/* ===== CSS Variables ===== */
:root {
    /* Colors - Warm and Playful Palette */
    --color-sky: #87CEEB;
    --color-sky-light: #B0E0F6;
    --color-ground: #F4E4C1;
    --color-primary: #FF6B6B;
    --color-primary-hover: #FF5252;
    --color-secondary: #4ECDC4;
    --color-secondary-hover: #45B8AF;
    --color-text-dark: #2C3E50;
    --color-text-light: #FFFFFF;
    --color-shadow: rgba(0, 0, 0, 0.1);
    --color-shadow-strong: rgba(0, 0, 0, 0.2);
    --color-dino: #7CB342;
    --color-dino-dark: #689F38;
    --color-obstacle: #8B4513;
    --color-bird: #FF9800;

    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;

    /* Typography */
    --font-heading: 'Fredoka', sans-serif;
    --font-body: 'Inter', sans-serif;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-full: 50%;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-body);
    background: linear-gradient(to bottom, var(--color-sky-light) 0%, var(--color-sky) 100%);
    color: var(--color-text-dark);
    overflow: hidden;
    /* Disable all page scrolling */
    height: 100vh;
    /* Fixed viewport height */
    width: 100vw;
}

/* ===== Screen Management ===== */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    /* Fixed height instead of min-height */
    display: flex;
    align-items: flex-start;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
    overflow-y: auto;
    padding: var(--spacing-lg) 0;
}

.screen.active {
    opacity: 1;
    pointer-events: all;
}

.content-container {
    text-align: center;
    padding: var(--spacing-md);
    max-width: 600px;
    width: 100%;
    margin: auto;
}

/* ===== Typography ===== */
.game-title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 700;
    color: var(--color-text-dark);
    margin-bottom: var(--spacing-sm);
    text-shadow: 3px 3px 0 var(--color-shadow);
    animation: titleBounce 2s ease-in-out infinite;
}

.game-description {
    font-size: clamp(1rem, 3vw, 1.25rem);
    color: var(--color-text-dark);
    margin-bottom: var(--spacing-xl);
    font-weight: 500;
}

.screen-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 6vw, 3rem);
    font-weight: 700;
    color: var(--color-text-dark);
    margin-bottom: var(--spacing-lg);
}

/* ===== Buttons ===== */
.primary-btn,
.secondary-btn {
    font-family: var(--font-heading);
    font-size: clamp(1.25rem, 4vw, 1.75rem);
    font-weight: 600;
    padding: var(--spacing-sm) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 12px var(--color-shadow);
    min-width: 200px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.primary-btn {
    background: linear-gradient(135deg, var(--color-primary) 0%, #FF8E53 100%);
    color: var(--color-text-light);
}

.primary-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px var(--color-shadow-strong);
}

.primary-btn:active:not(:disabled) {
    transform: translateY(0);
}

.primary-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.secondary-btn {
    background: var(--color-text-light);
    color: var(--color-text-dark);
    border: 3px solid var(--color-secondary);
}

.secondary-btn:hover {
    background: var(--color-secondary);
    color: var(--color-text-light);
    transform: translateY(-2px);
}

/* ===== Background Elements ===== */
.background-elements {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
}

.cloud {
    position: absolute;
    width: 100px;
    height: 40px;
    background: white;
    border-radius: var(--radius-full);
    opacity: 0.8;
    animation: cloudFloat 20s linear infinite;
}

.cloud::before,
.cloud::after {
    content: '';
    position: absolute;
    background: white;
    border-radius: var(--radius-full);
}

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

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

.cloud-1 {
    top: 10%;
    left: -100px;
    animation-delay: 0s;
}

.cloud-2 {
    top: 30%;
    left: -100px;
    animation-delay: 7s;
}

.cloud-3 {
    top: 50%;
    left: -100px;
    animation-delay: 14s;
}

@keyframes cloudFloat {
    from {
        transform: translateX(0);
    }

    to {
        transform: translateX(calc(100vw + 100px));
    }
}

/* ===== Landing Screen ===== */
.dino-preview {
    margin: var(--spacing-lg) auto;
    width: 120px;
    height: 120px;
}

.dino-body,
.preview-body,
.gameover-body {
    width: 100%;
    height: 100%;
    background: var(--color-dino);
    border-radius: var(--radius-md);
    position: relative;
    box-shadow: 0 4px 8px var(--color-shadow);
}

.dino-body::before,
.preview-body::before,
.gameover-body::before {
    content: '';
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 40%;
    background: var(--color-dino-dark);
    border-radius: var(--radius-sm);
}

