:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --border-color: rgba(255, 255, 255, 0.1);
    --success: #22c55e;
    --error: #ef4444;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    padding: 2rem;
}

#app-container {
    max-width: 1000px;
    margin: 0 auto;
}

header {
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

.subtitle {
    color: var(--text-secondary);
}

main {
    display: grid;
    gap: 2rem;
}

.input-section {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    display: grid;
    gap: 1.5rem;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-weight: 500;
    color: var(--accent-color);
}

input[type="text"],
input[type="number"] {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
}

input[type="text"]:focus,
input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-color);
}

select {
    appearance: none;
    background-color: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    width: 100%;
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2338bdf8'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1em;
}

select:focus {
    outline: none;
    border-color: var(--accent-color);
}

select option {
    background-color: #1e293b;
    color: var(--text-primary);
}

.help-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
    font-size: 1rem;
}

.btn.primary {
    background: var(--accent-color);
    color: #0f172a;
}

.btn.primary:hover {
    background: var(--accent-hover);
}

#results-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

#results-section.hidden {
    display: none;
}

.result-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.result-card.full-width {
    grid-column: 1 / -1;
}

h3 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.highlight {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
}

.scroll-box {
    max-height: 200px;
    overflow-y: auto;
    background: rgba(15, 23, 42, 0.4);
    padding: 1rem;
    border-radius: 8px;
    font-family: monospace;
    line-height: 1.5;
}

.table-container {
    overflow-x: auto;
}

table {
    border-collapse: collapse;
    width: 100%;
    font-size: 0.9rem;
}

#word-problem-result {
    font-family: 'Fira Code', monospace;
    white-space: pre-wrap;
    line-height: 1.5;
}

th,
td {
    padding: 8px;
    text-align: center;
    border: 1px solid var(--border-color);
}

th {
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-color);
}

td {
    background: rgba(30, 41, 59, 0.5);
}

.status-bar {
    grid-column: 1 / -1;
    padding: 1rem;
    border-radius: 8px;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
}

.error-msg {
    color: var(--error);
}

/* Back/breadcrumb link */
.back-link {
    display: inline-block;
    color: #60a5fa;
    text-decoration: none;
    font-size: 0.85rem;
    opacity: 0.7;
    transition: opacity 0.2s;
    margin-bottom: 8px;
}
.back-link:hover { opacity: 1; }

@keyframes slowPulse {
    0% { opacity: 1; }
    50% { opacity: 0.4; }
    100% { opacity: 1; }
}

.pulsing {
    animation: slowPulse 1.5s ease-in-out infinite;
}


/* === Accessibility === */
:focus-visible {
    outline: 3px solid var(--accent-color, #38bdf8);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}