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

body {
    font-family: 'Courier New', monospace;
    background: transparent;
    color: #e0e0e0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    overflow-x: hidden;
    position: relative;
}

/* Background matching website */
#bg {
    -moz-transform: scale(1.0);
    -webkit-transform: scale(1.0);
    -ms-transform: scale(1.0);
    transform: scale(1.0);
    -webkit-backface-visibility: hidden;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    z-index: 1;
}

#bg:before, #bg:after {
    content: '';
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

#bg:before {
    -moz-transition: background-color 2.5s ease-in-out;
    -webkit-transition: background-color 2.5s ease-in-out;
    -ms-transition: background-color 2.5s ease-in-out;
    transition: background-color 2.5s ease-in-out;
    -moz-transition-delay: 0.75s;
    -webkit-transition-delay: 0.75s;
    -ms-transition-delay: 0.75s;
    transition-delay: 0.75s;
    background-image: linear-gradient(to top, rgba(19, 21, 25, 0.5), rgba(19, 21, 25, 0.5)), url("../images/overlay.png");
    background-size: auto, 256px 256px;
    background-position: center, center;
    background-repeat: no-repeat, repeat;
    z-index: 2;
}

#bg:after {
    -moz-transform: scale(1.125);
    -webkit-transform: scale(1.125);
    -ms-transform: scale(1.125);
    transform: scale(1.125);
    -moz-transition: -moz-transform 0.325s ease-in-out, -moz-filter 0.325s ease-in-out;
    -webkit-transition: -webkit-transform 0.325s ease-in-out, -webkit-filter 0.325s ease-in-out;
    -ms-transition: -ms-transform 0.325s ease-in-out, -ms-filter 0.325s ease-in-out;
    transition: transform 0.325s ease-in-out, filter 0.325s ease-in-out;
    background-image: url("../images/bg.jpg");
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
    z-index: 1;
}

#app {
    width: 100%;
    max-width: 1200px;
    position: relative;
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.screen {
    width: 100%;
}

.hidden {
    display: none !important;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(2px);
}

/* ASCII Box Styling */
.ascii-box {
    background: rgba(19, 21, 25, 0.85);
    border: 2px solid rgba(255, 255, 255, 0.2);
    padding: 20px;
    text-align: center;
    backdrop-filter: blur(4px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
    position: relative;
}

/* Close button */
#start-screen .close-button {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    line-height: 32px;
    text-align: center;
    font-size: 2em;
    color: #ffffff;
    text-decoration: none;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 4px;
    background: rgba(19, 21, 25, 0.6);
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    backdrop-filter: blur(2px);
}

#start-screen .close-button:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
    color: #ff4444;
    transform: scale(1.1);
}

.ascii-box pre {
    margin: 0;
    color: #fff;
    font-size: 1.2em;
}

.title {
    font-size: 1.5em;
    margin-bottom: 20px;
}

.content {
    margin-top: 20px;
    line-height: 1.8;
}

.instructions {
    text-align: left;
    margin: 20px 0;
    padding: 15px;
    background: rgba(19, 21, 25, 0.6);
    border-left: 3px solid #4a9eff;
    backdrop-filter: blur(2px);
}

.high-score {
    margin: 20px 0;
    font-size: 1.2em;
    color: #ffd700;
}

.start-prompt, .restart-prompt {
    margin-top: 30px;
    font-size: 1.1em;
    color: #4a9eff;
}

#game-screen {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

/* Game Title */
.game-title {
    text-align: center;
    margin-bottom: 15px;
    width: 100%;
    max-width: 800px;
}

.game-title h1 {
    font-size: 2em;
    font-weight: bold;
    color: #fff;
    letter-spacing: 0.3em;
    margin: 0;
    text-shadow: 0 0 10px rgba(74, 158, 255, 0.5);
}

.game-title .subtitle {
    font-size: 0.9em;
    color: #888;
    margin-top: 5px;
    letter-spacing: 0.1em;
}

/* Game Screen */
.game-header {
    display: flex;
    justify-content: space-around;
    padding: 15px;
    background: rgba(19, 21, 25, 0.85);
    border: 2px solid rgba(255, 255, 255, 0.2);
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
    backdrop-filter: blur(4px);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 800px;
}

