:root {
    /* Shared Base */
    --transition-speed: 0.3s;
}

/* =========================================
   THEME: NEON (Default)
   ========================================= */
body.theme-neon {
    --bg-color: #050505;
    --card-bg: #111;
    --card-border: #333;
    --text-main: #fff;
    --text-title: #00f3ff;
    --text-accent: #ff00ff;
    --text-highlight: #00ff00;
    --shadow-color: rgba(0, 243, 255, 0.1);
    --shadow-hover: rgba(0, 243, 255, 0.3);
    --font-main: 'Orbitron', sans-serif;
    --title-shadow: 0 0 10px var(--text-title);
    --text-shadow-accent: 0 0 5px var(--text-accent);
    --text-shadow-highlight: 0 0 20px var(--text-highlight);
    --line-style: dashed;
    --line-opacity: 0.5;
    
    /* Analog Clock Specifics */
    --clock-face-border: 4px solid var(--text-highlight);
    --clock-face-bg: rgba(0, 255, 0, 0.05);
    --clock-hand-color: var(--text-highlight);
    --clock-shadow: 0 0 20px var(--text-highlight);
}

/* =========================================
   THEME: EXECUTIVE (Fancy Office)
   ========================================= */
body.theme-executive {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --card-border: #e1e4e8;
    --text-main: #2c3e50;
    --text-title: #2c3e50;
    --text-accent: #6c757d; /* City Name - Muted Grey */
    --text-highlight: #b8860b; /* Seconds/Date Line - Gold */
    --shadow-color: rgba(0, 0, 0, 0.05);
    --shadow-hover: rgba(0, 0, 0, 0.1);
    --font-main: 'Inter', sans-serif;
    --title-shadow: none;
    --text-shadow-accent: none;
    --text-shadow-highlight: none;
    --line-style: solid;
    --line-opacity: 0.2;

    /* Analog Clock Specifics */
    --clock-face-border: 4px solid #2c3e50;
    --clock-face-bg: #fff;
    --clock-hand-color: #b8860b; /* Gold hand */
    --clock-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

/* =========================================
   GLOBAL STYLES
   ========================================= */

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-main);
    display: flex;
    flex-direction: column; /* Changed to column to accommodate absolute controls better if needed, but centering still works */
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.controls {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 100;
}

.theme-select {
    padding: 8px 12px;
    border-radius: 5px;
    border: 1px solid var(--card-border);
    background: var(--card-bg);
    color: var(--text-main);
    font-family: var(--font-main);
    cursor: pointer;
    font-size: 0.9rem;
    outline: none;
    box-shadow: 0 2px 5px var(--shadow-color);
}

.container {
    text-align: center;
    width: 90%;
    max-width: 1200px;
    padding: 20px;
}

.title {
    font-size: 3rem;
    color: var(--text-title);
    text-shadow: var(--title-shadow);
    margin-bottom: 2rem;
    letter-spacing: 5px;
    transition: color var(--transition-speed);
}

.clocks-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 3rem;
}

.clock-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    padding: 20px;
    border-radius: 10px;
    width: 250px;
    box-shadow: 0 0 15px var(--shadow-color);
    transition: transform 0.3s, box-shadow 0.3s, background-color var(--transition-speed), border-color var(--transition-speed);
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.clock-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 25px var(--shadow-hover);
}

.city-name {
    font-size: 1.2rem;
    color: var(--text-accent);
    margin-bottom: 10px;
    text-transform: uppercase;
    text-shadow: var(--text-shadow-accent);
    font-weight: 600;
    letter-spacing: 1px;
}

.time-display {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: baseline;
}

.colon {
    animation: blink 1s steps(1) infinite;
    margin: 0 2px;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.date-display {
    font-size: 0.8rem;
    color: var(--text-accent);
    opacity: 0.8;
    margin-top: 5px;
}

/* Creative Date Change Indicator */
.date-change-marker {
    width: 100%; 
    text-align: center; 
    color: var(--text-highlight);
    margin: 20px 0;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    text-shadow: var(--text-shadow-highlight);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.date-change-marker::before, .date-change-marker::after {
    content: '';
    flex: 1;
    border-bottom: 1px var(--line-style) var(--text-highlight);
    margin: 0 15px;
    opacity: var(--line-opacity);
}

/* Analog Seconds Clock */
.seconds-container {
    margin-top: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

.analog-clock {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    border: var(--clock-face-border);
    background: var(--clock-face-bg);
    position: relative;
    box-shadow: var(--clock-shadow);
    transition: all 0.3s ease;
}

.center-dot {
    width: 10px;
    height: 10px;
    background: var(--clock-hand-color);
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    box-shadow: inherit;
    z-index: 10;
}

.hand {
    position: absolute;
    bottom: 50%;
    left: 50%;
    transform-origin: bottom center;
    background: var(--clock-hand-color);
    box-shadow: inherit;
    border-radius: 4px;
}

.seconds-hand {
    width: 2px;
    height: 45%;
    will-change: transform;
}