:root {
    --bg-color: #0a0a0a;
    --text-color: #ffffff;
    --primary-color: #00ff9d;
    /* Neon Green */
    --warmup-color: #ff9d00;
    /* Orange */
    --sprint-color: #ff0055;
    /* Pink/Red */
    --rest-color: #00d9ff;
    /* Cyan */
    --cooldown-color: #9d00ff;
    /* Purple */
    --card-bg: #1a1a1a;
    --input-bg: #2a2a2a;
    --font-main: 'Outfit', sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    transition: background-color 0.5s ease;
}

#app {
    width: 100%;
    max-width: 600px;
    height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
}

.screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    transition: opacity 0.3s ease;
}

.hidden {
    display: none !important;
    opacity: 0;
}

/* Setup Screen */
h1 {
    font-weight: 900;
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 2px;
    background: linear-gradient(45deg, var(--primary-color), var(--rest-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.config-grid {
    display: grid;
    grid-template-columns: auto auto;
    justify-content: center;
    gap: 2rem;
    width: 100%;
    margin-bottom: 2rem;
}

.config-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.config-item:last-child {
    grid-column: span 2;
}

label {
    font-size: 0.9rem;
    color: #888;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    font-weight: 700;
}

input {
    background: var(--input-bg);
    border: 2px solid transparent;
    border-radius: 8px;
    color: white;
    padding: 1rem;
    font-size: 1.5rem;
    font-family: var(--font-main);
    font-weight: 700;
    text-align: center;
    outline: none;
    transition: border-color 0.2s;
}

input:focus {
    border-color: var(--primary-color);
}

.primary-btn {
    background: var(--primary-color);
    color: black;
    border: none;
    padding: 1.2rem 3rem;
    font-size: 1.5rem;
    font-weight: 900;
    border-radius: 50px;
    cursor: pointer;
    text-transform: uppercase;
    box-shadow: 0 0 20px rgba(0, 255, 157, 0.4);
    transition: transform 0.1s, box-shadow 0.2s;
}

.primary-btn:active {
    transform: scale(0.95);
    box-shadow: 0 0 10px rgba(0, 255, 157, 0.2);
}

/* Workout Screen */
.header-info {
    position: absolute;
    top: 5rem;
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 0 2rem;
    box-sizing: border-box;
    font-weight: 700;
    opacity: 0.7;
}

.main-display {
    text-align: center;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.phase-label {
    font-size: 3rem;
    font-weight: 900;
    text-transform: uppercase;
    margin-bottom: 1rem;
    letter-spacing: 5px;
    text-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
}

.giant-timer {
    font-size: 10rem;
    font-weight: 900;
    line-height: 1;
    font-variant-numeric: tabular-nums;
    text-shadow: 0 0 30px rgba(0, 0, 0, 0.5);
}

.next-phase {
    margin-top: 2rem;
    font-size: 1.2rem;
    opacity: 0.8;
}

.controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.icon-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    padding: 1rem 2rem;
    border-radius: 30px;
    font-weight: 700;
    cursor: pointer;
    text-transform: uppercase;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.lang-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    z-index: 100;
    font-size: 0.9rem;
    padding: 0.8rem 1.5rem;
}

.progress-container {
    width: 100%;
    height: 10px;
    background: rgba(255, 255, 255, 0.1);
    position: absolute;
    bottom: 0;
    left: 0;
}

.progress-bar {
    height: 100%;
    background: white;
    width: 100%;
    transform-origin: left;
    transition: width 1s linear;
}

/* Phase Specific Styles applied via JS classes on Body or Container */
body.warmup {
    background-color: #221400;
}

body.warmup .phase-label {
    color: var(--warmup-color);
}

body.warmup .giant-timer {
    color: var(--warmup-color);
}

body.sprint {
    background-color: #22000b;
    animation: pulse-fast 0.5s infinite alternate;
}

body.sprint .phase-label {
    color: var(--sprint-color);
}

body.sprint .giant-timer {
    color: var(--sprint-color);
}

body.rest {
    background-color: #00141a;
}

body.rest .phase-label {
    color: var(--rest-color);
}

body.rest .giant-timer {
    color: var(--rest-color);
}

body.cooldown {
    background-color: #140022;
}

body.cooldown .phase-label {
    color: var(--cooldown-color);
}

body.cooldown .giant-timer {
    color: var(--cooldown-color);
}

@keyframes pulse-fast {
    from {
        box-shadow: inset 0 0 50px rgba(255, 0, 85, 0.2);
    }

    to {
        box-shadow: inset 0 0 100px rgba(255, 0, 85, 0.4);
    }
}