/* ========================================
   CSS RESET & ROOT VARIABLES
   ======================================== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette - Prehistoric Theme */
    --color-primary: #8B4513;
    --color-secondary: #228B22;
    --color-accent: #FF6347;
    --color-warning: #FFD700;
    --color-success: #32CD32;
    --color-error: #DC143C;
    
    --color-bg-main: #87CEEB;
    --color-bg-light: #F0E68C;
    --color-bg-dark: #654321;
    --color-text: #2F4F4F;
    --color-text-light: #FFFFFF;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Typography */
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 2.5rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-full: 50%;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ========================================
   BASE STYLES
   ======================================== */
html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background: linear-gradient(180deg, var(--color-bg-main) 0%, var(--color-bg-light) 100%);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Screen Reader Only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ========================================
   BACKGROUND ANIMATED ELEMENTS
   ======================================== */
.background-elements {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.volcano {
    position: absolute;
    bottom: -20px;
    width: 0;
    height: 0;
    border-left: 80px solid transparent;
    border-right: 80px solid transparent;
    border-bottom: 150px solid var(--color-bg-dark);
    opacity: 0.3;
}

.volcano::before {
    content: '🌋';
    position: absolute;
    top: -30px;
    left: -15px;
    font-size: 2rem;
}

.volcano-1 {
    left: 5%;
}

.volcano-2 {
    right: 10%;
}

.cloud {
    position: absolute;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 100px;
    animation: float-clouds 60s linear infinite;
}

.cloud::before,
.cloud::after {
    content: '';
    position: absolute;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 100px;
}

.cloud-1 {
    width: 100px;
    height: 40px;
    top: 10%;
    left: -150px;
    animation-duration: 50s;
}

.cloud-1::before {
    width: 50px;
    height: 50px;
    top: -25px;
    left: 10px;
}

.cloud-1::after {
    width: 60px;
    height: 40px;
    top: -15px;
    right: 10px;
}

.cloud-2 {
    width: 120px;
    height: 50px;
    top: 25%;
    left: -200px;
    animation-duration: 70s;
    animation-delay: 10s;
}

.cloud-2::before {
    width: 60px;
    height: 60px;
    top: -30px;
    left: 15px;
}

.cloud-2::after {
    width: 70px;
    height: 50px;
    top: -20px;
    right: 15px;
}

.cloud-3 {
    width: 90px;
    height: 35px;
    top: 50%;
    left: -100px;
    animation-duration: 55s;
    animation-delay: 20s;
}

.cloud-3::before {
    width: 45px;
    height: 45px;
    top: -20px;
    left: 10px;
}

.cloud-3::after {
    width: 55px;
    height: 35px;
    top: -15px;
    right: 10px;
}

@keyframes float-clouds {
    from {
        transform: translateX(0);
    }
    to {
        transform: translateX(calc(100vw + 200px));
    }
}

.palm {
    position: absolute;
    bottom: 0;
    font-size: 4rem;
    opacity: 0.4;
    animation: sway 4s ease-in-out infinite;
}

.palm::before {
    content: '🌴';
}

.palm-1 {
    left: 15%;
}

.palm-2 {
    right: 20%;
    animation-delay: 2s;
}

@keyframes sway {
    0%, 100% {
        transform: rotate(-2deg);
    }
    50% {
        transform: rotate(2deg);
    }
}

/* ========================================
   MAIN CONTAINER
   ======================================== */
.game-container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: calc(100vh - 60px);
}

/* ========================================
   HEADER
   ======================================== */
.game-header {
    background: rgba(255, 255, 255, 0.98);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    margin-bottom: var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    border: 2px solid rgba(255, 255, 255, 0.8);
}

.game-title {
    font-size: var(--font-size-2xl);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
}

.dino-icon {
    font-size: var(--font-size-3xl);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.score-board {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.score {
    background: var(--color-warning);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: bold;
    box-shadow: var(--shadow-sm);
}

.score .label {
    margin-right: var(--spacing-xs);
}

.score .value {
    font-size: var(--font-size-xl);
    color: var(--color-primary);
}

.lives {
    font-size: var(--font-size-xl);
}

/* ========================================
   SCREENS
   ======================================== */
.screen {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   WELCOME SCREEN
   ======================================== */
.welcome-content {
    background: rgba(255, 255, 255, 0.98);
    padding: var(--spacing-xxl);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    text-align: center;
    border: 2px solid rgba(255, 255, 255, 0.8);
}

.dino-large {
    font-size: 6rem;
    margin-bottom: var(--spacing-md);
    animation: wiggle 1s ease-in-out infinite;
}

@keyframes wiggle {
    0%, 100% {
        transform: rotate(-5deg);
    }
    50% {
        transform: rotate(5deg);
    }
}

.welcome-content h2 {
    font-size: var(--font-size-2xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.welcome-content p {
    font-size: var(--font-size-lg);
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
}

.difficulty-selector h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-md);
    color: var(--color-secondary);
}