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.stat .label {
    font-size: 0.8em;
    color: #888;
}

.stat span:last-child {
    font-size: 1.3em;
    font-weight: bold;
    color: #4a9eff;
}

#streak {
    color: #ffd700;
}

/* Snake Area */
.snake-area {
    position: relative;
    min-height: 600px;
    height: 70vh;
    width: 100%;
    max-width: 800px;
    margin-bottom: 20px;
}

.snake-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

/* Problem Box */
.problem-box {
    position: absolute;
    width: 90px;
    min-height: 80px;
    background: rgba(19, 21, 25, 0.85);
    border: 2px solid rgba(255, 255, 255, 0.2);
    padding: 8px;
    backdrop-filter: blur(4px);
    transition: all 0.3s ease;
    border-radius: 4px;
}

.problem-box.current {
    border-color: #4a9eff;
    border-width: 3px;
    box-shadow: 0 0 10px rgba(74, 158, 255, 0.5);
    transform: scale(1.05);
    z-index: 10;
}

.problem-box.streak {
    border-color: #ffd700;
    border-width: 3px;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.6);
    background: rgba(255, 215, 0, 0.1);
}

.problem-box.behind {
    opacity: 0.6;
}

.problem-box.expired {
    opacity: 0.3;
    border-color: #ff4444;
}

/* Time bar colors */
.problem-box.time-ok .time-bar {
    background: #4a9eff;
}

.problem-box.time-warning .time-bar {
    background: #ffaa00;
}

.problem-box.time-critical .time-bar {
    background: #ff4444;
}

/* Problem Vertical Format */
.problem-vertical {
    text-align: center;
    font-family: 'Courier New', monospace;
    line-height: 1.4;
}

.problem-line {
    margin: 1px 0;
    font-size: 0.95em;
    color: #e0e0e0;
}

.problem-divider {
    color: #888;
    font-size: 0.9em;
    margin: 4px 0;
}

.problem-answer {
    margin-top: 4px;
    font-weight: bold;
    color: #4a9eff;
}

.problem-aging {
    position: absolute;
    top: 5px;
    right: 5px;
    font-size: 0.9em;
    color: #ffaa00;
    opacity: 0.9;
    font-weight: bold;
    text-shadow: 0 0 3px rgba(255, 170, 0, 0.8);
}

.answer-input {
    width: 50px;
    text-align: center;
    background: rgba(19, 21, 25, 0.9);
    border: 2px solid #4a9eff;
    color: #4a9eff;
    font-size: 1em;
    font-weight: bold;
    padding: 3px;
    font-family: 'Courier New', monospace;
    outline: none;
}

.answer-input:focus {
    border-color: #6bb6ff;
    box-shadow: 0 0 5px rgba(74, 158, 255, 0.5);
}

/* Time Bar */
.time-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    background: #4a9eff;
    transition: width 0.1s linear;
    border-radius: 0 0 2px 2px;
}

/* Feedback */
.feedback {
    text-align: center;
    font-size: 1.2em;
    font-weight: bold;
    margin: 20px 0;
    min-height: 30px;
}

.feedback.correct {
    color: #4aff4a;
}

.feedback.wrong {
    color: #ff4444;
}

.help-hint {
    text-align: center;
    color: #888;
    font-size: 0.9em;
    margin-top: 20px;
}

/* Level Up Animation */
.level-up {
    position: fixed;
    font-size: 2em;
    font-weight: bold;
    color: #ffd700;
    background: rgba(0, 0, 0, 0.9);
    padding: 30px;
    border: 3px solid #ffd700;
    z-index: 2000;
    animation: levelUpAnim 2s forwards;
    text-align: center;
}

@keyframes levelUpAnim {
    0% { transform: translate(-50%, -50%) scale(0.5); opacity: 0; }
    15% { transform: translate(-50%, -50%) scale(1.2); opacity: 1; }
    50% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(0.8); opacity: 0; }
}

/* Responsive */
@media (max-width: 768px) {
    .snake-area {
        min-height: 500px;
        height: 60vh;
    }
    
    .problem-box {
        width: 80px;
        min-height: 70px;
        padding: 6px;
    }
    
    .problem-line {
        font-size: 0.85em;
    }
    
    .answer-input {
        width: 45px;
        font-size: 0.9em;
    }
}