@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Roboto+Mono:wght@400;500;700&display=swap');

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f0f23 100%);
    min-height: 100vh;
}

/* Casio Button Styles */
.casio-btn {
    position: relative;
    height: 48px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.1s ease-out;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    select: none;
    border: none;
    overflow: visible;
}

.casio-btn .func-label {
    font-size: 9px;
    position: absolute;
    top: 2px;
    color: #d97706;
    font-weight: 600;
}

.casio-btn .main-label {
    font-size: 14px;
    margin-top: 6px;
}

.casio-btn:active {
    transform: scale(0.95);
}

/* Button Color Variants */
.shift-btn, .mode-btn, .alpha-btn {
    background: linear-gradient(145deg, #374151, #1f2937);
    color: #9ca3af;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.1);
}

.shift-btn .func-label, .mode-btn .func-label, .alpha-btn .func-label {
    color: #3b82f6;
}

.on-btn {
    background: linear-gradient(145deg, #059669, #047857);
    color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.2);
}

.on-btn .func-label {
    color: #fbbf24;
}

.action-btn {
    background: linear-gradient(145deg, #dc2626, #b91c1c);
    color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.2);
}

.action-btn .func-label {
    color: #fca5a5;
}

.func-btn {
    background: linear-gradient(145deg, #4b5563, #374151);
    color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.1);
}

.func-btn .func-label {
    color: #d97706;
}

.num-btn {
    background: linear-gradient(145deg, #1f2937, #111827);
    color: #e5e7eb;
    font-size: 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.4), inset 0 1px 0 rgba(255,255,255,0.05);
}

.op-btn {
    background: linear-gradient(145deg, #4b5563, #374151);
    color: #fbbf24;
    font-size: 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.1);
}

.equals-btn {
    background: linear-gradient(145deg, #3b82f6, #2563eb);
    color: white;
    font-size: 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.2);
}

/* Hover effects */
.casio-btn:hover {
    filter: brightness(1.1);
}

/* Custom Scrollbar */
.custom-scrollbar::-webkit-scrollbar {
    width: 4px;
}
.custom-scrollbar::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 2px;
}
.custom-scrollbar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 2px;
}
.custom-scrollbar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.25);
}

/* History Items */
.history-item {
    padding: 8px 10px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 12px;
    transition: all 0.2s;
    cursor: pointer;
}

.history-item:hover {
    background: rgba(99, 102, 241, 0.1);
    border-color: rgba(99, 102, 241, 0.3);
}

.history-item:hover .history-result {
    color: #818cf8;
}

.history-expression {
    color: #6b7280;
    margin-bottom: 2px;
}

.history-result {
    color: #e5e7eb;
    font-weight: 600;
    text-align: right;
}

/* Display styling for LCD effect */
#current-operand {
    font-family: 'Roboto Mono', monospace;
    letter-spacing: 1px;
}

/* Active state for buttons */
.casio-btn.pressed {
    filter: brightness(0.8);
    transform: scale(0.95);
}