@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=JetBrains+Mono&display=swap');

/* --- THEME AND COLOR VARIABLES --- */
:root {
    /* Base Font & Layout */
    --font-primary: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --border-radius: 8px;

    /* Light Theme Palette (Default) */
    --color-primary: #4338ca; 
    --color-primary-hover: #3730a3;
    --color-background: #f4f7f9;
    --color-surface: #ffffff;
    --color-text: #212529;
    --color-text-secondary: #5a6268;
    --color-border: #d1d1d6;
    --color-danger: #dc3545;
    --shadow-color: rgba(0,0,0,0.08);
    --switcher-bg: #e9e9eb;
    --switcher-selection-bg: #ffffff;
    --switcher-selection-shadow: 0 1px 4px rgba(0,0,0,0.12);
}

[data-theme='dark'] {
    /* Dark Theme Palette */
    --color-primary: #6366f1;
    --color-primary-hover: #4f46e5;
    --color-background: #121212;
    --color-surface: #1e1e1e;
    --color-text: #e0e0e0;
    --color-text-secondary: #adb5bd;
    --color-border: #3a3a3c;
    --color-danger: #e57373;
    --shadow-color: rgba(0,0,0,0.25);
    --switcher-bg: #2c2c2e;
    --switcher-selection-bg: #4c4c4e;
    --switcher-selection-shadow: none;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--color-background);
    color: var(--color-text);
    line-height: 1.6;
    padding: 1rem;
    transition: background-color 0.2s, color 0.2s;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px var(--shadow-color);
    border: 1px solid var(--color-border);
    transition: background-color 0.2s, border-color 0.2s;
}

/* --- HEADER & THEME SWITCHER --- */
header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1.5rem;
}

header h1 {
    color: var(--color-primary);
    font-weight: 600;
}

header p {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    margin: 0;
}

.theme-switcher {
    position: relative;
    display: inline-flex;
    background-color: var(--switcher-bg);
    border-radius: 20px;
    padding: 4px;
}

.theme-switcher input {
    appearance: none;
}

.theme-switcher label {
    position: relative;
    z-index: 1;
    padding: 6px 20px;
    border-radius: 16px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    color: var(--color-text-secondary);
    transition: color 0.3s ease;
}

.theme-switcher input:checked + label {
    color: var(--color-text);
}

.theme-switcher-selection {
    position: absolute;
    top: 4px;
    left: 4px;
    width: calc(50% - 4px);
    height: calc(100% - 8px);
    background-color: var(--switcher-selection-bg);
    border-radius: 16px;
    box-shadow: var(--switcher-selection-shadow);
    transition: transform 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.theme-switcher input#dark-theme:checked ~ .theme-switcher-selection {
    transform: translateX(calc(100% + 4px));
}


/* --- TEXTAREA & STATUS --- */
textarea {
    width: 100%;
    height: 300px;
    padding: 1rem;
    font-family: var(--font-mono);
    font-size: 1rem;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    resize: vertical;
    background-color: var(--color-background);
    color: var(--color-text);
    transition: border-color 0.2s, box-shadow 0.2s, background-color 0.2s, color 0.2s;
}

textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 25%, transparent);
}

.status-bar {
    display: flex;
    justify-content: flex-end;
    gap: 1.5rem;
    padding: 0.5rem 0.2rem;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-family: var(--font-mono);
}

/* --- CONTROLS & BUTTONS --- */
.controls {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.button-group {
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: 1rem;
}

.button-group h3 {
    margin-bottom: 1rem;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
}

button {
    font-family: var(--font-primary);
    font-size: 0.9rem;
    padding: 0.6rem 1rem;
    border: 1px solid var(--color-primary);
    background-color: var(--color-primary);
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

button:hover {
    background-color: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    transform: translateY(-1px);
}

button:active {
    transform: translateY(0);
}

.utility-button {
    background-color: var(--color-text-secondary);
    border-color: var(--color-text-secondary);
}

.utility-button:hover {
    background-color: color-mix(in srgb, var(--color-text-secondary) 80%, black);
}

.clear-button {
    background-color: transparent;
    border-color: var(--color-danger);
    color: var(--color-danger);
    margin-left: auto;
}

.clear-button:hover {
    background-color: var(--color-danger);
    color: white;
}

/* --- FOOTER --- */
footer {
    text-align: center;
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}


@media (max-width: 600px) {
    body { padding: 0.5rem; }
    .container { padding: 1rem; }
}