/* 1. Theme ke colors */
:root {
    --bg-color: #0b1220;
    --card-color: #111c2e;
    --teal-color: #2dd4bf;
    --text-color: #f8fafc;
    --muted-color: #94a3b8;
    --border-color: #263449;
    --success-color: #34d399;
}

/* 2. Har element ki sizing */
* {
    box-sizing: border-box;
}

/* 3. Page ki basic styling */
html {
    min-height: 100%;
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

body {
    margin: 0;
    min-height: 100vh;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: radial-gradient(circle at top, #14243a, var(--bg-color) 65%);
    color: var(--text-color);
    line-height: 1.5;
}

/* 4. Main container */
.container {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    padding: 32px 20px;
}

/* 5. Heading section */
.header {
    text-align: center;
    margin-bottom: 28px;
}

.logo {
    font-size: 48px;
    margin-bottom: 10px;
}

h1 {
    margin: 0;
    font-size: clamp(30px, 5vw, 46px);
    line-height: 1.2;
    letter-spacing: -1px;
}

.highlight {
    color: var(--teal-color);
}

.subtitle {
    max-width: 500px;
    margin: 14px auto 0;
    color: var(--muted-color);
    font-size: 16px;
}

/* 6. Start screen */
.start-screen {
    max-width: 520px;
    margin: 0 auto 24px;
    padding: 32px 20px;
    text-align: center;
    background: var(--card-color);
    border: 1px solid var(--border-color);
    border-radius: 20px;
}

.start-emoji {
    font-size: 48px;
}

.start-screen h2 {
    margin: 12px 0 8px;
    font-size: 25px;
}

.start-screen p {
    margin: 0 0 22px;
    color: var(--muted-color);
}

/* 7. Buttons */
.main-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border: none;
    border-radius: 12px;
    background: var(--teal-color);
    color: #06231f;
    font-family: inherit;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    touch-action: manipulation;
    transition: background 0.2s ease, transform 0.2s ease;
}

.main-button:hover {
    background: #5eead4;
    transform: translateY(-1px);
}

.main-button:active {
    transform: translateY(0);
}

.main-button:focus-visible {
    outline: 3px solid var(--text-color);
    outline-offset: 3px;
}

/* Hidden attribute ko har haal mein apply karna */
[hidden] {
    display: none !important;
}

/* 8. Game statistics */
.stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    margin-bottom: 22px;
}

.stat-box {
    min-width: 0;
    padding: 17px 10px;
    text-align: center;
    background: var(--card-color);
    border: 1px solid var(--border-color);
    border-radius: 15px;
}

.stat-label {
    display: block;
    margin-bottom: 7px;
    color: var(--muted-color);
    font-size: 12px;
    font-weight: bold;
    letter-spacing: 1px;
}

.stat-value {
    display: block;
    font-size: clamp(20px, 3vw, 28px);
    font-weight: bold;
    font-variant-numeric: tabular-nums;
}

/* 9. Cards ka board */
.game-board {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
    width: 100%;
    margin: 0 auto 24px;
}

/* 10. Individual cards */
.memory-card {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-width: 0;
    aspect-ratio: 1 / 1;
    padding: 0;
    overflow: hidden;
    border: 1px solid #30445d;
    border-radius: 15px;
    background: linear-gradient(145deg, #17283d, #111c2e);
    color: var(--text-color);
    font-family: inherit;
    font-size: clamp(25px, 5vw, 42px);
    cursor: pointer;
    user-select: none;
    touch-action: manipulation;
    transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

@media (hover: hover) {
    .memory-card:hover:not(:disabled) {
        transform: translateY(-3px);
        border-color: var(--teal-color);
    }
}

.memory-card.flipped {
    background: #173847;
    border-color: var(--teal-color);
}

.memory-card.matched {
    background: #123b36;
    border-color: var(--success-color);
    cursor: default;
}

.memory-card:focus-visible {
    outline: 3px solid var(--teal-color);
    outline-offset: 2px;
}

.memory-card:disabled {
    opacity: 1;
    cursor: default;
}

/* 11. Restart button */
.controls {
    display: flex;
    justify-content: center;
    margin: 0 0 18px;
}

#restartButton {
    min-width: 190px;
}

/* 12. Messages */
.message {
    min-height: 48px;
    margin: 0 0 20px;
    padding: 10px 8px;
    color: var(--teal-color);
    text-align: center;
    font-size: 15px;
    font-weight: bold;
    overflow-wrap: anywhere;
}

/* 13. Instructions */
.instructions {
    padding: 22px 24px;
    background: var(--card-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    color: var(--muted-color);
    font-size: 14px;
    line-height: 1.8;
}

.instructions h2 {
    margin: 0 0 12px;
    color: var(--text-color);
    font-size: 19px;
}

.instructions ol {
    margin: 0;
    padding-left: 22px;
}

.instructions li {
    margin-bottom: 5px;
}

/* 14. Footer */
.footer {
    margin-top: 26px;
    padding: 12px 0;
    color: var(--muted-color);
    text-align: center;
    font-size: 12px;
}

/* 15. Tablet screens */
@media (max-width: 700px) {
    .container {
        max-width: 560px;
        padding: 25px 18px;
    }

    .header {
        margin-bottom: 23px;
    }

    .stats {
        gap: 10px;
    }

    .stat-box {
        padding: 14px 7px;
    }

    .game-board {
        gap: 11px;
    }

    .memory-card {
        border-radius: 12px;
    }

    .instructions {
        padding: 18px;
    }
}

/* 16. Mobile screens */
@media (max-width: 420px) {
    .container {
        padding: 22px 12px;
    }

    .logo {
        font-size: 40px;
    }

    h1 {
        font-size: clamp(27px, 8vw, 34px);
    }

    .subtitle {
        font-size: 14px;
    }

    .start-screen {
        padding: 25px 15px;
    }

    .start-screen h2 {
        font-size: 22px;
    }

    .start-screen p {
        font-size: 14px;
    }

    .stats {
        gap: 7px;
    }

    .stat-box {
        padding: 12px 4px;
        border-radius: 11px;
    }

    .stat-label {
        font-size: 10px;
        letter-spacing: 0.4px;
    }

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

    .game-board {
        gap: 8px;
    }

    .memory-card {
        border-radius: 10px;
        font-size: clamp(23px, 8vw, 32px);
    }

    .main-button {
        width: 100%;
        max-width: 280px;
    }

    .message {
        font-size: 13px;
    }

    .instructions {
        padding: 16px;
        font-size: 13px;
    }
}

/* 17. Bohat chhoti screens */
@media (max-width: 340px) {
    .container {
        padding-right: 9px;
        padding-left: 9px;
    }

    .game-board {
        gap: 6px;
    }

    .stats {
        gap: 5px;
    }

    .stat-label {
        font-size: 9px;
    }

    .stat-value {
        font-size: 18px;
    }

    .memory-card {
        font-size: 22px;
    }

    .instructions {
        padding: 13px;
    }
}

/* 18. Motion kam karne ki accessibility setting */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        transition: none !important;
        animation: none !important;
    }
}