:root {
    --primary: #4a6fa5;
    --primary-dark: #3a5a8a;
    --success: #28a745;
    --danger: #dc3545;
    --warning: #ffc107;
    --info: #17a2b8;
    --light: #f8f9fa;
    --dark: #343a40;
    --card-bg: #ffffff;
    --shadow: 0 8px 25px rgba(0,0,0,0.15);
    --disabled: #e9ecef;
    --disabled-text: #6c757d;
    --border: #dee2e6;
    --text: #212529;
    --text-secondary: #6c757d;
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

[data-theme="dark"] {
    --primary: #5a8ee6;
    --primary-dark: #4a7dd6;
    --card-bg: #2d3748;
    --light: #1a202c;
    --dark: #e2e8f0;
    --border: #4a5568;
    --text: #e2e8f0;
    --text-secondary: #a0aec0;
    --bg-gradient: linear-gradient(135deg, #1a202c 0%, #2d3748 100%);
    --shadow: 0 8px 25px rgba(0,0,0,0.4);
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
    color: var(--text);
    transition: background 0.5s, color 0.5s;
}

.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    opacity: 0.3;
}

.particle {
    position: absolute;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    animation: float 15s infinite linear;
}

@keyframes float {
    0% { transform: translateY(0) translateX(0) rotate(0deg); opacity: 0; }
    10% { opacity: 0.5; }
    90% { opacity: 0.3; }
    100% { transform: translateY(-100vh) translateX(100px) rotate(360deg); opacity: 0; }
}

.top-toolbar {
    position: fixed;
    top: 15px;
    right: 15px;
    display: flex;
    gap: 10px;
    z-index: 10;
}

.tool-btn {
    background: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 14px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.tool-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.card {
    background: var(--card-bg);
    width: 90%;
    max-width: 680px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    padding: 30px;
    text-align: center;
    transition: all 0.3s ease;
    position: relative;
    z-index: 2;
    max-height: 85vh;
    overflow-y: auto;
    border: 1px solid var(--border);
    margin-bottom: 15px;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(0,0,0,0.2);
}

header h1 {
    margin: 0 0 10px 0;
    color: var(--primary);
    font-size: 28px;
    position: relative;
    display: inline-block;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--primary);
    border-radius: 3px;
}

header p {
    margin: 0 0 20px 0;
    color: var(--text-secondary);
    font-size: 16px;
}

.challenge-info {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 15px;
    display: none;
    animation: slideIn 0.5s;
}

.challenge-info.active {
    display: block;
}

.challenge-info h3 {
    margin: 0 0 10px 0;
    font-size: 18px;
}

.challenge-info p {
    margin: 5px 0;
    font-size: 14px;
    opacity: 0.9;
}

.status-bar {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin: 15px 0;
    padding: 12px 15px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    border: 1px solid transparent;
}

.status-bar.ready {
    background: rgba(23, 162, 184, 0.1);
    color: var(--info);
    border-color: var(--info);
}

.status-bar.playing {
    background: rgba(40, 167, 69, 0.1);
    color: var(--success);
    border-color: var(--success);
    animation: pulse 1.5s infinite;
}

.status-bar.ended {
    background: rgba(108, 117, 125, 0.1);
    color: var(--text-secondary);
    border-color: var(--border);
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.difficulty-selector {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.difficulty-btn {
    padding: 10px 18px;
    border: 2px solid var(--primary);
    background: var(--card-bg);
    color: var(--primary);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
    position: relative;
    overflow: hidden;
    font-size: 13px;
}

.difficulty-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(74, 111, 165, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.4s, height 0.4s;
}

.difficulty-btn:active::before {
    width: 200px;
    height: 200px;
}

.difficulty-btn:hover:not(:disabled) {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
}

.difficulty-btn.active {
    background: var(--primary);
    color: white;
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(74, 111, 165, 0.3);
}

.difficulty-btn:disabled {
    background: var(--disabled);
    color: var(--disabled-text);
    border-color: var(--border);
    cursor: not-allowed;
    transform: none;
}