.bounce {
    animation: bounce 1s ease-in-out infinite;
}

@keyframes bounce {

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

    50% {
        transform: translateY(-20px);
    }
}

@keyframes titleBounce {

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

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

/* ===== Character Selection Screen ===== */
.character-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.character-card {
    background: white;
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: 0 2px 8px var(--color-shadow);
    border: 3px solid transparent;
}

.character-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 16px var(--color-shadow-strong);
}

.character-card.selected {
    border-color: var(--color-primary);
    transform: scale(1.05);
}

.character-avatar {
    width: 100%;
    aspect-ratio: 1;
    border-radius: var(--radius-full);
    object-fit: cover;
    margin-bottom: var(--spacing-xs);
    background: linear-gradient(135deg, var(--color-sky-light), var(--color-secondary));
}

.character-name {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-dark);
}

.character-preview {
    margin: var(--spacing-lg) auto;
    transition: opacity var(--transition-normal);
}

.character-preview.hidden {
    opacity: 0;
    height: 0;
    overflow: hidden;
}

.preview-dino {
    position: relative;
    width: 150px;
    height: 150px;
    margin: 0 auto var(--spacing-sm);
}

.preview-face-container {
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 40%;
    z-index: 2;
    border-radius: var(--radius-full);
    overflow: hidden;
    border: 3px solid var(--color-dino-dark);
}

.preview-face-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.preview-name {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text-dark);
}

/* ===== Game Screen ===== */
#game-screen {
    background: linear-gradient(to bottom, var(--color-sky) 0%, var(--color-sky-light) 100%);
    overflow: hidden;
    /* Prevent scrolling on game screen */
    padding: 0;
    /* Remove padding that creates scroll space */
}

.game-ui {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    right: var(--spacing-md);
    z-index: 10;
}

.score-display {
    background: white;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: 0 2px 8px var(--color-shadow);
    display: inline-block;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
}

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

#score {
    color: var(--color-primary);
}

#game-canvas {
    position: absolute;
    top: 0;
    left: 0;
    display: block;
    width: 100vw;
    height: 100vh;
}

.start-prompt {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 16px var(--color-shadow-strong);
    animation: pulse 1.5s ease-in-out infinite;
    pointer-events: none;
}

.start-prompt p {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin: 0;
}

@keyframes pulse {

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

    50% {
        transform: translate(-50%, -50%) scale(1.05);
    }
}

/* ===== Game Over Screen ===== */
.game-over-title {
    color: var(--color-primary);
}

.final-score-container {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    box-shadow: 0 4px 12px var(--color-shadow);
}

.final-score-label {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: var(--spacing-xs);
}

.final-score {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-primary);
}

.gameover-character {
    position: relative;
    width: 150px;
    height: 150px;
    margin: 0 auto var(--spacing-lg);
}

.gameover-face-container {
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 40%;
    z-index: 2;
    border-radius: var(--radius-full);
    overflow: hidden;
    border: 3px solid var(--color-dino-dark);
}

.gameover-face-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    align-items: center;
}

/* ===== Responsive Design ===== */
@media (min-width: 768px) {
    .button-group {
        flex-direction: row;
        justify-content: center;
    }

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

@media (max-width: 480px) {
    .character-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
    }

    .primary-btn,
    .secondary-btn {
        min-width: 150px;
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

/* ===== Leaderboard Screen ===== */
.leaderboard-list {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    box-shadow: 0 4px 12px var(--color-shadow);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.leaderboard-entry {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm);
    border-bottom: 2px solid #f0f0f0;
    transition: background var(--transition-fast);
}

.leaderboard-entry:last-child {
    border-bottom: none;
}

.leaderboard-entry:hover {
    background: #f8f8f8;
}

.leaderboard-rank {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    width: 50px;
    text-align: center;
}

.leaderboard-rank.gold {
    color: #FFD700;
}

.leaderboard-rank.silver {
    color: #C0C0C0;
}

.leaderboard-rank.bronze {
    color: #CD7F32;
}

.leaderboard-avatar {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    object-fit: cover;
    margin-right: var(--spacing-sm);
    border: 2px solid var(--color-secondary);
}

.leaderboard-info {
    flex: 1;
    text-align: left;
}

.leaderboard-name {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 4px;
}

.leaderboard-score {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    text-align: right;
}

.leaderboard-empty {
    text-align: center;
    padding: var(--spacing-xl);
    color: #999;
    font-size: 1.1rem;
}