:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --border-color: #334155;
    --font-main: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 2rem;
}

.app-container {
    width: 100%;
    max-width: 1200px;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

header {
    text-align: center;
    margin-bottom: 1rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--accent-color), #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-secondary);
}

.input-section textarea {
    width: 100%;
    height: 150px;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 1rem;
    resize: vertical;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    outline: none;
}

.input-section textarea:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(50px, 1fr));
    gap: 0.75rem;
    padding: 1rem 0;
}

.char-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    aspect-ratio: 1;
    position: relative;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    animation: fadeIn 0.3s ease-out forwards;
}

.char-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 10px -2px rgba(0, 0, 0, 0.3);
    border-color: var(--accent-color);
}

.char-card.special-char {
    background-color: #ea580c;
    /* Orange */
    border-color: #c2410c;
}

.char-card.special-char .char-display,
.char-card.special-char .char-position {
    color: #fff;
}

.char-card.special-char .char-code-point {
    background-color: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.char-card.special-char .char-utf8 {
    color: rgba(255, 255, 255, 0.8);
}

.char-card.multi-byte-char {
    background-color: #c084fc;
    /* Light Purple */
    border-color: #a855f7;
}

.char-card.multi-byte-char .char-display,
.char-card.multi-byte-char .char-position {
    color: #fff;
}

.char-card.multi-byte-char .char-code-point {
    background-color: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.char-card.multi-byte-char .char-utf8 {
    color: rgba(255, 255, 255, 0.8);
}

.char-position {
    position: absolute;
    top: 4px;
    left: 6px;
    font-size: 0.65rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.char-display {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 0.25rem;
}

.char-meta {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    margin-bottom: 4px;
}

.char-code-point,
.char-utf8 {
    font-size: 0.6rem;
    font-family: var(--font-mono);
    padding: 1px 4px;
    border-radius: 3px;
}

.char-code-point {
    color: var(--accent-color);
    background-color: rgba(56, 189, 248, 0.1);
}

.char-utf8 {
    color: var(--text-secondary);
    font-size: 0.55rem;
}

.byte-counter {
    position: absolute;
    bottom: 4px;
    right: 6px;
    font-size: 0.6rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
    opacity: 0.7;
}

.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    color: var(--text-secondary);
    padding: 3rem;
    font-style: italic;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}