:root {
    --font-sans: "Inter", ui-sans-serif, system-ui, sans-serif;
    --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, monospace;
    --color-bg: #f5fbff;
    --color-ink: #0f394c;
    --color-accent: #49b5e7;
    --color-paper: #ffffff;
    --color-blue: #49b5e7;
    --color-blue-active: #82d1f5;
    --color-red: #ff5e5e;
    --color-red-active: #ff8a8a;
    --color-green: #4ade80;
    --color-green-active: #86efac;
    --color-yellow: #facc15;
    --color-yellow-active: #fde047;
    --header-height: auto;
    --footer-height: 4rem;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    background-color: var(--color-bg);
    color: var(--color-ink);
    font-family: var(--font-sans);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    justify-content: center;
    overflow-x: hidden;
}

.app-container {
    width: 100%;
    max-width: 1000px;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    min-height: 100dvh;
    position: relative;
}

/* Header Styles */
.game-header {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    gap: 1rem;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 3rem;
    height: 3rem;
    background-color: var(--color-ink);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    transform: rotate(-6deg);
}

.icon-paper { color: var(--color-paper); width: 1.75rem; height: 1.75rem; }
.icon-accent { color: var(--color-accent); width: 0.75rem; height: 0.75rem; }

.logo-text h1 {
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
}

.logo-text p {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    opacity: 0.5;
}

.stats-section {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.icon-btn {
    padding: 0.75rem;
    background-color: var(--color-paper);
    border-radius: 0.75rem;
    border: 1px solid rgba(15, 57, 76, 0.05);
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    color: rgba(15, 57, 76, 0.6);
    cursor: pointer;
    transition: all 0.2s;
}

.icon-btn:hover { color: var(--color-ink); }
.icon-btn svg { width: 1.25rem; height: 1.25rem; }

.high-score-card {
    background-color: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(4px);
    padding: 0.5rem 1rem;
    border-radius: 1rem;
    border: 1px solid rgba(15, 57, 76, 0.05);
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.score-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.score-label span {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    opacity: 0.4;
}

.score-value {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 1rem;
}

/* Main Content Styles */
.game-main {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    width: 100%;
}

.game-board-container {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
    margin-top: 1rem;
}

.status-message-container {
    position: absolute;
    top: -3.5rem;
    left: 0;
    right: 0;
    text-align: center;
}

#message {
    font-size: 1.25rem;
    font-weight: 700;
    color: rgba(15, 57, 76, 0.8);
    transition: all 0.2s;
}

/* Simon Board Responsiveness */
.simon-board {
    position: relative;
    width: 90vw;
    height: 90vw;
    max-width: 400px;
    max-height: 400px;
    background-color: var(--color-paper);
    border-radius: 3rem;
    padding: 1rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    gap: 1rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    border: 1px solid rgba(15, 57, 76, 0.05);
}

.color-btn {
    border-radius: 2rem;
    border: 4px solid transparent;
    cursor: default;
    transition: all 0.2s;
    opacity: 0.8;
    position: relative;
    overflow: hidden;
}

.color-btn.cursor-pointer { cursor: pointer; }
.color-btn.cursor-pointer:hover { transform: scale(1.02); }
.color-btn.cursor-pointer:active { transform: scale(0.92); }

.color-btn.blue { background-color: var(--color-blue); border-color: rgba(73, 181, 231, 0.2); }
.color-btn.red { background-color: var(--color-red); border-color: rgba(255, 94, 94, 0.2); }
.color-btn.green { background-color: var(--color-green); border-color: rgba(74, 222, 128, 0.2); }
.color-btn.yellow { background-color: var(--color-yellow); border-color: rgba(250, 204, 21, 0.2); }

.color-btn.active {
    opacity: 1;
    transform: scale(1.05);
}

.color-btn.active.blue { background-color: var(--color-blue-active); box-shadow: 0 0 40px rgba(73, 181, 231, 0.5); }
.color-btn.active.red { background-color: var(--color-red-active); box-shadow: 0 0 40px rgba(255, 94, 94, 0.5); }
.color-btn.active.green { background-color: var(--color-green-active); box-shadow: 0 0 40px rgba(74, 222, 128, 0.5); }
.color-btn.active.yellow { background-color: var(--color-yellow-active); box-shadow: 0 0 40px rgba(250, 204, 21, 0.5); }

.color-btn.active::after {
    content: '';
    position: absolute;
    inset: 0;
    background-color: rgba(255, 255, 255, 0.3);
    z-index: 10;
    animation: fadeIn 0.2s ease-out forwards;
}

.center-score {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 6.5rem;
    height: 6.5rem;
    background-color: var(--color-paper);
    border-radius: 50%;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border: 6px solid var(--color-bg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 20;
}

.center-label {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    opacity: 0.4;
    margin-bottom: 0.1rem;
}

.center-value {
    font-family: var(--font-mono);
    font-size: 2rem;
    font-weight: 700;
}

/* Controls Styles */
.game-controls {
    width: 100%;
    max-width: 320px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.difficulty-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.diff-btn-container {
    display: flex;
    padding: 0.25rem;
    background-color: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(4px);
    border-radius: 1rem;
    border: 1px solid rgba(15, 57, 76, 0.05);
}

.diff-btn {
    flex: 1;
    padding: 0.5rem;
    border-radius: 0.75rem;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: rgba(15, 57, 76, 0.4);
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    background: none;
}

.diff-btn.active {
    background-color: var(--color-ink);
    color: var(--color-paper);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.primary-btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--color-ink);
    color: var(--color-paper);
    border-radius: 1rem;
    font-size: 1.125rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.primary-btn:hover { background-color: var(--color-accent); }
.primary-btn:active { transform: scale(0.98); }

.secondary-btn {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--color-paper);
    border: 1px solid rgba(15, 57, 76, 0.05);
    border-radius: 1rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

.secondary-btn:hover { background-color: var(--color-ink); color: var(--color-paper); }

/* Footer Styles */
.game-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
    color: rgba(15, 57, 76, 0.4);
}

.footer-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.help-trigger {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: help;
    position: relative;
}

.help-tooltip {
    position: absolute;
    bottom: 100%;
    right: 0;
    margin-bottom: 1rem;
    width: 250px;
    padding: 1.25rem;
    background-color: var(--color-ink);
    color: var(--color-paper);
    border-radius: 1.25rem;
    font-size: 0.75rem;
    line-height: 1.5;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
    z-index: 50;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    pointer-events: none;
}

.group:hover .help-tooltip {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.help-details {
    margin-top: 0.75rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 0.75rem;
}

/* Animations & Utils */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes popIn { 
    0% { transform: scale(0.8); opacity: 0; }
    70% { transform: scale(1.05); }
    100% { transform: scale(1); opacity: 1; }
}

.animate-message { animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards; }
.hidden { display: none; }
.fill-current { fill: currentColor; }

/* Desktop Adjustments */
@media (min-width: 768px) {
    .app-container { padding: 2rem; }
    .simon-board { max-width: 480px; max-height: 480px; padding: 1.5rem; gap: 1.5rem; border-radius: 4rem; }
    .color-btn { border-radius: 2.5rem; }
    .center-score { width: 8rem; height: 8rem; border-width: 10px; }
    .center-value { font-size: 2.5rem; }
    .logo-text h1 { font-size: 1.75rem; }
    .status-message-container { top: -4.5rem; }
    #message { font-size: 1.5rem; }
}

@media (max-width: 350px) {
    .logo-text p, .score-label span { display: none; }
    .simon-board { padding: 0.75rem; gap: 0.75rem; }
}