/* ═══════════════════════════════════════════════════════════
   Scientific Calculator Styles - Dark/Light Compatible
   ═══════════════════════════════════════════════════════════ */

.calculator-card {
    max-width: 850px;
    margin: 30px auto;
    padding: 25px;
    background: var(--bg-card, #ffffff);
    border: 1px solid var(--border, #e2e8f0);
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05);
}

.page-title {
    text-align: center;
    font-size: 2rem;
    color: var(--text-heading, #0f172a);
    margin-bottom: 6px;
}

.page-subtitle {
    text-align: center;
    color: var(--text-muted, #64748b);
    font-size: 0.95rem;
    margin-bottom: 25px;
}

/* Calculator Container */
.sci-calc {
    background-color: var(--bg-input, #f8fafc);
    border: 1px solid var(--border, #cbd5e1);
    border-radius: 12px;
    padding: 20px;
}

/* Screen Section */
.calc-screen {
    background: #0f172a;
    border-radius: 10px;
    padding: 15px 20px;
    margin-bottom: 15px;
    color: #f8fafc;
    text-align: right;
    border: 1px solid #334155;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.4);
}

.calc-history {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: #94a3b8;
    min-height: 20px;
    overflow-x: auto;
    white-space: nowrap;
}

.calc-display-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-top: 5px;
}

.mode-indicator {
    font-size: 0.75rem;
    font-weight: 700;
    background: #1e293b;
    color: #38bdf8;
    padding: 3px 8px;
    border-radius: 4px;
    border: 1px solid #334155;
}

.calc-input {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: #f8fafc;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.8rem;
    text-align: right;
    font-weight: 600;
}

/* Control Mode Bar */
.calc-mode-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding: 0 4px;
}

.unit-toggle {
    display: flex;
    background: var(--bg-card, #ffffff);
    border: 1px solid var(--border, #cbd5e1);
    border-radius: 6px;
    overflow: hidden;
}

.btn-toggle {
    background: transparent;
    border: none;
    padding: 6px 14px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted, #64748b);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-toggle.active {
    background: var(--accent, #2563eb);
    color: #ffffff;
}

.memory-indicators {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent, #2563eb);
}

/* Grid Layout */
.calc-keypad {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 8px;
}

/* Button Base Styles */
.btn {
    padding: 14px 6px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 8px;
    border: 1px solid var(--border, #cbd5e1);
    cursor: pointer;
    transition: all 0.15s ease-in-out;
    user-select: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn:active {
    transform: scale(0.96);
}

.btn-num {
    background-color: var(--bg-card, #ffffff);
    color: var(--text-heading, #0f172a);
}

.btn-num:hover {
    background-color: var(--border, #e2e8f0);
}

.btn-func {
    background-color: var(--border, #e2e8f0);
    color: var(--text-heading, #334155);
}

.btn-func:hover {
    background-color: #cbd5e1;
}

.btn-func.active {
    background-color: var(--accent, #2563eb);
    color: #ffffff;
}

.btn-op {
    background-color: #e0f2fe;
    color: #0369a1;
    border-color: #bae6fd;
}

.btn-op:hover {
    background-color: #bae6fd;
}

.btn-danger {
    background-color: #fee2e2;
    color: #dc2626;
    border-color: #fca5a5;
}

.btn-danger:hover {
    background-color: #fca5a5;
}

.btn-warning {
    background-color: #fef3c7;
    color: #d97706;
    border-color: #fde68a;
}

.btn-warning:hover {
    background-color: #fde68a;
}

.btn-action {
    background-color: var(--accent, #2563eb);
    color: #ffffff;
    border-color: var(--accent, #2563eb);
}

.btn-action:hover {
    background-color: #1d4ed8;
}

/* Dark Theme Overrides */
body.dark-theme .calculator-card {
    background-color: #1e293b;
    border-color: #334155;
}

body.dark-theme .page-title {
    color: #f8fafc;
}

body.dark-theme .page-subtitle {
    color: #94a3b8;
}

body.dark-theme .sci-calc {
    background-color: #0f172a;
    border-color: #334155;
}

body.dark-theme .unit-toggle {
    background: #1e293b;
    border-color: #334155;
}

body.dark-theme .btn-num {
    background-color: #1e293b;
    border-color: #334155;
    color: #f8fafc;
}

body.dark-theme .btn-num:hover {
    background-color: #334155;
}

body.dark-theme .btn-func {
    background-color: #334155;
    border-color: #475569;
    color: #cbd5e1;
}

body.dark-theme .btn-func:hover {
    background-color: #475569;
}

body.dark-theme .btn-op {
    background-color: #075985;
    border-color: #0369a1;
    color: #e0f2fe;
}

body.dark-theme .btn-op:hover {
    background-color: #0369a1;
}

/* Responsive Grid for Smaller Screens */
/* ═══════════════════════════════════════════════════════════
   Mobile Responsive Adjustments
   ═══════════════════════════════════════════════════════════ */

@media (max-width: 768px) {
    .calculator-card {
        margin: 15px auto;
        padding: 15px;
    }

    .sci-calc {
        padding: 12px;
    }

    .calc-screen {
        padding: 10px 14px;
    }

    .calc-input {
        font-size: 1.4rem;
    }

    /* Keypad 7 columns se reduce ho kar 5 columns adaptable ho jayega */
    .calc-keypad {
        grid-template-columns: repeat(5, 1fr);
        gap: 6px;
    }

    .btn {
        padding: 10px 2px;
        font-size: 0.82rem;
        border-radius: 6px;
    }
}

@media (max-width: 480px) {
    .calculator-card {
        padding: 10px;
    }

    .calc-keypad {
        grid-template-columns: repeat(4, 1fr); /* Chote screens par 4 columns */
        gap: 5px;
    }

    .btn {
        padding: 10px 0;
        font-size: 0.78rem;
    }

    .calc-mode-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
}