.difficulty-btn.special {
    border-color: #667eea;
    color: #667eea;
}

.difficulty-btn.special:hover:not(:disabled) {
    background: #667eea;
    color: white;
}

.difficulty-btn.special.active {
    background: #667eea;
    color: white;
}

.difficulty-btn.danger {
    border-color: var(--danger);
    color: var(--danger);
}

.difficulty-btn.danger:hover:not(:disabled) {
    background: var(--danger);
    color: white;
}

.difficulty-btn.danger.active {
    background: var(--danger);
    color: white;
}

.game-status {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 10px;
    margin: 15px 0;
    padding: 10px;
    background: var(--light);
    border-radius: 8px;
    font-size: 14px;
    color: var(--text);
}

.status-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    padding: 8px;
    background: var(--card-bg);
    border-radius: 6px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    border: 1px solid var(--border);
}

.status-value {
    font-weight: bold;
    font-size: 18px;
    color: var(--primary);
}

.timer {
    color: var(--danger);
    font-weight: bold;
    animation: pulse 1s infinite;
}

.timer.safe {
    color: var(--success);
    animation: none;
}

.input-group {
    display: flex;
    gap: 10px;
    margin: 20px 0;
    position: relative;
}

#guessInput {
    flex: 1;
    padding: 14px 16px;
    font-size: 18px;
    border: 2px solid var(--border);
    border-radius: 8px;
    outline: none;
    transition: all 0.3s;
    background: var(--card-bg);
    color: var(--text);
}

#guessInput:focus {
    border-color: var(--primary);
    transform: scale(1.02);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.2);
}

#guessInput.shake {
    animation: shake 0.5s;
    border-color: var(--danger);
}

#guessInput:disabled {
    background: var(--disabled);
    cursor: not-allowed;
    transform: none;
    color: var(--disabled-text);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

#submitBtn {
    padding: 14px 24px;
    font-size: 16px;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

#submitBtn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255,255,255,0.3);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

#submitBtn:active:not(:disabled)::before {
    width: 300px;
    height: 300px;
}

#submitBtn:hover:not(:disabled) {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 111, 165, 0.4);
}

#submitBtn:disabled {
    background-color: var(--disabled);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
    color: var(--disabled-text);
}

.message {
    min-height: 40px;
    margin: 15px 0;
    font-size: 18px;
    font-weight: bold;
    color: var(--text);
    padding: 12px;
    border-radius: 8px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
    border-left: 4px solid transparent;
    background: var(--card-bg);
    border: 1px solid var(--border);
}

.message.success {
    color: white;
    background: var(--success);
    border-left-color: #1e7e34;
    animation: celebrate 0.8s;
}

.message.too-high {
    color: var(--danger);
    background: rgba(220, 53, 69, 0.1);
    border-left-color: var(--danger);
}

.message.too-low {
    color: var(--info);
    background: rgba(23, 162, 184, 0.1);
    border-left-color: var(--info);
}

.message.info {
    color: var(--text);
    background: var(--light);
    border-left-color: var(--warning);
}

.message.hint {
    color: var(--primary);
    background: rgba(74, 111, 165, 0.1);
    border-left-color: var(--primary);
    font-size: 16px;
    font-weight: normal;
}

@keyframes celebrate {
    0% { transform: scale(0.8); opacity: 0; }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.btn {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
    position: relative;
    overflow: hidden;
    background: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text);
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(0,0,0,0.1);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn:disabled {
    background-color: var(--disabled);
    color: var(--disabled-text);
    cursor: not-allowed;
    transform: none !important;
}

.btn-restart {
    background-color: var(--success);
    color: white;
    border: none;
}

.btn-restart:hover:not(:disabled) {
    background-color: #218838;
}

.btn-history {
    background-color: var(--info);
    color: white;
    border: none;
}

.btn-history:hover:not(:disabled) {
    background-color: #138496;
}

.btn-challenge {
    background-color: #667eea;
    color: white;
    border: none;
}

