:root {
    /* Light Theme Variables */
    --bg-color-light: #f8f9fa;
    --text-color-light: #212529;
    --accent-color-light: #007bff;
    --accent-hover-light: #0056b3;
    --stop-color-light: #dc3545;
    --stop-hover-light: #c82333;
    --icon-color-light: var(--accent-color-light); /* For h1 icon */
    --icon-on-light-button: #ffffff; /* For session button icon in light mode */
    --switch-bg-light: #ced4da;
    --switch-knob-light: #ffffff;
    --switch-active-bg-light: var(--accent-color-light);

    /* Dark Theme Variables */
    --bg-color-dark: #121212;
    --text-color-dark: #e9ecef;
    --icon-on-dark-button: #f0f0f0; /* Light color for icons on dark buttons */
    --accent-color-dark: #3793ff; 
    --accent-hover-dark: #0d6efd;
    --stop-color-dark: #e53e3e; 
    --stop-hover-dark: #c93030;
    --icon-color-dark: var(--accent-color-dark); /* For h1 icon */
    --switch-bg-dark: #495057;
    --switch-knob-dark: #343a40;
    --switch-active-bg-dark: var(--accent-color-dark);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    padding: 1rem; 
    background-color: var(--bg-color-light);
    color: var(--text-color-light);
    transition: background-color 0.3s, color 0.3s;
    box-sizing: border-box; 
}

h1 {
    margin-bottom: 2rem; 
    color: var(--text-color-light);
    font-size: 2.5rem; 
    font-weight: 600;
    transition: color 0.3s;
    text-align: center; /* May be overridden by flex, but good fallback */
    display: flex;
    align-items: center;
    justify-content: center; /* To keep h1 content centered */
}

#sessionToggleButton {
    background-color: var(--accent-color-light);
    color: var(--icon-on-light-button); 
    font-size: 1.4rem; 
    margin-top: 1rem; 
    margin-bottom: 1rem; 
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.2s ease-in-out, transform 0.15s ease-in-out;
    width: 70px; 
    height: 70px; 
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1); 
}

#sessionToggleButton:hover:not(:disabled) { /* Only apply hover when not disabled */
    transform: scale(1.08); 
    background-color: var(--accent-hover-light);
}

#sessionToggleButton.active-session {
    background-color: var(--stop-color-light);
}
#sessionToggleButton.active-session:hover:not(:disabled) {
    background-color: var(--stop-hover-light);
}

/* Styles for the loading state */
#sessionToggleButton.loading-state {
    cursor: wait;
}

#sessionToggleButton.loading-state:disabled {
    background-color: var(--accent-color-light);
    color: var(--icon-on-light-button);
    opacity: 0.9; 
    cursor: wait;
    transform: scale(1); 
}

@media (max-width: 600px) {
    h1 {
        font-size: 2rem;
        margin-bottom: 1.5rem; 
    }
    #sessionToggleButton {
        width: 64px;
        height: 64px;
        font-size: 1.3rem;
        margin-top: 0.5rem;
    }
}

#rev-logo-h1 {
    width: 5rem; /* Updated size */
    height: 5rem; /* Updated size */
    margin-right: 0.75rem; /* Original margin */
}

.theme-switch-label {
    position: fixed; 
    top: 1.5rem;    
    right: 1.5rem;   
    z-index: 1000;   
    display: inline-block;
    width: 48px; 
    height: 24px;
    cursor: pointer;
}

#theme-toggle {
    display: none;
}

.slider {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--switch-bg-light);
    border-radius: 24px;
    transition: background-color .4s;
}

.slider::before {
    position: absolute;
    content: "";
    height: 18px; 
    width: 18px;  
    left: 3px;
    bottom: 3px;
    background-color: var(--switch-knob-light);
    border-radius: 50%;
    transition: transform .4s, background-color .4s;
}

#theme-toggle:checked + .slider {
    background-color: var(--switch-active-bg-light);
}

#theme-toggle:checked + .slider::before {
    transform: translateX(24px); 
}

/* Dark Mode Styles */
body.dark-mode {
    background-color: var(--bg-color-dark);
    color: var(--text-color-dark);
}

body.dark-mode h1 {
    color: var(--text-color-dark);
}

body.dark-mode #sessionToggleButton {
    background-color: var(--accent-color-dark);
    color: var(--icon-on-dark-button); 
    box-shadow: 0 4px 10px rgba(0,0,0,0.3); 
}

body.dark-mode #sessionToggleButton.active-session {
    background-color: var(--stop-color-dark);
}

body.dark-mode #sessionToggleButton.loading-state:disabled {
    background-color: var(--accent-color-dark);
    color: var(--icon-on-dark-button);
    opacity: 0.9;
}

body.dark-mode #sessionToggleButton:hover:not(:disabled) {
     background-color: var(--accent-hover-dark);
}
body.dark-mode #sessionToggleButton.active-session:hover:not(:disabled) {
    background-color: var(--stop-hover-dark);
}

body.dark-mode .slider {
    background-color: var(--switch-bg-dark);
}
body.dark-mode .slider::before {
    background-color: var(--switch-knob-dark);
}

body.dark-mode #theme-toggle:checked + .slider {
    background-color: var(--switch-active-bg-dark);
}

#revolt-logo {
    position: fixed;
    top: 1.5rem;
    left: 1.5rem;
    width: 50px;
    height: auto;
    transition: filter 0.3s ease;
}

body.dark-mode #revolt-logo {
    filter: invert(1) brightness(2);
}