/* Ultra 3D – Thick Curved Borders */

* {
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body {
    margin: 0;
    padding: 1rem;
    background: linear-gradient(135deg, #d0e0ff, #f0f4ff);
    min-height: 100vh;
}

#app {
    max-width: 900px;
    margin: 2rem auto;
    background: #ffffff;
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: 0 30px 60px rgba(0,0,0,0.2),
                0 15px 30px rgba(0,0,0,0.12);
    backdrop-filter: blur(12px);
}

/* ==================== HEADING ==================== */
h1#lesson-title {
    text-align: center;
    font-size: 2.8rem;
    font-weight: 800;
    margin-bottom: 1.8rem;
    background: linear-gradient(180deg, #2c3e50, #1a2533);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 1.2px;
    text-shadow: 
        3px 3px 6px rgba(0,0,0,0.4),
        0 6px 15px rgba(0,0,0,0.25),
        0 0 25px rgba(52, 152, 219, 0.4);
}

#instructions {
    font-size: 1.35rem;
    text-align: center;
    margin: 1.8rem 0;
    color: #2d3436;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-shadow: 
        3px 3px 6px rgba(0,0,0,0.4),
        0 6px 15px rgba(0,0,0,0.25),
        0 0 25px rgba(52, 152, 219, 0.4);
}

#game-container p {
    font-size: 1.6rem;
    margin-bottom: 2rem;
    text-align: center;
    color: #2c3e50;
    font-weight: 600;
    letter-spacing: 0.8px;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.2);
    line-height: 1.5;
}

/* ==================== SUPER 3D BUTTONS – Thick Curved Borders ==================== */
#game-nav {
    display: flex;
    gap: 1.2rem;
    margin-bottom: 2rem;
    justify-content: center;
}

#game-nav button,
.choice,
#restart-lesson-btn {
    position: relative;
    padding: 1.3rem 1.8rem;
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 0.8px;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    overflow: hidden;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.2);
}

/* Base 3D layered border effect */
#game-nav button,
.choice,
#restart-lesson-btn {
    background: linear-gradient(145deg, #ffffff, #e8e8e8);
    box-shadow: 
        0 12px 24px rgba(0,0,0,0.15),
        0 6px 12px rgba(0,0,0,0.1),
        inset 0 -6px 12px rgba(0,0,0,0.05),
        inset 0 6px 12px rgba(255,255,255,0.8);
    border: 4px solid transparent;
    background-clip: padding-box;
}

#game-nav button::before,
.choice::before,
#restart-lesson-btn::before {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 24px;
    padding: 4px;
    background: linear-gradient(145deg, #c0c0c0, #ffffff, #a0a0a0);
    -webkit-mask: 
        linear-gradient(#fff 0 0) padding-box, 
        linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    z-index: -1;
}

#game-nav button:hover,
.choice:hover,
#restart-lesson-btn:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 
        0 20px 40px rgba(0,0,0,0.25),
        0 10px 20px rgba(0,0,0,0.15);
}

/* Active game button – highlighted in primary blue */
#game-nav button.active {
    background: linear-gradient(145deg, #007bff, #0056b3) !important;
    color: white !important;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.4);
    box-shadow: 
        0 12px 24px rgba(0,123,255,0.4),
        0 6px 12px rgba(0,0,0,0.2),
        inset 0 6px 12px rgba(255,255,255,0.3);
    transform: translateY(-4px);
}

#game-nav button.active::before {
    background: linear-gradient(145deg, #0069d9, #0095ff, #004085);
}

#game-nav button.active:hover {
    transform: translateY(-8px);
    box-shadow: 
        0 20px 40px rgba(0,123,255,0.5),
        0 10px 20px rgba(0,0,0,0.25);
}

/* Specific overrides */
#game-nav button {
    flex: 1;
    max-width: 280px;
    color: #2c3e50;
}

/* Completed game button – Green highlight */
#game-nav button.completed {
    background: linear-gradient(145deg, #28a745, #218838) !important;
    color: white !important;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
    box-shadow: 
        0 12px 24px rgba(40,167,69,0.4),
        0 6px 12px rgba(0,0,0,0.2),
        inset 0 6px 12px rgba(255,255,255,0.3);
    transform: translateY(-4px);
}

#game-nav button.completed::before {
    background: linear-gradient(145deg, #218838, #34ce57, #1e7e34);
}

#game-nav button.completed:hover {
    transform: translateY(-8px);
    box-shadow: 
        0 20px 40px rgba(40,167,69,0.5),
        0 10px 20px rgba(0,0,0,0.25);
}

/* When a button is both active AND completed, blue takes priority */
#game-nav button.active.completed {
    background: linear-gradient(145deg, #007bff, #0056b3) !important;
}

#game-nav button.active.completed::before {
    background: linear-gradient(145deg, #0069d9, #0095ff, #004085);
}

#game-nav button.completed {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

/* Fully disable hover effects on disabled nav buttons */
#game-nav button:disabled {
    cursor: not-allowed;
    opacity: 0.75; /* Visual cue that it's disabled */
    transform: none !important;
    box-shadow: 
        0 12px 24px rgba(0,0,0,0.15),
        0 6px 12px rgba(0,0,0,0.1),
        inset 0 -6px 12px rgba(0,0,0,0.05),
        inset 0 6px 12px rgba(255,255,255,0.8) !important; /* Lock the base inner highlight */
}

#game-nav button:disabled:hover {
    transform: none !important;
    box-shadow: 
        0 12px 24px rgba(0,0,0,0.15),
        0 6px 12px rgba(0,0,0,0.1),
        inset 0 -6px 12px rgba(0,0,0,0.05),
        inset 0 6px 12px rgba(255,255,255,0.8) !important; /* Exactly the same as non-hover */
}