.btn-challenge:hover:not(:disabled) {
    background-color: #5a6fd8;
}

.collapsible-section {
    margin-top: 15px;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.3s;
    max-height: 0;
    opacity: 0;
}

.collapsible-section.show {
    max-height: 800px;
    opacity: 1;
    margin-top: 15px;
}

.collapsible-header {
    background: var(--light);
    padding: 12px 15px;
    cursor: pointer;
    font-weight: 600;
    color: var(--text);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s;
}

.collapsible-header:hover {
    background: var(--border);
}

.collapsible-content {
    padding: 15px;
    background: var(--card-bg);
    text-align: left;
    max-height: 500px;
    overflow-y: auto;
}

.history-list {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 200px;
    overflow-y: auto;
}

.history-item {
    padding: 10px;
    margin-bottom: 8px;
    background: var(--card-bg);
    border-radius: 6px;
    font-size: 13px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    animation: slideIn 0.3s;
    border-left: 4px solid transparent;
    border: 1px solid var(--border);
}

@keyframes slideIn {
    from { transform: translateX(-20px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

.history-item.win {
    border-left-color: var(--success);
    background: linear-gradient(to right, var(--card-bg), rgba(40, 167, 69, 0.1));
}

.history-item.lose {
    border-left-color: var(--danger);
    background: linear-gradient(to right, var(--card-bg), rgba(220, 53, 69, 0.1));
}

.history-item div {
    display: flex;
    gap: 12px;
    align-items: center;
}

.history-item span {
    font-weight: 600;
    color: var(--text);
}

.history-item .result {
    font-size: 16px;
}

.empty-history {
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
    padding: 15px;
    background: var(--card-bg);
    border-radius: 6px;
    border: 1px dashed var(--border);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}

.stat-card {
    background: var(--card-bg);
    padding: 12px;
    border-radius: 6px;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    border: 1px solid var(--border);
}

.stat-label {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.stat-value {
    font-size: 20px;
    font-weight: bold;
    color: var(--primary);
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
}

.achievement {
    background: var(--card-bg);
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    border: 2px solid var(--border);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.achievement.unlocked {
    border-color: var(--success);
    background: linear-gradient(135deg, var(--card-bg) 0%, rgba(40, 167, 69, 0.1) 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.2);
}

.achievement.unlocked::after {
    content: '✓';
    position: absolute;
    top: 5px;
    right: 8px;
    color: var(--success);
    font-weight: bold;
    font-size: 18px;
}

.achievement-icon {
    font-size: 24px;
    margin-bottom: 5px;
}

.achievement-name {
    font-size: 12px;
    font-weight: bold;
    color: var(--text);
    margin-bottom: 3px;
}

.achievement-desc {
    font-size: 10px;
    color: var(--text-secondary);
}

.achievement.locked {
    opacity: 0.5;
    filter: grayscale(100%);
}

.settings-grid {
    display: grid;
    gap: 12px;
}

.setting-item {
    background: var(--card-bg);
    padding: 12px;
    border-radius: 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border);
}

.setting-label {
    font-weight: 600;
    color: var(--text);
}

.toggle-switch {
    position: relative;
    width: 50px;
    height: 26px;
    background: #ccc;
    border-radius: 13px;
    cursor: pointer;
    transition: background 0.3s;
}

.toggle-switch.active {
    background: var(--success);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: transform 0.3s;
}

.toggle-switch.active::after {
    transform: translateX(24px);
}

.challenge-controls {
    display: flex;
    gap: 10px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.challenge-controls .btn {
    flex: 1;
    min-width: 120px;
}

.data-actions {
    display: flex;
    gap: 10px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.data-actions .btn {
    flex: 1;
    min-width: 140px;
}

textarea {
    width: 100%;
    min-height: 80px;
    margin-top: 10px;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--card-bg);
    color: var(--text);
    font-family: monospace;
    font-size: 12px;
    resize: vertical;
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
    margin-top: 10px;
}

.shortcut-item {
    background: var(--card-bg);
    padding: 10px;
    border-radius: 6px;
    border: 1px solid var(--border);
    font-size: 13px;
}

