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

:root {
    --bg-color: #1a1a2e;
    --tile-bg: #121213;
    --tile-border: #3a3a3c;
    --tile-active: #565758;
    --green: #538d4e;
    --yellow: #b59f3b;
    --grey: #3a3a3c;
    --text-color: #ffffff;
    --key-bg: #818384;
    --key-hover: #565758;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Clear Sans', 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Header */
header {
    padding: 1rem;
    border-bottom: 1px solid var(--tile-border);
    width: 100%;
    text-align: center;
}

header h1 {
    font-size: 1.8rem;
    font-weight: 700;
}

/* Tab Bar */
.tab-bar {
    display: flex;
    gap: 0.5rem;
    padding: 1rem;
    border-bottom: 1px solid var(--tile-border);
}

.tab-btn {
    background: transparent;
    border: 1px solid var(--tile-border);
    color: var(--text-color);
    padding: 0.5rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.2s;
}

.tab-btn:hover {
    border-color: var(--key-hover);
}

.tab-btn.active {
    background: var(--key-bg);
    border-color: var(--key-bg);
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1rem;
    width: 100%;
    max-width: 500px;
}

.tab-content {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: center;
}

.tab-content.active {
    display: flex;
}

/* Grid */
.grid {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin-bottom: 1rem;
}

.grid-row {
    display: flex;
    gap: 5px;
    justify-content: center;
}

.tile {
    width: 62px;
    height: 62px;
    border: 2px solid var(--tile-border);
    background-color: transparent;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2rem;
    font-weight: 700;
    text-transform: uppercase;
    transition: transform 0.25s;
    backface-visibility: hidden;
}

.tile[data-state='active'] {
    border-color: var(--tile-active);
    animation: pop 0.1s;
}

.tile[data-state='correct'] {
    background-color: var(--green);
    border-color: var(--green);
}

.tile[data-state='present'] {
    background-color: var(--yellow);
    border-color: var(--yellow);
}

.tile[data-state='absent'] {
    background-color: var(--grey);
    border-color: var(--grey);
}

.tile.flip {
    animation: flip 0.5s ease-in;
}

@keyframes flip {
    0% { transform: rotateX(0); }
    50% { transform: rotateX(90deg); }
    100% { transform: rotateX(0); }
}

@keyframes pop {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

.grid-row.shake {
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

.grid-row.bounce {
    animation: bounce 0.5s;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    25% { transform: translateY(-10px); }
    50% { transform: translateY(0); }
    75% { transform: translateY(-10px); }
}

/* Keyboard */
.keyboard {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: 100%;
    max-width: 500px;
}

.keyboard-row {
    display: flex;
    justify-content: center;
    gap: 6px;
}

.key {
    height: 58px;
    min-width: 43px;
    padding: 0 12px;
    background-color: var(--key-bg);
    border: none;
    border-radius: 4px;
    color: var(--text-color);
    font-size: 1.2rem;
    font-weight: 700;
    text-transform: uppercase;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.1s;
}

.key:hover {
    background-color: var(--key-hover);
}

.key:active {
    transform: scale(0.95);
}

.key.large {
    min-width: 65px;
    font-size: 0.9rem;
}

.key[data-state='correct'] {
    background-color: var(--green);
}

.key[data-state='present'] {
    background-color: var(--yellow);
}

.key[data-state='absent'] {
    background-color: var(--tile-border);
    opacity: 0.5;
}

/* Message */
.message {
    min-height: 2rem;
    margin-top: 1rem;
    font-weight: 600;
    text-align: center;
}

/* AI Solve */
.ai-controls {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.ai-controls input {
    padding: 0.5rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--tile-border);
    border-radius: 4px;
    background: var(--tile-bg);
    color: var(--text-color);
    text-transform: uppercase;
    text-align: center;
    width: 120px;
}

.ai-controls button {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    border: 1px solid var(--tile-border);
    border-radius: 4px;
    background: var(--key-bg);
    color: var(--text-color);
    cursor: pointer;
    font-weight: 600;
}

.ai-controls button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.ai-controls button:not(:disabled):hover {
    background: var(--key-hover);
}

.ai-status {
    margin-bottom: 1rem;
    font-weight: 600;
    text-align: center;
    min-height: 1.5rem;
}

/* Stats */
.stats-summary {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    width: 100%;
    margin-bottom: 2rem;
}

.stat-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1rem;
    background: var(--tile-bg);
    border-radius: 8px;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.8rem;
    opacity: 0.8;
    margin-top: 0.25rem;
}

.distribution-bars {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    width: 100%;
    margin-bottom: 2rem;
}

.dist-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dist-label {
    width: 20px;
    font-weight: 600;
}

.dist-bar-container {
    flex: 1;
    height: 24px;
    background: var(--tile-bg);
    border-radius: 4px;
    overflow: hidden;
}

.dist-bar {
    height: 100%;
    background: var(--green);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 0.5rem;
    font-weight: 600;
    min-width: 2rem;
    transition: width 0.3s;
}

.dist-count {
    width: 30px;
    text-align: right;
    font-weight: 600;
}

.reset-btn {
    padding: 0.75rem 1.5rem;
    background: transparent;
    border: 1px solid var(--tile-border);
    color: var(--text-color);
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
}

.reset-btn:hover {
    background: var(--tile-bg);
}

/* Footer */
footer {
    padding: 1rem;
    border-top: 1px solid var(--tile-border);
    width: 100%;
    text-align: center;
    display: flex;
    justify-content: center;
    gap: 1rem;
    align-items: center;
}

footer a {
    color: var(--text-color);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 400px) {
    .tile {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }

    .key {
        height: 50px;
        min-width: 35px;
        padding: 0 8px;
        font-size: 1rem;
    }

    .key.large {
        min-width: 55px;
    }

    .stats-summary {
        grid-template-columns: repeat(2, 1fr);
    }
}

.action-btn {
    display: block;
    margin: 16px auto;
    padding: 10px 24px;
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    background: #538d4e;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s;
}
.action-btn:disabled {
    background: #3a3a3c;
    cursor: default;
}
.action-btn:hover:not(:disabled) {
    background: #6abf5e;
}