:root {
    --neon-color: #0ff;
    --neon-border: #08f;
}

body {
    margin: 0;
    min-height: 100vh;
    background: linear-gradient(45deg, #000428, #004e92);
    font-family: 'Orbitron', sans-serif;
    color: white;
    overflow: hidden;
    position: relative;
}

body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 50% 50%, rgba(0,255,255,0.1) 0%, transparent 50%),
        linear-gradient(45deg, rgba(0,0,0,0.2) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(0,0,0,0.2) 25%, transparent 25%);
    background-size: 100% 100%, 20px 20px, 20px 20px;
    animation: backgroundMove 20s linear infinite;
    z-index: 0;
}

.container {
    position: relative;
    z-index: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.glass-panel {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.2);
    text-align: center;
}

.neon-text {
    color: var(--neon-color);
    text-shadow: 0 0 10px var(--neon-color),
                 0 0 20px var(--neon-color),
                 0 0 30px var(--neon-color);
    margin-bottom: 30px;
}

.timer-display {
    font-size: 4em;
    font-weight: bold;
    color: var(--neon-color);
    text-shadow: 0 0 20px var(--neon-color);
    margin: 30px 0;
}

.cyber-button {
    background: transparent;
    color: var(--neon-color);
    border: 2px solid var(--neon-color);
    padding: 10px 20px;
    margin: 10px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 2px;
    box-shadow: 0 0 10px var(--neon-border);
    position: relative;
    overflow: hidden;
}

.cyber-button:hover {
    background: var(--neon-color);
    color: black;
    box-shadow: 0 0 20px var(--neon-color);
    transform: translateY(-2px);
}

.sound-option {
    margin-top: 30px;
}

.sound-option label {
    margin-right: 10px;
}

@keyframes backgroundMove {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: 100px 100px;
    }
}

input[type="checkbox"] {
    appearance: none;
    width: 50px;
    height: 25px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 25px;
    position: relative;
    cursor: pointer;
    border: 2px solid var(--neon-color);
}

input[type="checkbox"]::before {
    content: '';
    width: 21px;
    height: 21px;
    background: var(--neon-color);
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 2px;
    transition: 0.3s;
}

input[type="checkbox"]:checked::before {
    left: 27px;
}

.custom-time {
    margin: 20px 0;
    display: flex;
    justify-content: center;
    gap: 10px;
    align-items: center;
}

.cyber-input {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid var(--neon-color);
    color: var(--neon-color);
    padding: 8px 12px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1em;
    width: 100px;
    border-radius: 5px;
    outline: none;
    text-align: center;
}

.cyber-input:focus {
    box-shadow: 0 0 15px var(--neon-color);
}

.cyber-input::placeholder {
    color: rgba(0, 255, 255, 0.5);
}

/* Remove spinner buttons from number input */
.cyber-input::-webkit-inner-spin-button,
.cyber-input::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

@keyframes flash {
    0%, 50%, 100% {
        background: linear-gradient(45deg, #000428, #004e92);
    }
    25%, 75% {
        background: var(--neon-color);
    }
}

.flash {
    animation: flash 0.5s ease-in-out 5;
}


.credits {
    position: fixed;
    bottom: 10px;
    width: 100%;
    text-align: center;
    font-size: 0.8em;
    color: rgba(0, 255, 255, 0.3);
    z-index: 1;
}

.credit-link {
    color: rgba(0, 255, 255, 0.5);
    text-decoration: none;
    transition: all 0.3s ease;
}

.credit-link:hover {
    color: var(--neon-color);
    text-shadow: 0 0 5px var(--neon-color);
}


/* Theme: Minimal */
.theme-minimal .glass-panel {
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.theme-minimal .timer-display {
    color: #333;
    text-shadow: none;
    font-family: 'Arial', sans-serif;
}

.theme-minimal .cyber-button {
    background: #f0f0f0;
    color: #333;
    border: 1px solid #ddd;
    box-shadow: none;
}

.theme-minimal .cyber-button:hover {
    background: #e0e0e0;
}

/* Theme: Retro */
.theme-retro {
    background: #2c3e50;
}

.theme-retro .glass-panel {
    background: #34495e;
    border: 4px solid #f1c40f;
    box-shadow: 0 0 20px rgba(241, 196, 15, 0.3);
}

.theme-retro .timer-display {
    font-family: 'Press Start 2P', cursive;
    color: #f1c40f;
    text-shadow: 2px 2px 0px #e67e22;
}

.theme-retro .cyber-button {
    background: #e67e22;
    color: #fff;
    border: 2px solid #f1c40f;
    font-family: 'Press Start 2P', cursive;
    text-transform: uppercase;
    font-size: 0.8em;
}

.theme-retro .cyber-button:hover {
    background: #f1c40f;
}

.theme-selector select {
    min-width: 150px;
    padding: 5px 10px;
}


/* Theme: Nature */
.theme-nature {
    background: linear-gradient(to bottom, #93c572, #2d5a27);
}