.difficulty-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.btn-difficulty {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    padding: var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-secondary), var(--color-primary));
    color: var(--color-text-light);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    font-weight: 600;
}

.btn-difficulty:hover,
.btn-difficulty:focus {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.btn-difficulty .icon {
    font-size: 2.5rem;
}

.btn-difficulty .sub {
    font-size: var(--font-size-sm);
    opacity: 0.9;
}

/* ========================================
   GAME SCREEN
   ======================================== */
.game-content {
    background: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.question-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.dino-avatar {
    flex-shrink: 0;
    font-size: 4rem;
}

#dino-emoji {
    display: inline-block;
    animation: dino-talk 0.5s ease-in-out;
}

@keyframes dino-talk {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}

.question-bubble {
    background: var(--color-bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    position: relative;
    flex: 1;
    box-shadow: var(--shadow-sm);
}

.question-bubble::before {
    content: '';
    position: absolute;
    left: -15px;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-right: 15px solid var(--color-bg-light);
}

.question-text {
    font-size: var(--font-size-2xl);
    font-weight: bold;
    color: var(--color-primary);
    text-align: center;
}

.answer-section {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.answer-input {
    flex: 1;
    padding: var(--spacing-md);
    font-size: var(--font-size-xl);
    border: 3px solid var(--color-primary);
    border-radius: var(--radius-md);
    text-align: center;
    font-weight: bold;
    transition: all var(--transition-fast);
}

.answer-input:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(255, 99, 71, 0.2);
}

.answer-input.correct {
    border-color: var(--color-success);
    background: rgba(50, 205, 50, 0.1);
}

.answer-input.incorrect {
    border-color: var(--color-error);
    background: rgba(220, 20, 60, 0.1);
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-10px);
    }
    75% {
        transform: translateX(10px);
    }
}

.btn {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-lg);
    font-weight: bold;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
}

.btn:focus {
    outline: 3px solid var(--color-accent);
    outline-offset: 2px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent), var(--color-primary));
    color: var(--color-text-light);
}

.btn-primary:hover:not(:disabled),
.btn-primary:focus:not(:disabled) {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.feedback {
    min-height: 60px;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
    font-size: var(--font-size-xl);
    font-weight: bold;
    margin-bottom: var(--spacing-md);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.feedback.show {
    opacity: 1;
}

.feedback.success {
    background: var(--color-success);
    color: var(--color-text-light);
    animation: celebrate 0.5s ease;
}

.feedback.error {
    background: var(--color-error);
    color: var(--color-text-light);
}

@keyframes celebrate {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1) rotate(2deg);
    }
}

.progress-bar {
    position: relative;
    width: 100%;
    height: 40px;
    background: rgba(0, 0, 0, 0.1);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-success), var(--color-secondary));
    transition: width var(--transition-slow);
    border-radius: var(--radius-full);
}

.progress-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-weight: bold;
    color: var(--color-text);
    text-shadow: 0 0 3px rgba(255, 255, 255, 0.8);
}

/* ========================================
   GAME OVER SCREEN
   ======================================== */
.gameover-content {
    background: rgba(255, 255, 255, 0.95);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.result-dino {
    font-size: 6rem;
    margin-bottom: var(--spacing-md);
}

.gameover-content h2 {
    font-size: var(--font-size-2xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.gameover-content p {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
}

.final-score {
    background: var(--color-warning);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: var(--font-size-2xl);
    font-weight: bold;
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.final-score .value {
    color: var(--color-primary);
    display: block;
    font-size: var(--font-size-3xl);
}

/* ========================================
   FOOTER
   ======================================== */
.game-footer {
    text-align: center;
    padding: var(--spacing-md);
    color: white;
    font-size: var(--font-size-sm);
}
.game-footer p { color: white; }
.game-footer a { color: white; text-decoration: none; font-weight: bold; }
.game-footer a:hover { color: #ffd166; text-decoration: underline; }

/* ========================================
   RESPONSIVE DESIGN (Mobile First)
   ======================================== */
@media (max-width: 768px) {
    :root {
        --font-size-base: 14px;
    }

    .game-header {
        flex-direction: column;
        text-align: center;
    }

    .game-title {
        justify-content: center;
    }

    .difficulty-buttons {
        grid-template-columns: 1fr;
    }

    .question-container {
        flex-direction: column;
        text-align: center;
    }

    .question-bubble::before {
        display: none;
    }

    .answer-section {
        flex-direction: column;
    }

    .volcano {
        border-left-width: 50px;
        border-right-width: 50px;
        border-bottom-width: 100px;
    }
}

@media (max-width: 480px) {
    .game-container {
        padding: var(--spacing-sm);
    }

    .dino-large,
    .result-dino {
        font-size: 4rem;
    }

    .question-text {
        font-size: var(--font-size-xl);
    }
}

/* ========================================
   PRINT STYLES
   ======================================== */
@media print {
    .background-elements,
    .game-footer {
        display: none;
    }
}