/* Reset và cài đặt cơ bản */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: #0d1117;
    color: #c9d1d9;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    max-width: 900px;
    width: 100%;
    background-color: #161b22;
    border-radius: 16px;
    padding: 30px 35px 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
    border: 1px solid #30363d;
}

/* Header */
header {
    margin-bottom: 24px;
    text-align: center;
}

header h1 {
    font-size: 28px;
    font-weight: 700;
    color: #f0f6fc;
    letter-spacing: -0.5px;
}

header p {
    color: #8b949e;
    font-size: 15px;
    margin-top: 6px;
}

/* Editor */
.editor-wrapper {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

textarea {
    width: 100%;
    min-height: 260px;
    padding: 16px 18px;
    font-size: 16px;
    line-height: 1.7;
    font-family: inherit;
    background-color: #0d1117;
    color: #e6edf3;
    border: 1px solid #30363d;
    border-radius: 12px;
    resize: vertical;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

textarea:focus {
    border-color: #58a6ff;
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
}

textarea::placeholder {
    color: #484f58;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 12px;
    background-color: #0d1117;
    border-radius: 12px;
    padding: 18px 14px;
    border: 1px solid #21262d;
}

.stat-item {
    text-align: center;
    padding: 6px 4px;
}

.stat-value {
    display: block;
    font-size: 26px;
    font-weight: 700;
    color: #f0f6fc;
    line-height: 1.2;
    transition: color 0.2s ease;
}

.stat-label {
    display: block;
    font-size: 13px;
    color: #8b949e;
    margin-top: 4px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

/* Footer */
footer {
    margin-top: 24px;
    text-align: center;
    font-size: 13px;
    color: #484f58;
    border-top: 1px solid #21262d;
    padding-top: 16px;
}

/* Responsive */
@media (max-width: 700px) {
    .container {
        padding: 20px 16px;
    }

    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
        padding: 14px 10px;
    }

    .stat-value {
        font-size: 22px;
    }

    .stat-label {
        font-size: 11px;
    }

    header h1 {
        font-size: 22px;
    }

    textarea {
        min-height: 180px;
        font-size: 15px;
        padding: 12px 14px;
    }
}

@media (max-width: 420px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .stat-value {
        font-size: 20px;
    }
}