.choice {
    margin: 1.2rem 0;
    background: linear-gradient(145deg, #ffffff, #f0f0f0);
    color: #2d3436;
    font-size: 1.45rem;
}

.choice.selected {
    background: linear-gradient(145deg, #b8dcff, #90c8ff);
    box-shadow: 
        inset 0 10px 20px rgba(100,180,255,0.3),
        inset 0 -8px 16px rgba(255,255,255,0.7);
    color: #1e40af;
}

/* Restart button – primary color */
#restart-lesson-btn {
    background: linear-gradient(145deg, #007bff, #0056b3);
    color: white;
    padding: 1.4rem 3rem;
    font-size: 1.35rem;
}

#restart-lesson-btn::before {
    background: linear-gradient(145deg, #0069d9, #0095ff, #004085);
}

/* ==================== FEEDBACK / RESULTS – 3D Treatment ==================== */
#feedback {
    margin-top: 2.5rem;
    font-size: 1.9rem;
    font-weight: 800;
    text-align: center;
    padding: 1.8rem;
    border-radius: 20px;
    min-height: 80px;
    letter-spacing: 1.2px;
    position: relative;
    overflow: hidden;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    background: linear-gradient(145deg, #f8f9fc, #e9ecef);
    box-shadow: 
        0 12px 24px rgba(0,0,0,0.12),
        inset 0 8px 16px rgba(255,255,255,0.8),
        inset 0 -8px 16px rgba(0,0,0,0.05);
    border: 4px solid transparent;
    background-clip: padding-box;
}

#feedback::before {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: 24px;
    padding: 4px;
    background: linear-gradient(145deg, #bbbbbb, #ffffff, #999999);
    -webkit-mask: 
        linear-gradient(#fff 0 0) padding-box, 
        linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    z-index: -1;
}

.correct {
    color: #1e7b4a;
    background: linear-gradient(145deg, rgba(39,174,96,0.15), rgba(20,120,60,0.1));
    box-shadow: 
        0 15px 30px rgba(39,174,96,0.3),
        inset 0 10px 20px rgba(255,255,255,0.6);
    text-shadow: 0 0 15px rgba(39,174,96,0.6);
}

.incorrect {
    color: #c0392b;
    background: linear-gradient(145deg, rgba(231,76,60,0.15), rgba(180,40,40,0.1));
    box-shadow: 
        0 15px 30px rgba(231,76,60,0.3),
        inset 0 10px 20px rgba(255,255,255,0.5);
    text-shadow: 0 0 15px rgba(231,76,60,0.5);
}

/* Match game columns */
#bg-column, #en-column {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

#restart-lesson-container {
    text-align: center;
    margin-top: 2.5rem;
}

/* Fade-in */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

#app > * {
    animation: fadeIn 0.7s ease-out forwards;
}

/* Make choice buttons shorter and more compact */
.choice {
    padding: 0.8rem 1.2rem !important;   /* Reduced vertical padding */
    margin: 0.4rem 0 !important;         /* Less vertical margin */
    line-height: 1.4 !important;         /* Tighter line height */
    min-height: auto !important;         /* Prevent fixed minimum height */
}

/* Reduce spacing in match game columns */
#bg-column, #en-column {
    gap: 0.6rem !important;              /* Smaller gap between items */
}

/* Reduce spacing around prompt/sentence text */
#game-container > p {
    margin: 1rem 0 !important;
    line-height: 1.5 !important;
}

/* Overall tighter layout for game container */
#game-container {
    gap: 0.8rem;                         /* Consistent reduced spacing */
}

#resources {
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 2px solid #e0e7ff;
    color: #636e72;
    font-size: 1.1rem;
}

.resource-link {
    color: #007bff;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.resource-link:hover {
    color: #0056b3;
    text-decoration: underline;
}

@media (max-width: 640px) {
    /* Reduce base font size for the whole app on mobile */
    html {
        font-size: 14px;  /* Down from browser default ~16px */
    }

    /* Title – scales down significantly */
    h1#lesson-title {
        font-size: 1.8rem;  /* Was 2.8rem → ~64% smaller */
    }

    /* Instructions and prompts */
    #instructions,
    #game-container p {
        font-size: 1.1rem;  /* Was 1.35rem / 1.6rem */
    }

    /* Nav buttons (Match, Conversation, Fill in the Blank) */
    #game-nav button {
        padding: 0.8rem 1rem;     /* Was 1.3rem 1.8rem → much smaller */
        font-size: 1rem;          /* Was 1.2rem */
        max-width: 220px;         /* Slightly smaller to fit better */
    }

    /* Choice buttons in games */
    .choice {
        padding: 0.6rem 0.9rem !important;  /* Was 0.8rem 1.2rem → tighter */
        font-size: 1.15rem;                 /* Was 1.45rem */
        margin: 0.3rem 0 !important;
    }

    /* Feedback text */
    #feedback {
        font-size: 1.4rem;        /* Was 1.9rem */
        padding: 1.2rem;
    }

    /* Restart button */
    #restart-lesson-btn {
        padding: 1rem 2rem;       /* Was 1.4rem 3rem */
        font-size: 1.1rem;        /* Was 1.35rem */
    }

    /* Tighter gaps in match game columns */
    #bg-column, #en-column {
        gap: 0.4rem !important;
    }

    /* Optional: Stack nav buttons vertically on very small screens for better fit */
    #game-nav {
        flex-direction: column;
        align-items: center;
        gap: 0.8rem;
    }

    /* Reduce overall app padding on mobile */
    #app {
        padding: 1.5rem;
        margin: 1rem auto;
    }
}