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

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #77BEF0 0%, #FFCB61 100%);
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: bold;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.exercise-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
    margin-bottom: 30px;
}

.exercise-btn {
    background: white;
    border: 3px solid transparent;
    border-radius: 12px;
    padding: 15px 10px;
    font-size: 0.9rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #333;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.exercise-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.exercise-btn.active {
    background: #FF894F;
    color: white;
    border-color: #EA5B6F;
}

.exercise-content {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.1);
    position: relative;
}

.exercise {
    display: none;
}

.exercise.active {
    display: block;
}

.exercise-image {
    text-align: center;
    margin-bottom: 25px;
    position: relative;
}


.exercise-image img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}

.image-placeholder {
    background: #f0f0f0;
    border: 2px dashed #ccc;
    border-radius: 12px;
    padding: 60px 20px;
    color: #666;
    font-size: 1.1rem;
    text-align: center;
}

.exercise-info h2 {
    color: #FF894F;
    font-size: 2rem;
    margin-bottom: 20px;
    text-align: center;
}

.exercise-tips {
    background: #f8f9fa;
    border-left: 4px solid #77BEF0;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
}

.exercise-tips li {
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
}

.exercise-protocol {
    background: #77BEF0;
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 25px;
    text-align: center;
}

.exercise-protocol strong {
    font-size: 1.1rem;
}

.timer-controls {
    text-align: center;
}

.play-pause-btn {
    background: #008000;
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 1.2rem;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 20px;
}

.play-pause-btn:hover {
    background: #d14456;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(234, 91, 111, 0.4);
}

.play-pause-btn[data-state="pause"] {
    background: #FF894F;
}

.play-pause-btn[data-state="pause"]:hover {
    background: #e67a42;
}

.timer-display {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.timer-display span {
    background: #f8f9fa;
    padding: 10px 15px;
    border-radius: 20px;
    font-weight: bold;
    color: #333;
    border: 2px solid #e9ecef;
}

.main-timer {
    text-align: center;
    margin: 30px 0;
}

.timer-countdown-big {
    font-size: 6rem;
    font-weight: bold;
    color: #008000;
    margin: 15px 0;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.exercise-instruction {
    font-size: 1.4rem;
    color: #FF894F;
    font-weight: bold;
    margin: 15px 0;
    min-height: 2rem;
}

.timer-countdown {
    background: #FFCB61 !important;
    color: #333 !important;
    font-size: 1.2rem !important;
    font-weight: bold !important;
}

.rest-overlay,
.completion-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.rest-content,
.completion-content {
    background: white;
    padding: 40px;
    border-radius: 16px;
    text-align: center;
    max-width: 400px;
    margin: 20px;
}

.rest-content h3,
.completion-content h3 {
    color: #FF894F;
    font-size: 2rem;
    margin-bottom: 20px;
}

.rest-timer {
    font-size: 4rem;
    font-weight: bold;
    color: #EA5B6F;
    margin: 20px 0;
}

.completion-content button {
    background: #77BEF0;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 1.1rem;
    cursor: pointer;
    margin: 10px;
    transition: background 0.3s ease;
}

.completion-content button:hover {
    background: #5ca3d6;
}

#next-exercise-btn {
    background: #EA5B6F !important;
}

#next-exercise-btn:hover {
    background: #d14456 !important;
}

.next-exercise-text {
    margin-bottom: 10px;
}

.hidden {
    display: none !important;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 2rem;
    }

    header p {
        font-size: 1rem;
    }

    .exercise-selector {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .exercise-btn {
        padding: 12px 8px;
        font-size: 0.8rem;
    }

    .exercise-content {
        padding: 20px;
    }

    .exercise-info h2 {
        font-size: 1.6rem;
    }

    .timer-display {
        gap: 10px;
    }

    .timer-display span {
        padding: 8px 12px;
        font-size: 0.9rem;
    }
    
    .timer-countdown-big {
        font-size: 4rem;
    }
    
    .exercise-instruction {
        font-size: 1.2rem;
    }

    .start-btn {
        padding: 12px 30px;
        font-size: 1rem;
    }

    .rest-content,
    .completion-content {
        padding: 30px 20px;
        margin: 15px;
    }

    .rest-timer {
        font-size: 3rem;
    }
    
    .timer-countdown-big {
        font-size: 3.5rem;
    }
    
    .exercise-instruction {
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .exercise-selector {
        grid-template-columns: 1fr;
    }

    .exercise-btn {
        padding: 15px;
    }

    .timer-display {
        flex-direction: column;
        gap: 8px;
        align-items: center;
    }

    .image-placeholder {
        padding: 40px 15px;
        font-size: 1rem;
    }
}