.shortcut-key {
    background: var(--light);
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: bold;
    color: var(--primary);
    font-family: monospace;
    margin-right: 8px;
}

.celebration {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 10;
    display: none;
}

.celebration.show {
    display: block;
    animation: fadeOut 2s forwards;
}

@keyframes fadeOut {
    0% { opacity: 1; }
    100% { opacity: 0; }
}

.confetti {
    position: absolute;
    width: 10px;
    height: 10px;
    background: #f00;
    animation: confetti-fall 3s linear forwards;
    opacity: 0;
}

@keyframes confetti-fall {
    0% {
        transform: translateY(-100vh) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) rotate(720deg);
        opacity: 0;
    }
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
    backdrop-filter: blur(3px);
}

.modal.show {
    opacity: 1;
    pointer-events: all;
}

.modal-content {
    background: var(--card-bg);
    padding: 35px;
    border-radius: 16px;
    width: 90%;
    max-width: 450px;
    text-align: center;
    transform: translateY(20px);
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
    border: 1px solid var(--border);
    color: var(--text);
}

.modal.show .modal-content {
    transform: translateY(0);
    box-shadow: 0 20px 50px rgba(0,0,0,0.4);
}

.modal-title {
    font-size: 26px;
    margin-bottom: 15px;
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.modal-message {
    font-size: 18px;
    margin-bottom: 25px;
    color: var(--text);
    line-height: 1.6;
}

.modal-achievements {
    margin: 15px 0;
    padding: 10px;
    background: var(--light);
    border-radius: 8px;
    display: none;
}

.modal-achievements.show {
    display: block;
}

.modal-achievements-title {
    font-size: 14px;
    font-weight: bold;
    margin-bottom: 8px;
    color: var(--success);
}

.modal-achievements-list {
    font-size: 13px;
    color: var(--text);
    text-align: left;
}

.modal-btn {
    padding: 12px 25px;
    font-size: 16px;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
    margin: 5px;
}

.modal-btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 111, 165, 0.4);
}

.modal-btn.secondary {
    background-color: var(--disabled);
    color: var(--text);
}

.modal-btn.secondary:hover {
    background-color: #d1d5db;
}

.notification {
    position: fixed;
    top: 80px;
    right: 20px;
    background: var(--card-bg);
    color: var(--text);
    padding: 12px 20px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    border-left: 4px solid var(--success);
    z-index: 1000;
    transform: translateX(400px);
    transition: transform 0.3s;
    max-width: 300px;
    border: 1px solid var(--border);
}

.notification.show {
    transform: translateX(0);
}

.notification.error {
    border-left-color: var(--danger);
}

.notification.info {
    border-left-color: var(--info);
}

@media (max-width: 700px) {
    .card {
        padding: 20px;
        max-width: 95%;
        max-height: 80vh;
    }

    .top-toolbar {
        top: 10px;
        right: 10px;
        gap: 5px;
    }

    .tool-btn {
        padding: 6px 10px;
        font-size: 12px;
    }

    .input-group {
        flex-direction: column;
    }

    #submitBtn {
        width: 100%;
    }

    .button-group {
        flex-direction: column;
        gap: 10px;
    }

    .btn {
        width: 100%;
    }

    .difficulty-selector {
        gap: 5px;
    }

    .difficulty-btn {
        padding: 8px 12px;
        font-size: 12px;
    }

    .game-status {
        grid-template-columns: repeat(3, 1fr);
    }

    .status-item {
        padding: 6px;
    }

    .status-value {
        font-size: 16px;
    }

    .achievements-grid,
    .stats-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }

    .shortcuts-grid {
        grid-template-columns: 1fr;
    }
}

.rules-content ul {
    margin: 10px 0 0 20px;
    padding: 0;
    color: var(--text);
    line-height: 1.8;
}

.rules-content li {
    margin-bottom: 8px;
}

.rules-content strong {
    color: var(--primary);
}

.rules-content h4 {
    margin-top: 15px;
    margin-bottom: 8px;
    color: var(--primary);
}