:root {
    --primary: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #6366f1;
    --accent: #f59e0b;
    --accent-hover: #d97706;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --success: #22c55e;
    --error: #ef4444;
    --white: #ffffff;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    overflow: hidden;
    height: 100vh;
}

/* Progress Bar */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 6px;
    background: linear-gradient(to right, var(--primary), var(--accent));
    z-index: 1000;
    transition: width 0.3s ease;
}

/* Indicators (Score & Timer) */
.score-display,
.timer-display {
    position: fixed;
    top: 2rem;
    background: var(--white);
    padding: 0.8rem 1.5rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--primary);
    z-index: 1000;
    display: none;
    border: 3px solid var(--primary);
    animation: slideInDown 0.5s ease-out;
}

.score-display { right: 2rem; }
.timer-display { right: 12rem; }

@keyframes slideInDown {
    from { transform: translateY(-100%); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* Slide System */
.slide-container {
    display: flex;
    height: 100vh;
    width: 100%;
    transition: transform 0.8s cubic-bezier(0.65, 0, 0.35, 1);
}

.slide {
    min-width: 100vw;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4rem;
    position: relative;
    opacity: 0.3;
    transition: opacity 0.5s;
}

.slide.active { opacity: 1; }

.content {
    display: flex;
    align-items: center;
    gap: 4rem;
    max-width: 1200px;
    width: 100%;
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 3rem;
    box-shadow: var(--shadow-lg);
    transition: transform 0.5s;
}

.slide.active .content { transform: scale(1); }
.slide:not(.active) .content { transform: scale(0.95); }

.slide:nth-child(even) .content { flex-direction: row-reverse; }

/* Components */
.image-box {
    flex: 1;
    height: 500px;
    border-radius: 2rem;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.image-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.text-box {
    flex: 1;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

h1 {
    font-family: 'Quicksand', sans-serif;
    font-size: 4rem;
    color: var(--primary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

p {
    font-size: 1.8rem;
    line-height: 1.4;
    color: var(--text-muted);
    margin-bottom: 2rem;
    display: flex;
    align-items: flex-start;
    gap: 0.8rem;
}

/* Interactive Buttons */
.speaker-btn, .sentence-speaker-btn {
    background: #f1f5f9;
    border: none;
    cursor: pointer;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.speaker-btn { font-size: 2rem; width: 60px; height: 60px; }
.sentence-speaker-btn { font-size: 1.2rem; width: 40px; height: 40px; margin-top: 0.5rem; }

.speaker-btn:hover, .sentence-speaker-btn:hover {
    transform: scale(1.1);
    background: #e2e8f0;
    color: var(--primary);
}

/* Game: Guess the Word */
.hidden-text h1, .hidden-text p {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.5s ease;
}

.hidden-text .speaker-btn, .hidden-text .sentence-speaker-btn { display: none; }

.reveal-btn {
    background: var(--accent);
    color: var(--white);
    border: none;
    padding: 1.5rem 3rem;
    font-size: 1.8rem;
    font-weight: 800;
    border-radius: 2rem;
    cursor: pointer;
    box-shadow: 0 10px 20px rgba(245, 158, 11, 0.3);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.4); }
    70% { transform: scale(1.05); box-shadow: 0 0 0 15px rgba(245, 158, 11, 0); }
    100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0); }
}

/* Game: Fill in Blanks */
.blank-container {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.letter-input {
    width: 50px;
    height: 70px;
    font-size: 2.5rem;
    text-align: center;
    border: 4px solid #e2e8f0;
    border-radius: 12px;
    font-family: 'Outfit', sans-serif;
    font-weight: 800;
    text-transform: uppercase;
    outline: none;
    transition: all 0.2s;
}

.letter-input.correct { border-color: var(--success); background-color: #f0fdf4; color: var(--success); }
.letter-input.incorrect { border-color: var(--error); background-color: #fef2f2; color: var(--error); }

/* Results Slide */
.results-box {
    text-align: center;
    background: var(--white);
    padding: 4rem;
    border-radius: 3rem;
    box-shadow: var(--shadow-lg);
}

.results-score { font-size: 6rem; font-weight: 800; color: var(--accent); margin: 0.5rem 0; }
.results-time { font-size: 2.5rem; color: var(--primary); margin-bottom: 2rem; }

.restart-btn {
    background: var(--primary);
    color: var(--white);
    border: none;
    padding: 1.5rem 3.5rem;
    font-size: 1.6rem;
    font-weight: bold;
    border-radius: 1.5rem;
    cursor: pointer;
    transition: all 0.2s;
}

.restart-btn:hover { transform: translateY(-5px) scale(1.05); box-shadow: 0 10px 20px rgba(79, 70, 229, 0.3); }

/* Bottom Controls */
.controls {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 1rem;
    z-index: 100;
}

.nav-buttons { display: flex; gap: 1rem; }

.nav-btn {
    background: var(--white);
    border: none;
    color: var(--primary);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}

.nav-btn:hover { background: var(--primary); color: var(--white); transform: translateY(-2px); }

.topic-label {
    font-size: 1rem;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 2px;
    background: white;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    box-shadow: var(--shadow);
}

/* Menu Overlay */
.menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(79, 70, 229, 0.95);
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1500;
    backdrop-filter: blur(10px);
}

.menu-title { color: var(--white); font-size: 3rem; font-weight: 800; margin-bottom: 2rem; font-family: 'Quicksand', sans-serif; }
.menu-item { color: var(--white); font-size: 2rem; margin: 1rem 0; cursor: pointer; transition: all 0.3s; opacity: 0.8; font-weight: 600; text-align: center; }
.menu-item:hover { opacity: 1; transform: scale(1.1); color: var(--accent); }
.close-menu { position: absolute; top: 2rem; right: 2rem; background: none; border: 2px solid var(--white); color: var(--white); width: 60px; height: 60px; border-radius: 50%; font-size: 2rem; cursor: pointer; }

/* Intro Title Slide */
.title-slide h1 { font-size: 6rem; margin-bottom: 0.5rem; }
.title-slide h2 { font-size: 4rem; color: var(--accent); font-family: 'Quicksand', sans-serif; }
.start-hint { margin-top: 3rem; font-size: 1.5rem; opacity: 0.5; font-weight: 600; }