-size: 1.1em;
    font-weight: bold;
}

.game-board {
    display: grid;
    gap: 10px;
    max-width: 600px;
    margin: 0 auto 20px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
}

.card {
    aspect-ratio: 1;
    background: white;
    border-radius: 10px;
    cursor: pointer;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.3s ease;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.card:hover {
    transform: scale(1.05);
}

.card.flipped {
    transform: rotateY(180deg);
}

.card.matched {
    opacity: 0;
    pointer-events: none;
    transform: scale(0);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.card.disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    font-size: 3em;
}

.card-back {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.card-front {
    background: white;
    transform: rotateY(180deg);
}

.restart-btn {
    background: white;
    color: #667eea;
    border: none;
    padding: 15px 40px;
    font-size: 1.2em;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    margin: 5px;
}

.restart-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

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

.modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: 40px 60px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.3);
    text-align: center;
    display: none;
    z-index: 1000;
    max-width: 90%;
}

.modal.show {
    display: block;
    animation: popup 0.5s ease;
}

@keyframes popup {
    0% {
        transform: translate(-50%, -50%) scale(0);
    }
    100% {
        transform: translate(-50%, -50%) scale(1);
    }
}

.modal h2 {
    color: #667eea;
    font-size: 2.5em;
    margin-bottom: 20px;
}

.modal p {
    color: #666;
    font-size: 1.3em;
    margin-bottom: 10px;
}

.modal input {
    padding: 12px 20px;
    font-size: 1.1em;
    border: 2px solid #667eea;
    border-radius: 10px;
    margin: 10px 0;
    width: 100%;
    max-width: 300px;
    text-align: center;
    text-transform: uppercase;
}

.room-code {
    background: #f0f0f0;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    font-family: monospace;
    font-size: 2em;
    color: #667eea;
    font-weight: bold;
    letter-spacing: 3px;
}

.score-text {
    background: #f0f0f0;
    padding: 15px;
    border-radius: 10px;
    margin: 20px 0;
    font-family: monospace;
    font-size: 1em;
    color: #333;
    white-space: pre-line;
    text-align: left;
}

.button-group {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 20px;
    flex-wrap: wrap;
}

.copy-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 30px;
    font-size: 1em;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
}

.copy-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

.copy-btn.copied {
    background: #4CAF50;
}

/* === In-Game Chat (Vs Friend) === */
.chat-toggle {
    position: fixed;
    bottom: 18px;
    right: 20px;
    background: #333;
    color: #fff;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.4);
    transition: transform 0.2s ease, background 0.3s ease;
    z-index: 50;
}
.chat-toggle:hover { background: #444; transform: scale(1.05); }
.chat-toggle.notify::after {
    content: "";
    position: absolute;
    top: 8px;
    right: 8px;
    width: 10px;
    height: 10px;
    background: #e74c3c;
    border-radius: 50%;
}
.chat-window {
    position: fixed;
    bottom: 70px;
    right: 20px;
    width: 260px;
    max-height: 330px;
    display: flex;
    flex-direction: column;
    background: #222;
    border-radius: 10px;
    box-shadow: 0 0 8px rgba(0,0,0,0.5);
    overflow: hidden;
    z-index: 50;
}
.chat-window.hidden { display: none; }
#chat-header {
    background: #333;
    color: #fff;
    padding: 6px 10px;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.chat-close { cursor: pointer; opacity: 0.7; }
.chat-close:hover { opacity: 1; }
#chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
    font-size: 14px;
}
.message {
    margin-bottom: 4px;
    line-height: 1.3;
    word-wrap: break-word;
}
.message.me { text-align: right; color: #8ecaff; }
.message.them { text-align: left; color: #ccc; }
#chat-input-row {
    display: flex;
    border-top: 1px solid #444;
}
#chat-input {
    flex: 1;
    border: none;
    background: #111;
    color: #eee;
    padding: 6px;
    font-size: 14px;
}
#chat-send {
    background: #555;
    border: none;
    color: #fff;
    padding: 6px 10px;
    cursor: pointer;
}
#chat-send:hover { background: #666; }

.back-to-portfolio {
    position: fixed;
    top: 20px;
    left: 20px;
    background: rgba(255, 255, 255, 0.9);
    color: #667eea;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 0.9em;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-portfolio:hover {
    background: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

@media (max-width: 600px) {
    .game-board {
        gap: 5px;
        padding: 10px;
    }

    .card-face {
        font-size: 2em;
    }

    h1 {
        font-size: 2em;
    }

    .modal {
        padding: 30px 40px;
    }

    .modal h2 {
        font-size: 2em;
    }

    .modal p {
        font-size: 1.1em;
    }
}