.theme-nature .glass-panel {
    background: rgba(255, 255, 255, 0.15);
    border: 2px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.2);
}

.theme-nature .timer-display {
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    font-family: 'Helvetica', sans-serif;
}

.theme-nature .cyber-button {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.4);
    color: white;
}

.theme-nature .cyber-button:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Theme: Space */
.theme-space {
    background: #000000 url('data:image/svg+xml,<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><circle cx="10" cy="10" r="1" fill="white"/></svg>') repeat;
}

.theme-space .glass-panel {
    background: rgba(25, 25, 50, 0.7);
    border: 1px solid rgba(100, 100, 255, 0.3);
    box-shadow: 0 0 20px rgba(100, 100, 255, 0.2);
}

.theme-space .timer-display {
    color: #00ffff;
    text-shadow: 0 0 10px #00ffff;
    font-family: 'Orbitron', sans-serif;
}

.theme-space .cyber-button {
    background: rgba(0, 255, 255, 0.1);
    border: 1px solid #00ffff;
    color: #00ffff;
}

.theme-space .cyber-button:hover {
    background: rgba(0, 255, 255, 0.2);
}

/* Theme: Synthwave */
.theme-synthwave {
    background: linear-gradient(to bottom, #2b1055, #7597de);
}

.theme-synthwave .glass-panel {
    background: rgba(255, 0, 255, 0.1);
    border: 2px solid rgba(255, 0, 255, 0.2);
    box-shadow: 0 0 20px rgba(255, 0, 255, 0.3);
}

.theme-synthwave .timer-display {
    color: #ff00ff;
    text-shadow: 0 0 10px #ff00ff, 0 0 20px #ff00ff;
    font-family: 'Orbitron', sans-serif;
}

.theme-synthwave .cyber-button {
    background: rgba(255, 0, 255, 0.1);
    border: 1px solid #ff00ff;
    color: #ff00ff;
    text-shadow: 0 0 5px #ff00ff;
}

.theme-synthwave .cyber-button:hover {
    background: rgba(255, 0, 255, 0.2);
}

/* Theme: Matrix */
.theme-matrix {
    background: #000000;
    position: relative;
}

.theme-matrix::before {
    content: '01';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.1;
    font-family: 'Courier New', monospace;
    font-size: 20px;
    color: #00ff00;
    white-space: nowrap;
    overflow: hidden;
}

.theme-matrix .glass-panel {
    background: rgba(0, 255, 0, 0.1);
    border: 1px solid #00ff00;
    box-shadow: 0 0 20px rgba(0, 255, 0, 0.3);
}

.theme-matrix .timer-display {
    color: #00ff00;
    text-shadow: 0 0 10px #00ff00;
    font-family: 'Courier New', monospace;
}

.theme-matrix .cyber-button {
    background: transparent;
    border: 1px solid #00ff00;
    color: #00ff00;
    font-family: 'Courier New', monospace;
}

.theme-matrix .cyber-button:hover {
    background: rgba(0, 255, 0, 0.2);
}

/* Theme: Sunset */
.theme-sunset {
    background: linear-gradient(45deg, #ff512f, #dd2476);
}

.theme-sunset .glass-panel {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 20px rgba(255, 81, 47, 0.3);
}

.theme-sunset .timer-display {
    color: #ffffff;
    text-shadow: 0 0 15px rgba(255, 81, 47, 0.8);
    font-family: 'Arial', sans-serif;
}

.theme-sunset .cyber-button {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.4);
    color: white;
}

.theme-sunset .cyber-button:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Theme: Ocean */
.theme-ocean {
    background: linear-gradient(to bottom, #1a2980, #26d0ce);
}

.theme-ocean .glass-panel {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 0 20px rgba(38, 208, 206, 0.3);
}

.theme-ocean .timer-display {
    color: #ffffff;
    text-shadow: 0 0 15px rgba(38, 208, 206, 0.8);
    font-family: 'Helvetica', sans-serif;
}

.theme-ocean .cyber-button {
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
}

.theme-ocean .cyber-button:hover {
    background: rgba(255, 255, 255, 0.25);
}

/* Theme: Neon */
.theme-neon {
    background: #111;
}

.theme-neon .glass-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid #ff00ff;
    box-shadow: 0 0 20px rgba(255, 0, 255, 0.3),
                inset 0 0 20px rgba(255, 0, 255, 0.2);
}

.theme-neon .timer-display {
    color: #ff00ff;
    text-shadow: 0 0 10px #ff00ff,
                 0 0 20px #ff00ff,
                 0 0 30px #ff00ff;
    font-family: 'Orbitron', sans-serif;
}

.theme-neon .cyber-button {
    background: transparent;
    border: 2px solid #00ffff;
    color: #00ffff;
    text-shadow: 0 0 5px #00ffff;
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.3),
                inset 0 0 10px rgba(0, 255, 255, 0.2);
}

.theme-neon .cyber-button:hover {
    background: rgba(0, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5),
                inset 0 0 15px rgba(0, 255, 255, 0.3);
}